Neuronetics (STIM) 10-Q 8 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Nov. 04, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2022
Document Transition Report	false
Entity File Number	001-38546
Entity Registrant Name	NEURONETICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-1051425
Entity Address, Address Line One	3222 Phoenixville Pike
Entity Address, City or Town	Malvern
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19355
City Area Code	610
Local Phone Number	640-4202
Title of 12(b) Security	Common Stock ($0.01 par value)
Trading Symbol	STIM
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		27,221,490
Entity Central Index Key	0001227636
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Ex Transition Period	false

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 73,698	$ 94,141
Accounts receivable, net	11,963	7,706
Inventory	8,573	6,563
Current portion of net investments in sales-type leases	1,874	2,198
Current portion of prepaid commission expense	1,871	1,559
Current portion of note receivables	80	74
Prepaid expenses and other current assets	3,037	3,090
Total current assets	101,096	115,331
Property and equipment, net	2,109	1,220
Operating lease right-of-use assets	3,459	3,884
Net investments in sales-type leases	1,617	1,697
Prepaid commission expense	7,305	6,763
Long-term note receivable	94	10,110
Other assets	3,555	2,218
Total Assets	119,235	141,223
Current liabilities:
Accounts payable	2,350	4,299
Accrued expenses	11,493	8,233
Deferred revenue	1,732	2,501
Current portion of operating lease liabilities	818	670
Current portion of long-term debt, net	8,750
Total current liabilities	25,143	15,703
Long-term debt, net	27,009	35,335
Deferred revenue	981	1,471
Operating lease liabilities	3,111	3,539
Total Liabilities	56,244	56,048
Commitments and contingencies (Note 17)
Stockholders' Equity:
Preferred stock, $0.01 par value: 10,000 shares authorized; no shares issued or outstanding on September 30, 2022, and December 31, 2021
Common stock, $0.01 par value: 200,000 shares authorized; 27,060 and 26,395 shares issued and outstanding on September 30, 2022, and December 31, 2021, respectively	270	264
Additional paid-in capital	400,323	393,644
Accumulated deficit	(337,602)	(308,733)
Total Stockholders' Equity	62,991	85,175
Total Liabilities and Stockholders' Equity	$ 119,235	$ 141,223

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Sep. 30, 2022	Dec. 31, 2021
Balance Sheets
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000	200,000
Common stock, shares issued	27,060	26,395
Common stock, shares outstanding	27,060	26,395

Statements of Operations

Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statements of Operations
Revenues	$ 16,498	$ 13,799	$ 47,008	$ 40,290
Cost of revenues	3,570	3,144	11,093	8,115
Gross Profit	12,928	10,655	35,915	32,175
Operating expenses:
Sales and marketing	11,643	9,827	37,977	27,431
General and administrative	6,391	6,435	19,125	19,220
Research and development	2,348	1,575	6,197	6,179
Total operating expenses	20,382	17,837	63,299	52,830
Loss from Operations	(7,454)	(7,182)	(27,384)	(20,655)
Other (income) expense:
Interest expense	1,061	993	3,039	2,955
Other income, net	(906)	(24)	(1,554)	(53)
Net Loss	$ (7,609)	$ (8,151)	$ (28,869)	$ (23,557)
Net loss per share of common stock outstanding, basic	$ (0.28)	$ (0.31)	$ (1.08)	$ (0.94)
Net loss per share of common stock outstanding, diluted	$ (0.28)	$ (0.31)	$ (1.08)	$ (0.94)
Weighted-average common shares outstanding, basic	26,965	26,301	26,797	25,179
Weighted-average common shares outstanding, diluted	26,965	26,301	26,797	25,179

Statements of Changes in Stockh

Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Total
Beginning balance at Dec. 31, 2020	$ 191	$ 302,842	$ (277,540)	$ 25,493
Beginning balance, shares at Dec. 31, 2020	19,114
Share-based awards and options exercises	$ 11	1,581		1,592
Share-based awards and options exercises, shares	1,076
Issuance of common stock	$ 56	80,515		80,571
Issuance of common stock (in shares)	5,566
Share-based compensation expense		2,196		2,196
Net Loss			(7,881)	(7,881)
Ending balance at Mar. 31, 2021	$ 258	387,134	(285,421)	101,971
Ending balance, shares at Mar. 31, 2021	25,756
Beginning balance at Dec. 31, 2020	$ 191	302,842	(277,540)	25,493
Beginning balance, shares at Dec. 31, 2020	19,114
Net Loss				(23,557)
Ending balance at Sep. 30, 2021	$ 263	391,910	(301,097)	91,076
Ending balance, shares at Sep. 30, 2021	26,335
Beginning balance at Mar. 31, 2021	$ 258	387,134	(285,421)	101,971
Beginning balance, shares at Mar. 31, 2021	25,756
Share-based awards and options exercises	$ 4	707		711
Share-based awards and options exercises, shares	411
Share-based compensation expense		2,009		2,009
Net Loss			(7,525)	(7,525)
Ending balance at Jun. 30, 2021	$ 262	389,850	(292,946)	97,166
Ending balance, shares at Jun. 30, 2021	26,167
Share-based awards and options exercises	$ 1	99		100
Share-based awards and options exercises, shares	168
Share-based compensation expense		1,961		1,961
Net Loss			(8,151)	(8,151)
Ending balance at Sep. 30, 2021	$ 263	391,910	(301,097)	91,076
Ending balance, shares at Sep. 30, 2021	26,335
Beginning balance at Dec. 31, 2021	$ 264	393,644	(308,733)	85,175
Beginning balance, shares at Dec. 31, 2021	26,395
Share-based awards and options exercises	$ 3	6		9
Share-based awards and options exercises, shares	322
Share-based compensation expense		2,252		2,252
Net Loss			(10,838)	(10,838)
Ending balance at Mar. 31, 2022	$ 267	395,902	(319,571)	76,598
Ending balance, shares at Mar. 31, 2022	26,717
Beginning balance at Dec. 31, 2021	$ 264	393,644	(308,733)	85,175
Beginning balance, shares at Dec. 31, 2021	26,395
Net Loss				(28,869)
Ending balance at Sep. 30, 2022	$ 270	400,323	(337,602)	62,991
Ending balance, shares at Sep. 30, 2022	27,060
Beginning balance at Mar. 31, 2022	$ 267	395,902	(319,571)	76,598
Beginning balance, shares at Mar. 31, 2022	26,717
Share-based awards and options exercises	$ 1	42		43
Share-based awards and options exercises, shares	139
Share-based compensation expense		2,203		2,203
Net Loss			(10,422)	(10,422)
Ending balance at Jun. 30, 2022	$ 268	398,147	(329,993)	68,422
Ending balance, shares at Jun. 30, 2022	26,856
Share-based awards and options exercises	$ 2	(2)
Share-based awards and options exercises, shares	204
Share-based compensation expense		2,178		2,178
Net Loss			(7,609)	(7,609)
Ending balance at Sep. 30, 2022	$ 270	$ 400,323	$ (337,602)	$ 62,991
Ending balance, shares at Sep. 30, 2022	27,060

Statements of Changes in Stoc_2

Statements of Changes in Stockholders' Equity (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Statements of Changes in Stockholders' Equity (Deficit)
Issuance of common stock, issuance costs	$ 401

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Cash Flows from Operating Activities:
Net loss	$ (28,869)	$ (23,557)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,044	768
Share-based compensation	6,633	6,166
Non-cash interest expense	513	484
Cost of rental units purchased by customers	92	137
Changes in certain assets and liabilities:
Accounts receivable, net	(4,257)	(3,097)
Inventory	(2,299)	(1,870)
Net investments in sales-type leases	381	341
Prepaid commission expense	(854)	(602)
Prepaid expenses and other assets	176	(453)
Accounts payable	(2,199)	(840)
Accrued expenses	3,260	(405)
Deferred revenue	(1,260)	(531)
Net Cash Used in Operating Activities	(27,639)	(23,459)	$ (28,000)
Cash Flows from Investing Activities:
Purchases of property and equipment and capitalized software	(2,766)	(1,552)
Repayment (Issuance) of promissory note	10,000
Repayment (Issuance) of promissory note		(7,486)
Net Cash provided by (used in) Investing Activities	7,234	(9,038)
Cash Flows from Financing Activities:
Payments of debt issuance costs	(90)
Proceeds from exercises of stock options	52	2,403
Proceeds from the issuance of common stock		80,972
Payments of common stock offering issuance costs		(401)
Net Cash (used in) Provided by Financing Activities	(38)	82,974
Net (Decrease) Increase in Cash and Cash Equivalents	(20,443)	50,477
Cash and Cash Equivalents, Beginning of Period	94,141	48,957	48,957
Cash and Cash Equivalents, End of Period	73,698	99,434	$ 94,141
Supplemental disclosure of cash flow information:
Cash paid for interest	2,525	2,471
Transfer of Inventory to PP&E	285	235
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property and equipment and capitalized software in accounts payable and accrued expenses	$ 251	398
Reduction of accounts receivable in long-term note receivable		$ 2,514

Description of Business

Description of Business	9 Months Ended
	Sep. 30, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	1. DESCRIPTION OF BUSINESS Neuronetics, Inc., or the Company, is a commercial stage medical technology company focused on designing, developing and marketing products that improve the quality of life for patients who suffer from neurohealth disorders. The Company’s first commercial product, the NeuroStar Advanced Therapy System, is a non-invasive and non-systemic office-based treatment that uses transcranial magnetic stimulation, or TMS, to create a pulsed, MRI-strength magnetic field that induces electrical currents designed to stimulate specific areas of the brain associated with mood. The system was cleared in 2008 by the United States Food and Drug Administration, or the FDA, to treat adult patients with major depressive disorder, or MDD, who have failed to achieve satisfactory improvement from prior antidepressant medication in the current episode. Our NeuroStar Advanced Therapy system was also cleared in 2022 by the FDA to treat people suffering from obsessive-compulsive disorder as well as for the treatment of comorbid anxiety symptoms for adults with MDD suffering from anxiety symptoms (“anxious depression”). NeuroStar Advanced Therapy is also available in other parts of the world, including Japan, where it is listed under Japan’s national health insurance. The Company intends to continue to pursue development of its NeuroStar Advanced Therapy System for additional indications. COVID-19 The Company is continuing to monitor the impact of the COVID-19 pandemic on all aspects of its business and geographies, including how it will continue to impact the Company’s customers, supply chain, employees and other business partners. While the Company experienced significant disruptions in March 2020 through the end of September 30, 2022 from the COVID-19 pandemic, it is unable to predict the full impact that the pandemic may have on its financial condition, results of operations and cash flows due to numerous uncertainties. These uncertainties include the scope, severity and duration of the ongoing pandemic, the actions taken to contain the pandemic or mitigate its impact and the direct and indirect economic effects of the pandemic, vaccination rates, effectiveness of treatments, and containment measures, among others. The pandemic has significantly adversely impacted global economic activity and has contributed to significant volatility and negative pressure in financial markets, and may contribute to periods of economic uncertainty in the future. Liquidity As of September 30, 2022, the Company had cash and cash equivalents of $73.7 million and an accumulated deficit of $337.6 million. The Company incurred negative cash flows from operating activities of $27.6 million for the nine months ended September 30, 2022 and $28.0 million for the year ended December 31, 2021. The Company has incurred operating losses since its inception, and management anticipates that its operating losses will continue in the near term as the Company continues to invest in sales, marketing and product development activities. The Company’s primary sources of capital to date have been proceeds from its initial public offering (“IPO”) of common stock, private placements of its convertible preferred securities, borrowings under its credit facility, proceeds from its secondary public offering of common stock and revenues from sales of its products. As of September 30, 2022, the Company had $35.0 million of borrowings outstanding under its credit facility, which has a final maturity in February 2025

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation	2. BASIS OF PRESENTATION The accompanying financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification, or ASC, and Accounting Standards Updates, or ASUs, promulgated by the Financial Accounting Standards Board, or FASB. Interim Financial Statements The accompanying unaudited interim financial statements have been prepared from the books and records of the Company in accordance with GAAP for interim financial information and Rule 10-01 of Regulation S-X promulgated by the United States Securities and Exchange Commission, or SEC, which permit reduced disclosures for interim periods. All adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the accompanying balance sheets and statements of operations and stockholders’ equity and cash flows have been made. Although these interim financial statements do not include all of the information and footnotes required for complete annual financial statements, management believes the disclosures are adequate to make the information presented not misleading. Unaudited interim results of operations and cash flows for the three and nine months ended September 30, 2022 are not necessarily indicative of the results that may be expected for the full year. Unaudited interim financial statements and footnotes should be read in conjunction with the audited financial statements and footnotes included in the Company’s Form 10-K filed with the SEC on March 8, 2022, wherein a more complete discussion of significant accounting policies and certain other information can be found. Use of Estimates The preparation of financial statements in accordance with GAAP and the rules and regulations of the SEC requires the use of estimates and assumptions, based on judgments considered reasonable, which affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The Company bases its estimates and assumptions on historical experience, known trends and events and various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Although management believes its estimates and assumptions are reasonable when made, they are based upon information available at the time they are made. Management evaluates the estimates and assumptions on an ongoing basis and, if necessary, makes adjustments. Due to the risks and uncertainties involved in the Company’s business and evolving market conditions, including those related to the COVID-19 pandemic, and given the subjective element of the estimates and assumptions made, actual results may differ materially from estimated results.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The Company’s complete summary of significant accounting policies can be found in “Note 3. Summary of Significant Accounting Policies” in the audited financial statements included in the Company’s Form 10-K filed with the SEC on March 8, 2022.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2022
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Recent Accounting Pronouncements	4. RECENT ACCOUNTING PRONOUNCEMENTS New Accounting Standards Not Yet Adopted by the Company In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments “Topic 326” ASU 2019-04, ASU 2019-05, Financial Instruments - Credit Losses (Topic 326) : Targeted Transition Relief , was issued to provide entities that have certain instruments within the scope of ASC 326 with an option to irrevocably elect the fair value option under ASC 825-10, Financial Instruments - Overall , applied on an instrument-by-instrument basis for eligible instruments ASU 2019-10, Topic 326, Topic 815, and Topic 842 amends the mandatory effective date for Topic 326. These ASUs are effective for fiscal years beginning after December 15, 2022 for entities that are eligible to be defined by the SEC as a smaller reporting company. The Company is a smaller reporting company. Although the impact upon adoption will depend on the financial instruments held by the Company at that time, the Company does not anticipate a significant impact on its financial statements based on the instruments currently held and its historical trend of bad debt expense relating to trade accounts receivable. ​ Other than the items noted above, there have been no new accounting pronouncements not yet effective or adopted in the current year that we believe have a significant impact, or potential significant impact, to our unaudited interim financial statements.

Fair Value Measurement and Fina

Fair Value Measurement and Financial Instruments	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurement and Financial Instruments	5. FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS The carrying values of cash equivalents, accounts receivable, prepaids and other current assets, and accounts payable on the Company’s balance sheets approximated their fair values as of September 30, 2022 and December 31, 2021 due to their short-term nature. The carrying values of the Company’s credit facility approximated its fair value as of September 30, 2022 and December 31, 2021 due to its variable interest rate. The carrying value of the Company’s note receivable approximated its fair value as of December 31, 2021 due to its variable interest rate. Certain of the Company’s financial instruments are measured at fair value using a three-level hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable inputs and minimizes the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: Level 1 Inputs are quoted prices for identical instruments in active markets. Level 2 Inputs are quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; or model-derived valuations whose inputs are observable or whose significant value drivers are observable. Level 3 Inputs are unobservable and reflect the Company’s own assumptions, based on the best information available, including the Company’s own data . The following tables set forth the carrying amounts and fair values of the Company’s financial instruments as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement Based on ​ ​ ​ ​ ​ ​ ​ ​ Quoted ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Prices In ​ other ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ Active ​ Observable ​ Unobservable ​ ​ Carrying ​ ​ ​ ​ Markets ​ Inputs ​ Inputs ​ Amount Fair Value (Level 1) (Level 2) (Level 3) Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds (cash equivalents) ​ $ 69,405 ​ $ 69,405 ​ $ 69,405 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement Based on ​ ​ ​ ​ ​ ​ ​ ​ Quoted ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Prices In ​ other ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ Active ​ Observable ​ Unobservable ​ ​ Carrying ​ ​ ​ ​ Markets ​ Inputs ​ Inputs ​ ​ Amount ​ Fair Value ​ (Level 1) ​ (Level 2) ​ (Level 3) Assets ​ ​ ​ ​ ​ Money market funds (cash equivalents) ​ $ 91,236 ​ $ 91,236 ​ $ 91,236 ​ $ — ​ $ — ​

Accounts Receivable

Accounts Receivable	9 Months Ended
	Sep. 30, 2022
Receivables [Abstract]
Accounts Receivable	6. ACCOUNTS RECEIVABLE The following table presents the composition of accounts receivable, net as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2022 2021 Gross accounts receivable - trade ​ $ 13,754 ​ $ 9,168 Less: Allowances for doubtful accounts ​ (1,791) ​ (1,462) Accounts receivable, net ​ $ 11,963 ​ $ 7,706 ​

Property and Equipment and Capi

Property and Equipment and Capitalized Software	9 Months Ended
	Sep. 30, 2022
Property Plant And Equipment [Abstract]
Property and Equipment and Capitalized Software	7. PROPERTY AND EQUIPMENT AND CAPITALIZED SOFTWARE The following table presents the composition of property and equipment, net as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2022 2021 ​ Laboratory equipment ​ $ 466 ​ $ 249 ​ Office equipment ​ 508 ​ 497 ​ Computer equipment and software ​ 1,711 ​ 1,598 ​ Manufacturing equipment ​ 344 ​ 341 ​ Leasehold improvements ​ 1,422 ​ 471 ​ Rental equipment ​ 575 ​ 601 ​ Property and equipment, gross ​ 5,026 ​ 3,757 ​ Less: Accumulated depreciation ​ (2,917) ​ (2,537) ​ Property and equipment, net ​ $ 2,109 ​ $ 1,220 ​ ​ As of September 30, 2022 and December 31, 2021, the Company had capitalized software costs, net of $3.7 million and $2.5 million, respectively, which are included in “Prepaid expenses and other current assets” and “Other assets” on the balance sheet. Depreciation and amortization expense was $0.4 million and $0.2 million for the three months ended September 30, 2022 and 2021, respectively, and $1.0 million and $0.8 million for the nine months ended September 30, 2022 and 2021, respectively.

Note Receivable

Note Receivable	9 Months Ended
	Sep. 30, 2022
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]
Note Receivable	8. NOTE RECEIVABLE On September 29, 2021, Neuronetics, Inc. the Company entered into an exclusive, five-year master sales agreement (the “Commercial Agreement”) with Check Five, LLC d/b/a Success TMS (“Success TMS”). In connection with the Commercial Agreement, the Company agreed to loan Success TMS the principal amount of $10.0 million for a period of five years pursuant to a secured promissory note (the “Note”). The Note bore interest at a floating rate equal to the prime rate plus 6.00% per annum. The Note included an interest-only period through October 1, 2022, after which time Success TMS was required to make monthly payments of principal and interest. Under the terms of the Note, the Company had received a first priority security interest in substantially all of the assets of Success TMS. Success TMS has also granted the Company an observer seat on the Board of Managers of Success TMS. In the Note, Success TMS made certain representations and warranties and was required to comply with certain customary affirmative and negative covenants during the term of the Note. On April 29, 2022, the Company entered into a Subordination Agreement (the “Subordination Agreement”) with ZW Partners, LLC, a New Jersey limited liability company (“ZW Partners”), pursuant to which the Company agreed to subordinate its rights under the Note to the rights of ZW Partners under a revolving promissory note, dated as of April 29, 2022 (the “Senior Note”), issued by Success TMS to ZW Partners in an amount up to $10.0 million. As a result, payments in respect of the Note were subordinate and subject in right and time of payment to payment in full of the Senior Note, and ZW Partners’ liens and security interests upon the collateral securing both the Senior Note and the Note are superior in priority to the Company’s liens and security interests upon such collateral. Under the Agreement, the Company had the right to purchase, at par, the entire aggregate amount of debt under the Senior Note at any time. On July 14, 2022, Success TMS repaid in full the Note issued on September 29, 2021 with a cash payment of $10.5 million, which included all outstanding principal, prepayment premium and accrued but unpaid interest. The repayment extinguished the Note in its entirety and terminated the Subordination Agreement entered into by the Company and ZW Partners. Interest income recognized by the Company was $0.5 million and $1.0 million for the three and nine months ended September 30, 2022, respectively.

Leases

Leases	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Leases	9. LEASES Lessee: The Company has operating leases for its corporate headquarters, a training facility and office equipment, including copiers. The Company leases an approximately 32,000 square foot facility in Malvern, Pennsylvania for its corporate headquarters, which includes office and warehouse space. The Company leases an approximately 9,600 square foot facility in Charlotte, North Carolina as a training facility for its NeuroStar Advanced Therapy Systems. The Company does not currently have any finance leases or executed leases that have not yet commenced. Operating lease rent expense was $0.2 million and $0.2 million for the three months ended September 30, 2022 and 2021, respectively, and $0.6 million and $0.4 million for the nine months ended September 30, 2022 and 2021, respectively. As of September 30, 2022, the weighted-average remaining lease term of operating leases was 5.3 years and the weighted-average discount rate was 7.1%. The following table presents the supplemental cash flow information as a lessee related to leases (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ ​ September 30, 2022 September 30, 2021 ​ Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ Operating cash flows from operating leases ​ $ 632 ​ $ 526 ​ ​ The following table sets forth by year the required future payments of operating lease liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ September 30, 2022 Remainder of 2022 ​ $ 209 2023 ​ ​ 852 2024 ​ 875 2025 ​ 898 2026 ​ 921 Thereafter ​ 999 Total lease payments ​ 4,754 Less imputed interest ​ (825) Present value of operating lease liabilities ​ $ 3,929 ​ Lessor sales-type leases: Certain customers have purchased NeuroStar Advanced Therapy Systems on a rent-to-own basis. The lease term is three The following table sets forth the profit recognized on sales-type leases (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ 2022 2021 2022 2021 Profit recognized at commencement, net ​ $ 122 ​ $ 262 ​ $ 543 ​ $ 543 Interest income ​ — ​ — ​ — ​ — Total sales-type lease income ​ $ 122 ​ $ 262 ​ $ 543 ​ $ 543 ​ The following table sets forth a maturity analysis of the undiscounted lease receivables related to sales-type leases (in thousands): ​ ​ ​ ​ ​ ​ September 30, ​ ​ 2022 Remainder of 2022 ​ $ 605 2023 ​ ​ 1,572 2024 ​ 858 2025 ​ 368 2026 ​ ​ 88 Total sales-type lease receivables ​ $ 3,491 ​ As of September 30, 2022, the carrying amount of the lease receivables is $3.5 million. The Company does not have any unguaranteed residual assets. Lessor operating leases: NeuroStar Advanced Therapy Systems sold for which collection is not probable are accounted for as operating leases. For the three months ended September 30, 2022 and 2021, the Company recognized operating lease income of $0.07 million and $0.03 million, respectively. For the nine months ended September 30, 2022 and 2021, the Company recognized operating lease income of $0.2 million and $0.2 million, respectively. The Company maintained Rental Equipment, net of $0.5 million and $0.6 million as of September 30, 2022 and December 31, 2021, respectively, which are included in “Property and equipment, net” on the balance sheet. Rental equipment depreciation expense was $0.02 million and $0.01 million for the three months ended September 30, 2022 and 2021, respectively, and $0.07 million and $0.03 million for the nine months ended September 30, 2022 and 2021.

Prepaid Commission Expense

Prepaid Commission Expense	9 Months Ended
	Sep. 30, 2022
Amortization Of Deferred Charges [Abstract]
Prepaid Commission Expense	10. PREPAID COMMISSION EXPENSE The Company pays a commission on both NeuroStar Advanced System sales and Treatment Session sales. Since the commission paid for System sales is not commensurate with the commission paid for Treatment Sessions, the Company capitalizes commission expense associated with NeuroStar Advanced Therapy System sales commissions paid that is incremental to specifically anticipated future Treatment Session orders. In developing this estimate, the Company considered its historical Treatment Session sales and customer retention rates, as well as technology development life cycles and other industry factors. These costs are periodically reviewed for impairment. NeuroStar Advanced Therapy System commissions are deferred and amortized on a straight-line basis over a seven-year period equal to the average customer term, which the Company deems to be the expected period of benefit for these costs. On the Company’s balance sheets, the current portion of capitalized contract costs is represented by the current portion of prepaid commission expense, while the long-term portion is included in prepaid commission expense. Amortization expense was $0.5 million and $0.3 million for the three months ended September 30, 2022 and 2021, respectively, and $1.3 million and $0.9 million for the nine months ended September 30, 2022 and 2021, respectively.

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2022
Payables And Accruals [Abstract]
Accrued Expenses	11. ACCRUED EXPENSES The following table presents the composition of accrued expenses as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2022 ​ 2021 Compensation and related benefits ​ $ 8,022 ​ $ 5,090 Consulting and professional fees ​ 760 ​ 537 Research and development expenses ​ 637 ​ 388 Sales and marketing expenses ​ ​ 246 ​ ​ 268 Warranty ​ 337 ​ 306 Sales and other taxes payable ​ 558 ​ 664 Other ​ 933 ​ 980 Accrued expenses ​ $ 11,493 ​ $ 8,233 ​

Deferred Revenue

Deferred Revenue	9 Months Ended
	Sep. 30, 2022
Deferred Revenue [Abstract]
Deferred Revenue	12. DEFERRED REVENUE Payment terms typically require payment upon shipment or installation of the System and additional payments as access codes for Treatment Sessions are delivered, which can span several years after the System is first delivered and installed. The timing of revenue recognition compared to billings and cash collections typically results in accounts receivable. However, sometimes customer advances and deposits might be required for certain customers and are recorded as contract liabilities (deferred revenue). For multi-year agreements, the Company generally invoices customers annually at the beginning of each annual coverage period and recognizes revenue over the term of the coverage period. As of September 30, 2022, the Company expects to recognize approximately the following percentages of deferred revenue by year: ​ ​ ​ ​ ​ ​ Revenue Year: ​ Recognition Remainder of 2022 ​ 25 % 2023 40 % 2024 25 % 2025 8 % 2026 ​ 2 % Total 100 % ​ Customers For the three months ended September 30, 2022 and 2021, one customer accounted for more than 10% of the Company’s revenues, respectively. For the nine months ended September 30, 2022 and 2021, one customer accounted for more than 10% of the Company’s revenues, respectively.

Debt

Debt	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Debt	13. DEBT The following table presents the composition of debt as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2022 2021 ​ Outstanding principal ​ $ 35,000 ​ $ 35,000 ​ Accrued final payment fees ​ 1,925 ​ 1,925 ​ Less debt discounts ​ (1,166) ​ (1,590) ​ Total debt, net ​ 35,759 ​ 35,335 ​ Less current portion ​ (8,750) ​ — ​ Long-term debt, net ​ $ 27,009 ​ $ 35,335 ​ ​ For the three months ended September 30, 2022, the Company recognized interest expense of $1.1 million, of which $0.9 million was cash and $0.2 million was non-cash interest expense related to the amortization of deferred debt issuance costs and accrual of final payment fees. For the three months ended September 30, 2021, the Company recognized interest expense of $1.0 million, of which $0.8 million was cash and $0.2 million was non-cash interest expense related to the amortization of deferred debt issuance costs and accrual of final payment fees. For the nine months ended September 30, 2022, the Company recognized interest expense of $3.0 million, of which $2.5 million was cash and $0.5 million was non-cash interest expense related to the amortization of deferred debt issuance costs and accrual of final payment fees. Solar Credit Facility On March 2, 2020, the Company entered into a loan and security agreement with Solar Capital Ltd., or Solar, as collateral agent, and other lenders defined in the agreement, for a credit facility, or the Solar Facility, that replaced the Company’s previous $35.0 million credit facility with Oxford Finance LLC, or Oxford, and such facility, the Oxford Facility. The Solar Facility originally permitted the Company to borrow up to an aggregate amount of $50.0 million in two tranches of term loans, a “Term A Loan” and “Term B Loan.” On March 2, 2020, the Company borrowed an aggregate amount of $35.0 million, which was the aggregate amount available under the Term A Loan portion of the Solar Facility. The Term A Loan portion of the Solar Facility matures, and all amounts borrowed thereunder are due, on February 28, 2025. Under the Term B Loan portion of the Solar Facility, the Company is permitted to borrow, at its election, up to an aggregate amount of $15.0 million, (i) upon the Company achieving a specified amount of trailing twelve Each of the Term A Loan and Term B Loan accrue interest from the date of borrowing through the date of repayment at a floating per annum rate of interest, which resets monthly and is equal to 7.65% plus the greater of (a) 1.66% or (b) the rate per annum rate published by the Intercontinental Exchange Benchmark Administration Ltd. The Term A Loan and the Term B Loan both include an interest-only period through March February 2023 In addition to the principal and interest payments due under the Solar Facility, the Company is required to pay a final payment fee to Solar due upon the earlier of prepayment, acceleration or the maturity date of the Term A Loan or Term B Loan portion of the Solar Facility equal to 5.50% of the principal amount of the term loans actually funded. The Company is accruing the final payment fees using the effective interest rate, with a charge to non-cash interest expense, over the term of borrowing. If the Company prepays either of the Term A Loan or Term B Loan prior to their respective scheduled maturities, the Company will also be required to pay prepayment fees to Solar equal to 3% of the principal amount of such term loan then-prepaid if prepaid on or before the first anniversary of funding, 2% of the principal amount of such term loan then-prepaid if prepaid after the first anniversary and on or before the second anniversary of funding, or 1% of the principal amount of such term loan then-prepaid if prepaid after the second anniversary of funding of the principal amounts borrowed. The Company is also required to pay Solar an exit fee upon the occurrence, prior to March 2, 2030, of (a) any liquidation, dissolution or winding up of the Company, (b) transaction that results in a person obtaining control over the Company, (c) the Company achieving $100 million in trailing twelve month net product revenue or (d) the Company achieving $125 million in trailing twelve month net product revenue. The exit fee for liquidation, dissolution, winding up or change of control of the Company is equal to 4.50% of the principal amount of the term loans actually funded. The exit fee for achieving either $100 million or $125 million in trailing twelve-month net product revenue is equal to 2.25% of the principal amount of the term loans actually funded or, if both net product revenue milestones are achieved, 4.50% of the principal amount of the term loans actually funded. The exit fee is capped at 4.50% of the principal amount of the term loans actually funded. The Company’s obligations under the Solar Facility are secured by a first priority security interest in substantially all of its assets, including its intellectual property. The loan and security agreement requires the Company to comply with certain financial covenants, including the attainment of a minimum trailing net revenue amount beginning on December 31, 2020, as well as customary affirmative and negative covenants. The Solar Facility contains events of default, including, without limitation, events of default upon: (i) failure to make payment pursuant to the terms of the agreement; (ii) violation of covenants; (iii) material adverse changes to the Company’s business; (iv) attachment or levy on the Company’s assets or judicial restraint on its business; (v) insolvency; (vi) material cross-defaults; (vii) significant judgments, orders or decrees for payments by the Company not covered by insurance; (viii) incorrectness of representations and warranties; (ix) incurrence of subordinated debt; (x) a termination or breach of a guaranty; (xi) revocation of governmental approvals necessary for the Company to conduct its business; and (xii) failure by the Company to maintain a valid and perfected lien on the collateral securing the borrowing. The Solar Facility includes subjective acceleration clauses which permit the lenders to accelerate the maturity date under certain circumstances, including, but not limited to, material adverse effects on a Company’s financial status or otherwise. On December 8, 2020, the Company, Solar Capital Ltd., and our other lenders defined in the Solar Facility, executed an amendment to the Solar Facility (the “Solar Amendment”). The Solar Amendment divided the aggregate Term B Loan borrowing amount of $15.0 million allowable upon our achievement of specific trailing twelve-month net product revenue targets into three separate $5.0 million tranches (“Amended Term B Loan”, “Term C Loan” and “Term D Loan”). The three tranches are available through June 20, 2021, December 20, 2021, and June 20, 2022, respectively, based on the achievement of agreed upon trailing twelve-month net product revenue targets for each tranche. The Solar Amendment also reduced the trailing twelve-month net product revenue requirement for the Amended Term B Loan portion of the facility. Subject to certain conditions, the Company has the ability to extend the interest only period on the initial Term A Loan to 36 months from 24 months upon achieving the revenue targets associated with the Amended Term B Loan. The Company was required to pay an amendment fee of $0.1 million to Solar, which was recognized as a deferred debt issuance cost as of December 31, 2020 that will be amortized to interest expense using the effective interest method. On February 15, 2022, the Company, SLR Investment Corp. (formerly known as Solar Capital Ltd.) (“Solar”), and our other lenders defined in the Solar Facility, executed an amendment to the Solar Facility and the Solar Amendment (the “2022 Solar Amendment”). The 2022 Solar Amendment waived any default under the Solar Facility and Solar Amendment that resulted from the Company’s failure to comply with the minimum monthly trailing twelve months net product revenue financial covenant, beginning with the testing period for the calendar month ending December 31, 2021 and continuing to the execution date of the 2022 Solar Amendment; (ii) decreased the amount of trailing twelve months net product revenue that the Company is required to achieve, for testing periods on and from the calendar month ending January 31, 2022; (iii) modified the definition of the fourth draw period with respect to the Company’s ability to borrow the Term D Loan portion of the Solar Facility, such that after giving effect to the 2022 Solar Amendment, the Term D Loan portion of the Solar Facility is no longer available to be drawn by the Company; and (iv) modified the definition of interest only extension conditions to allow commencement of loan principal amortization under the Solar Facility to be extended to March 1, 2023. The Company was required to pay an amendment fee of $0.06 million to Solar, which has been recognized as a deferred debt issuance cost as of March 31, 2022 that will be amortized to interest expense using the effective interest method. As of September 30, 2022, the Company is in compliance with all covenants in the Solar Facility and is projected to be in compliance with the reduced minimum revenue covenant amounts going forward.

Common Stock

Common Stock	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Common Stock	14. COMMON STOCK Common Stock Offering On February 2, 2021, we closed on our public offering and sale (the “Offering”) of our common stock in which we issued and sold 5,566,000 shares of our common stock, which included shares pursuant to an option granted to underwriters to purchase additional shares, at a public offering price of $15.50 per share. We received net proceeds of $80.6 million after deducting underwriting discounts, commissions and offering expenses. Common Stock The following table summarizes the total number of shares of the Company’s common stock issued and reserved for issuance as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ September 30, 2022 December 31, 2021 Shares of common stock issued 27,060 26,395 Shares of common stock reserved for issuance for: Common stock warrants outstanding 75 75 Stock options outstanding 1,424 1,499 Restricted stock units outstanding 4,060 2,124 Shares available for grant under stock incentive plan 1,067 2,037 Shares available for sale under employee stock purchase plan 1,063 799 Total shares of common stock issued and reserved for issuance 34,749 32,929 ​ Common Stock Warrants The following tables summarize the Company’s outstanding common stock warrants as of September 30, 2022, and December 31, 2021: ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ Warrants ​ Outstanding ​ ​ ​ ​ ​ (in thousands) ​ Exercise Price ​ Expiration Date 14 ​ $ 19.55 Dec-2022 20 ​ $ 9.73 Aug-2023 20 ​ $ 9.73 Mar-2024 21 ​ $ 9.73 Dec-2024 75 ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Warrants ​ Outstanding ​ ​ ​ ​ ​ (in thousands) ​ Exercise Price ​ Expiration Date 14 ​ $ 19.55 Dec-2022 20 ​ $ 9.73 Aug-2023 20 ​ $ 9.73 Mar-2024 21 ​ $ 9.73 Dec-2024 75 ​ ​

Loss Per Share

Loss Per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Loss Per Share	15. LOSS PER SHARE The Company’s basic loss per common share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period. The Company’s restricted stock awards (non-vested shares) are issued and outstanding at the time of grant but are excluded from the Company’s computation of weighted-average shares outstanding in the determination of basic loss per share until vesting occurs. A net loss cannot be diluted, so when the Company is in a net loss position, basic and diluted loss per common share are the same. If in the future the Company achieves profitability, the denominator of a diluted earnings per common share calculation will include both the weighted-average number of shares outstanding and the number of common stock equivalents, if the inclusion of such common stock equivalents would be dilutive. Dilutive common stock equivalents potentially include warrants, stock options, non-vested restricted stock units and non-vested performance restricted stock units using the treasury stock method, along with the effect, if any, from the potential conversion of outstanding securities, such as convertible preferred stock. The following potentially dilutive securities outstanding as of September 30, 2022 and 2021 have been excluded from the denominator of the diluted loss per share of common stock outstanding calculation (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ 2022 2021 ​ Stock options ​ 1,424 ​ 1,567 ​ Non-vested performance restricted stock units 395 395 ​ Non-vested restricted stock units 3,665 1,647 ​ Common stock warrants 75 75 ​ ​

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2022
Disclosure Of Compensation Related Costs Share-based Payments [Abstract]
Share-Based Compensation	16. SHARE-BASED COMPENSATION The amount of share-based compensation expense recognized by the Company by location in its statements of operations for the three and nine months ended September 30, 2022 and 2021 is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ ​ 2022 2021 2022 2021 ​ Cost of revenues ​ $ 35 ​ $ 23 ​ $ 94 ​ ​ 56 ​ Sales and marketing ​ 1,074 ​ 515 ​ 3,258 ​ ​ 1,608 ​ General and administrative ​ 939 ​ 1,368 ​ 2,950 ​ ​ 4,368 ​ Research and development ​ 130 ​ 55 ​ 331 ​ ​ 134 ​ Total ​ $ 2,178 ​ $ 1,961 ​ $ 6,633 ​ $ 6,166 ​ ​ 2018 Equity Incentive Plan In June 2018, the Company adopted the 2018 Equity Incentive Plan, or 2018 Plan, which authorized the issuance of up to 1.4 million shares, subject to an annual 4% increase based on the number of shares of common stock outstanding, in the form of restricted stock, stock appreciation rights and stock options to the Company’s directors, employees and consultants. The amount and terms of grants are determined by the Company’s board of directors. All stock options granted to date have had exercise prices equal to the fair value, as determined by the closing price as reported by the Nasdaq Global Market, of the underlying common stock on the date of grant. The contractual term of stock options is up to 10 years, and stock options are exercisable in cash or as otherwise determined by the board of directors. Generally, stock options vest 25% upon the first anniversary of the date of grant and the remainder ratably monthly thereafter for 36 months. Restricted stock units generally vest ratably in three equal installments on the first, second and third anniversaries of the grant date. Performance restricted stock units (“PRSUs”) generally vest based on appreciation of the Company’s common stock to a certain price as determined by the Company’s board of directors measured using a trailing 30-day volume weighted average price of a share of the Company’s common stock. The fair value of the PRSU awards are determined using a risk neutral Monte Carlo simulation valuation model. As of September 30, 2022, there were 0.6 million shares available for future issuance under the 2018 Plan. 2020 Inducement Incentive Plan In December 2020, the Company adopted the 2020 Inducement Incentive Plan, which authorized the issuance of up to 0.4 million shares, subject to increase by approval of the Company’s board of directors, in the form of stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards and other stock awards to eligible employees who satisfy the standards for inducement grants under Nasdaq Global Market rules. In March 2022, the Company’s board of directors approved an additional 500,000 shares for the issuance under the plan. An individual who previously served as an employee or director of the Company is not eligible to receive awards under this plan. The amount and terms of grants are determined by the Company’s board of directors. As of September 30, 2022, there were 0.5 million shares available for future issuance under the 2020 Inducement Incentive Plan. Stock Options The following table summarizes the Company’s stock option activity for the nine months ended September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aggregate ​ ​ Number of ​ Weighted- ​ Weighted- ​ average ​ ​ Shares under ​ average ​ Remaining ​ Intrinsic ​ ​ Option ​ Exercise Price ​ Contractual ​ Value ​ ​ (in thousands) ​ per Option ​ Life (in years) ​ (in thousands) Outstanding at December 31, 2021 1,499 ​ $ 4.01 ​ ​ ​ Granted — ​ $ — ​ Exercised (51) ​ $ 1.01 ​ ​ Forfeited (24) ​ $ 13.41 ​ Outstanding at September 30, 2022 1,424 ​ $ 3.96 7.2 $ 1,260 Exercisable at September 30, 2022 913 ​ $ 4.62 6.9 $ 708 Vested and expected to vest at September 30, 2022 1,424 ​ $ 3.96 7.2 $ 1,260 ​ The Company recognized share-based compensation expense related to stock options of $0.2 million and $0.2 million for the three months ended September 30, 2022 and 2021, respectively, and $0.5 million and $0.6 million for the nine months ended September 30, 2022 and 2021, respectively. As of September 30, 2022, there was $0.7 million of total unrecognized compensation cost related to non-vested stock options which the Company expects to recognize over a weighted-average period of 1.4 years. The total intrinsic value of stock options exercised during the nine months ended September 30, 2022 was $0.1 million. Restricted Stock Units and Performance Restricted Stock Units The following table summarizes the Company’s restricted stock unit and performance restricted stock unit activity for September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-vested ​ Weighted- Non-vested ​ Weighted- ​ ​ Restricted ​ ​ average ​ Performance Restricted ​ ​ average ​ ​ Stock Units ​ ​ Grant-date ​ Stock Units ​ ​ Grant-date ​ ​ (in thousands) ​ ​ Fair Value ​ (in thousands) ​ ​ Fair Value Non-vested at December 31, 2021 ​ 1,729 ​ $ 7.29 395 ​ $ 6.77 Granted 2,775 ​ $ 3.32 — ​ $ — Vested (613) ​ $ 7.64 — ​ $ — Forfeited (226) ​ $ 6.12 — ​ $ — Non-vested at September 30, 2022 3,665 ​ $ 4.29 395 ​ $ 6.77 ​ The Company recognized $2.0 million and $1.8 million in share-based compensation expense related to the restricted stock units and performance restricted stock units for the three months ended September 30, 2022 and 2021, respectively, and $6.1 million and $5.5 million the nine months ended September 30, 2022 and 2021, respectively. As of September 30, 2022, there was $11.0 million of unrecognized compensation cost related to non-vested restricted stock units and performance restricted stock units, which the Company expects to recognize over a weighted-average period of 1.9 years. The total fair value at the vesting date of restricted stock units and performance restricted stock units vested during the nine months ended September 30, 2022, was $2.2 million. The Company did not grant performance restricted stock units during the period ended September 30, 2022. For the period ended December 31, 2021, the grant-date fair value of the performance restricted stock units was estimated at the time of grant using the following inputs and assumptions in the Monte Carlo simulation valuation model: ​ ​ ​ ​ ​ ​ December 31, 2021 Closing price of common stock $ 15.92 ​ Risk-free interest rate ​ 1.15 % Expected volatility ​ 99.7 % ​

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	17. COMMITMENTS AND CONTINGENCIES Legal Matters The Company is subject from time to time to various claims and legal actions arising during the ordinary course of its business. Management believes that there are currently no claims or legal actions that would reasonably be expected to have a material adverse effect on the Company’s results of operations, financial condition, or cash flows.

Geographical Segment Informatio

Geographical Segment Information	9 Months Ended
	Sep. 30, 2022
Segments Geographical Areas [Abstract]
Geographical Segment Information	18. GEOGRAPHICAL SEGMENT INFORMATION Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company currently operates in one business segment as it is managed and operated as one business. A single management team that reports to the chief operating decision maker comprehensively manages the entire business. The Company does not operate any material separate lines of business or separate business entities with respect to its products or product development. The following geographic data includes revenue generated from the Company’s third-party distributors. The Company’s revenue was generated in the following geographic regions and by product line for the periods indicated (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues by Geography ​ ​ Three Months Ended September 30, ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ % of ​ ​ ​ ​ % of ​ ​ Amount ​ Revenues ​ Amount ​ Revenues ​ ​ (in thousands, except percentages) ​ United States $ 16,244 98 % $ 13,280 96 % International ​ 254 2 % 519 4 % Total revenues ​ $ 16,498 100 % $ 13,799 100 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Revenues by Product Category ​ ​ Three Months Ended September 30, ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ % of ​ ​ ​ % of ​ Amount Revenues Amount Revenues ​ (in thousands, except percentages) ​ NeuroStar Advanced Therapy System ​ $ 3,934 ​ 24 % $ 2,612 ​ 20 % Treatment sessions ​ 11,864 73 % 10,259 77 % Other ​ 446 3 % 409 3 % Total U.S. revenues ​ $ 16,244 100 % $ 13,280 100 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ International Revenues by Product Category ​ ​ Three Months Ended September 30, ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ % of ​ ​ ​ ​ % of ​ Amount Revenues Amount Revenues ​ (in thousands, except percentages) ​ NeuroStar Advanced Therapy System ​ $ 96 38 % $ 306 59 % Treatment sessions ​ 31 12 % 90 17 % Other ​ 127 50 % 123 24 % Total International revenues ​ $ 254 100 % $ 519 100 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues by Geography ​ ​ ​ Nine Months Ended September 30, ​ ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ ​ % of ​ ​ ​ ​ % of ​ ​ ​ Amount ​ Revenues ​ Amount ​ Revenues ​ ​ ​ (in thousands, except percentages) ​ ​ United States $ 45,893 98 % $ 38,891 97 % ​ International ​ 1,115 2 % 1,399 3 % ​ Total revenues ​ $ 47,008 100 % $ 40,290 100 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Revenues by Product Category ​ ​ ​ Nine Months Ended September 30, ​ ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ ​ % of ​ ​ ​ % of ​ ​ Amount Revenues Amount Revenues ​ ​ (in thousands, except percentages) ​ ​ NeuroStar Advanced Therapy System ​ $ 11,959 ​ 26 % $ 6,945 ​ 18 % ​ Treatment sessions ​ 32,627 71 % 30,688 79 % ​ Other ​ 1,307 3 % 1,258 3 % ​ Total U.S. revenues ​ $ 45,893 100 % $ 38,891 100 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ International Revenues by Product Category ​ ​ ​ Nine Months Ended September 30, ​ ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ ​ % of ​ ​ ​ ​ % of ​ ​ Amount Revenues Amount Revenues ​ ​ (in thousands, except percentages) ​ ​ NeuroStar Advanced Therapy System ​ $ 460 41 % $ 797 57 % ​ Treatment sessions ​ 214 19 % 235 17 % ​ Other ​ 441 40 % 367 26 % ​ Total International revenues ​ $ 1,115 100 % $ 1,399 100 % ​ ​

Severance

Severance	9 Months Ended
	Sep. 30, 2022
Restructuring And Related Activities [Abstract]
Severance	19. SEVERANCE The Company entered into transition agreements outlining the separation with certain former employees during the period ended September 30, 2022 and 2021. In connection with these agreements, the Company recorded $0.0 million and $0.3 million of charges in salary, payroll tax and bonus expenses for the three months ended September 30, 2022 and 2021, respectively, and $0.2 million and $0.5 million for the nine months ended September 30, 2022 and 2021, respectively. For the nine months ended September 30, 2022 and 2021, $0.4 million and $1.1 million of termination benefits were paid associated with the termination of the employees and charged against this liability. As of September 30, 2022 and December 31, 2021, $0.0 million and $0.1 million, respectively, remain in accrued liabilities for the unpaid portion of the separation benefits.

Risks and Uncertainties

Risks and Uncertainties	9 Months Ended
	Sep. 30, 2022
Risks and Uncertainties [Abstract]
Risks and Uncertainties	20. RISKS AND UNCERTAINTIES Information About Significant Customers ​ Significant customers are those which represent more than 10% of the Company’s total revenue or are considered significant based on combination of quantitative and qualitative factors during the periods. For each significant customer, revenue as a percentage of total revenue was as follows (in thousands, except for percentages): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ % of ​ ​ ​ ​ % of ​ ​ Amount ​ Revenues ​ Amount ​ Revenues ​ ​ (in thousands, except percentages) ​ Customer 1 $ 9,183 20 % $ 8,759 22 % Total ​ $ 9,183 20 % $ 8,759 22 % ​ ​ ​ Accounts receivable outstanding related to these customers as of September 30, 2022 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ ​ 2022 Customer 1 $ 4,886 Total accounts receivable ​ $ 4,886 ​

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Interim Financial Statements	Interim Financial Statements The accompanying unaudited interim financial statements have been prepared from the books and records of the Company in accordance with GAAP for interim financial information and Rule 10-01 of Regulation S-X promulgated by the United States Securities and Exchange Commission, or SEC, which permit reduced disclosures for interim periods. All adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the accompanying balance sheets and statements of operations and stockholders’ equity and cash flows have been made. Although these interim financial statements do not include all of the information and footnotes required for complete annual financial statements, management believes the disclosures are adequate to make the information presented not misleading. Unaudited interim results of operations and cash flows for the three and nine months ended September 30, 2022 are not necessarily indicative of the results that may be expected for the full year. Unaudited interim financial statements and footnotes should be read in conjunction with the audited financial statements and footnotes included in the Company’s Form 10-K filed with the SEC on March 8, 2022, wherein a more complete discussion of significant accounting policies and certain other information can be found.
Use of Estimates	Use of Estimates The preparation of financial statements in accordance with GAAP and the rules and regulations of the SEC requires the use of estimates and assumptions, based on judgments considered reasonable, which affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The Company bases its estimates and assumptions on historical experience, known trends and events and various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Although management believes its estimates and assumptions are reasonable when made, they are based upon information available at the time they are made. Management evaluates the estimates and assumptions on an ongoing basis and, if necessary, makes adjustments. Due to the risks and uncertainties involved in the Company’s business and evolving market conditions, including those related to the COVID-19 pandemic, and given the subjective element of the estimates and assumptions made, actual results may differ materially from estimated results.

Fair Value Measurement and Fi_2

Fair Value Measurement and Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Schedule of Carrying Amounts and Fair Values of Financial Instruments	The following tables set forth the carrying amounts and fair values of the Company’s financial instruments as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement Based on ​ ​ ​ ​ ​ ​ ​ ​ Quoted ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Prices In ​ other ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ Active ​ Observable ​ Unobservable ​ ​ Carrying ​ ​ ​ ​ Markets ​ Inputs ​ Inputs ​ Amount Fair Value (Level 1) (Level 2) (Level 3) Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds (cash equivalents) ​ $ 69,405 ​ $ 69,405 ​ $ 69,405 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement Based on ​ ​ ​ ​ ​ ​ ​ ​ Quoted ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Prices In ​ other ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ Active ​ Observable ​ Unobservable ​ ​ Carrying ​ ​ ​ ​ Markets ​ Inputs ​ Inputs ​ ​ Amount ​ Fair Value ​ (Level 1) ​ (Level 2) ​ (Level 3) Assets ​ ​ ​ ​ ​ Money market funds (cash equivalents) ​ $ 91,236 ​ $ 91,236 ​ $ 91,236 ​ $ — ​ $ —

Accounts Receivable (Tables)

Accounts Receivable (Tables)	9 Months Ended
	Sep. 30, 2022
Receivables [Abstract]
Composition of Accounts Receivable, Net	The following table presents the composition of accounts receivable, net as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2022 2021 Gross accounts receivable - trade ​ $ 13,754 ​ $ 9,168 Less: Allowances for doubtful accounts ​ (1,791) ​ (1,462) Accounts receivable, net ​ $ 11,963 ​ $ 7,706

Property and Equipment and Ca_2

Property and Equipment and Capitalized Software (Tables)	9 Months Ended
	Sep. 30, 2022
Property Plant And Equipment [Abstract]
Summary of Composition of Property and Equipment, Net	The following table presents the composition of property and equipment, net as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2022 2021 ​ Laboratory equipment ​ $ 466 ​ $ 249 ​ Office equipment ​ 508 ​ 497 ​ Computer equipment and software ​ 1,711 ​ 1,598 ​ Manufacturing equipment ​ 344 ​ 341 ​ Leasehold improvements ​ 1,422 ​ 471 ​ Rental equipment ​ 575 ​ 601 ​ Property and equipment, gross ​ 5,026 ​ 3,757 ​ Less: Accumulated depreciation ​ (2,917) ​ (2,537) ​ Property and equipment, net ​ $ 2,109 ​ $ 1,220 ​

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Schedule of Supplemental Cash Flow Information as Lessee Related to Leases	The following table presents the supplemental cash flow information as a lessee related to leases (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ ​ September 30, 2022 September 30, 2021 ​ Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ Operating cash flows from operating leases ​ $ 632 ​ $ 526 ​
Schedule of Future Payments of Operating Lease Liabilities	The following table sets forth by year the required future payments of operating lease liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ September 30, 2022 Remainder of 2022 ​ $ 209 2023 ​ ​ 852 2024 ​ 875 2025 ​ 898 2026 ​ 921 Thereafter ​ 999 Total lease payments ​ 4,754 Less imputed interest ​ (825) Present value of operating lease liabilities ​ $ 3,929
Schedule of Profit Recognized on Sales-type Leases	The following table sets forth the profit recognized on sales-type leases (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ 2022 2021 2022 2021 Profit recognized at commencement, net ​ $ 122 ​ $ 262 ​ $ 543 ​ $ 543 Interest income ​ — ​ — ​ — ​ — Total sales-type lease income ​ $ 122 ​ $ 262 ​ $ 543 ​ $ 543
Schedule of Maturity Analysis of Undiscounted Lease Receivables Related to Sales-type Leases	The following table sets forth a maturity analysis of the undiscounted lease receivables related to sales-type leases (in thousands): ​ ​ ​ ​ ​ ​ September 30, ​ ​ 2022 Remainder of 2022 ​ $ 605 2023 ​ ​ 1,572 2024 ​ 858 2025 ​ 368 2026 ​ ​ 88 Total sales-type lease receivables ​ $ 3,491

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2022
Payables And Accruals [Abstract]
Summary of Composition of Accrued Expenses	The following table presents the composition of accrued expenses as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2022 ​ 2021 Compensation and related benefits ​ $ 8,022 ​ $ 5,090 Consulting and professional fees ​ 760 ​ 537 Research and development expenses ​ 637 ​ 388 Sales and marketing expenses ​ ​ 246 ​ ​ 268 Warranty ​ 337 ​ 306 Sales and other taxes payable ​ 558 ​ 664 Other ​ 933 ​ 980 Accrued expenses ​ $ 11,493 ​ $ 8,233

Deferred Revenue (Tables)

Deferred Revenue (Tables)	9 Months Ended
	Sep. 30, 2022
Deferred Revenue [Abstract]
Summary of Percentages of Deferred Revenue by Year	As of September 30, 2022, the Company expects to recognize approximately the following percentages of deferred revenue by year: ​ ​ ​ ​ ​ ​ Revenue Year: ​ Recognition Remainder of 2022 ​ 25 % 2023 40 % 2024 25 % 2025 8 % 2026 ​ 2 % Total 100 %

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Summary of Composition of Debt	The following table presents the composition of debt as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2022 2021 ​ Outstanding principal ​ $ 35,000 ​ $ 35,000 ​ Accrued final payment fees ​ 1,925 ​ 1,925 ​ Less debt discounts ​ (1,166) ​ (1,590) ​ Total debt, net ​ 35,759 ​ 35,335 ​ Less current portion ​ (8,750) ​ — ​ Long-term debt, net ​ $ 27,009 ​ $ 35,335 ​

Common Stock (Tables)

Common Stock (Tables)	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Summary of Common Stock Issued and Reserved for Issuance	The following table summarizes the total number of shares of the Company’s common stock issued and reserved for issuance as of September 30, 2022 and December 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ September 30, 2022 December 31, 2021 Shares of common stock issued 27,060 26,395 Shares of common stock reserved for issuance for: Common stock warrants outstanding 75 75 Stock options outstanding 1,424 1,499 Restricted stock units outstanding 4,060 2,124 Shares available for grant under stock incentive plan 1,067 2,037 Shares available for sale under employee stock purchase plan 1,063 799 Total shares of common stock issued and reserved for issuance 34,749 32,929
Summary of Outstanding Warrants	The following tables summarize the Company’s outstanding common stock warrants as of September 30, 2022, and December 31, 2021: ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ Warrants ​ Outstanding ​ ​ ​ ​ ​ (in thousands) ​ Exercise Price ​ Expiration Date 14 ​ $ 19.55 Dec-2022 20 ​ $ 9.73 Aug-2023 20 ​ $ 9.73 Mar-2024 21 ​ $ 9.73 Dec-2024 75 ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Warrants ​ Outstanding ​ ​ ​ ​ ​ (in thousands) ​ Exercise Price ​ Expiration Date 14 ​ $ 19.55 Dec-2022 20 ​ $ 9.73 Aug-2023 20 ​ $ 9.73 Mar-2024 21 ​ $ 9.73 Dec-2024 75 ​

Loss Per Share (Tables)

Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Schedule of Potentially Dilutive Securities Outstanding Excluded from Diluted Loss Per Share Calculation	The following potentially dilutive securities outstanding as of September 30, 2022 and 2021 have been excluded from the denominator of the diluted loss per share of common stock outstanding calculation (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ 2022 2021 ​ Stock options ​ 1,424 ​ 1,567 ​ Non-vested performance restricted stock units 395 395 ​ Non-vested restricted stock units 3,665 1,647 ​ Common stock warrants 75 75 ​

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Disclosure Of Compensation Related Costs Share-based Payments [Abstract]
Summary of Share-Based Compensation Expense	The amount of share-based compensation expense recognized by the Company by location in its statements of operations for the three and nine months ended September 30, 2022 and 2021 is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ ​ 2022 2021 2022 2021 ​ Cost of revenues ​ $ 35 ​ $ 23 ​ $ 94 ​ ​ 56 ​ Sales and marketing ​ 1,074 ​ 515 ​ 3,258 ​ ​ 1,608 ​ General and administrative ​ 939 ​ 1,368 ​ 2,950 ​ ​ 4,368 ​ Research and development ​ 130 ​ 55 ​ 331 ​ ​ 134 ​ Total ​ $ 2,178 ​ $ 1,961 ​ $ 6,633 ​ $ 6,166 ​
Summary of Stock Option Activity	The following table summarizes the Company’s stock option activity for the nine months ended September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aggregate ​ ​ Number of ​ Weighted- ​ Weighted- ​ average ​ ​ Shares under ​ average ​ Remaining ​ Intrinsic ​ ​ Option ​ Exercise Price ​ Contractual ​ Value ​ ​ (in thousands) ​ per Option ​ Life (in years) ​ (in thousands) Outstanding at December 31, 2021 1,499 ​ $ 4.01 ​ ​ ​ Granted — ​ $ — ​ Exercised (51) ​ $ 1.01 ​ ​ Forfeited (24) ​ $ 13.41 ​ Outstanding at September 30, 2022 1,424 ​ $ 3.96 7.2 $ 1,260 Exercisable at September 30, 2022 913 ​ $ 4.62 6.9 $ 708 Vested and expected to vest at September 30, 2022 1,424 ​ $ 3.96 7.2 $ 1,260
Summary of Restricted Stock Units and Performance Restricted Stock Units Activity	The following table summarizes the Company’s restricted stock unit and performance restricted stock unit activity for September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-vested ​ Weighted- Non-vested ​ Weighted- ​ ​ Restricted ​ ​ average ​ Performance Restricted ​ ​ average ​ ​ Stock Units ​ ​ Grant-date ​ Stock Units ​ ​ Grant-date ​ ​ (in thousands) ​ ​ Fair Value ​ (in thousands) ​ ​ Fair Value Non-vested at December 31, 2021 ​ 1,729 ​ $ 7.29 395 ​ $ 6.77 Granted 2,775 ​ $ 3.32 — ​ $ — Vested (613) ​ $ 7.64 — ​ $ — Forfeited (226) ​ $ 6.12 — ​ $ — Non-vested at September 30, 2022 3,665 ​ $ 4.29 395 ​ $ 6.77
Summary of Inputs and Assumptions used to Estimated Grant-date Fair Value of Performance Restricted Stock Units	The Company did not grant performance restricted stock units during the period ended September 30, 2022. For the period ended December 31, 2021, the grant-date fair value of the performance restricted stock units was estimated at the time of grant using the following inputs and assumptions in the Monte Carlo simulation valuation model: ​ ​ ​ ​ ​ ​ December 31, 2021 Closing price of common stock $ 15.92 ​ Risk-free interest rate ​ 1.15 % Expected volatility ​ 99.7 %

Geographical Segment Informat_2

Geographical Segment Information (Tables)	9 Months Ended
	Sep. 30, 2022
Summary of Revenue Generated in Geographic Regions for Years Indicated	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues by Geography ​ ​ Three Months Ended September 30, ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ % of ​ ​ ​ ​ % of ​ ​ Amount ​ Revenues ​ Amount ​ Revenues ​ ​ (in thousands, except percentages) ​ United States $ 16,244 98 % $ 13,280 96 % International ​ 254 2 % 519 4 % Total revenues ​ $ 16,498 100 % $ 13,799 100 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues by Geography ​ ​ ​ Nine Months Ended September 30, ​ ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ ​ % of ​ ​ ​ ​ % of ​ ​ ​ Amount ​ Revenues ​ Amount ​ Revenues ​ ​ ​ (in thousands, except percentages) ​ ​ United States $ 45,893 98 % $ 38,891 97 % ​ International ​ 1,115 2 % 1,399 3 % ​ Total revenues ​ $ 47,008 100 % $ 40,290 100 % ​
United States
Summary of Revenue Generated in Product Category for Years Indicated	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Revenues by Product Category ​ ​ Three Months Ended September 30, ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ % of ​ ​ ​ % of ​ Amount Revenues Amount Revenues ​ (in thousands, except percentages) ​ NeuroStar Advanced Therapy System ​ $ 3,934 ​ 24 % $ 2,612 ​ 20 % Treatment sessions ​ 11,864 73 % 10,259 77 % Other ​ 446 3 % 409 3 % Total U.S. revenues ​ $ 16,244 100 % $ 13,280 100 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Revenues by Product Category ​ ​ ​ Nine Months Ended September 30, ​ ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ ​ % of ​ ​ ​ % of ​ ​ Amount Revenues Amount Revenues ​ ​ (in thousands, except percentages) ​ ​ NeuroStar Advanced Therapy System ​ $ 11,959 ​ 26 % $ 6,945 ​ 18 % ​ Treatment sessions ​ 32,627 71 % 30,688 79 % ​ Other ​ 1,307 3 % 1,258 3 % ​ Total U.S. revenues ​ $ 45,893 100 % $ 38,891 100 % ​
International
Summary of Revenue Generated in Product Category for Years Indicated	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ International Revenues by Product Category ​ ​ Three Months Ended September 30, ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ % of ​ ​ ​ ​ % of ​ Amount Revenues Amount Revenues ​ (in thousands, except percentages) ​ NeuroStar Advanced Therapy System ​ $ 96 38 % $ 306 59 % Treatment sessions ​ 31 12 % 90 17 % Other ​ 127 50 % 123 24 % Total International revenues ​ $ 254 100 % $ 519 100 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ International Revenues by Product Category ​ ​ ​ Nine Months Ended September 30, ​ ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ ​ % of ​ ​ ​ ​ % of ​ ​ Amount Revenues Amount Revenues ​ ​ (in thousands, except percentages) ​ ​ NeuroStar Advanced Therapy System ​ $ 460 41 % $ 797 57 % ​ Treatment sessions ​ 214 19 % 235 17 % ​ Other ​ 441 40 % 367 26 % ​ Total International revenues ​ $ 1,115 100 % $ 1,399 100 % ​

Risks and Uncertainties (Tables

Risks and Uncertainties (Tables)	9 Months Ended
	Sep. 30, 2022
Risks and Uncertainties [Abstract]
Schedules of Concentration of Risk by Significant Customers	For each significant customer, revenue as a percentage of total revenue was as follows (in thousands, except for percentages): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ 2022 ​ 2021 ​ ​ ​ ​ ​ % of ​ ​ ​ ​ % of ​ ​ Amount ​ Revenues ​ Amount ​ Revenues ​ ​ (in thousands, except percentages) ​ Customer 1 $ 9,183 20 % $ 8,759 22 % Total ​ $ 9,183 20 % $ 8,759 22 % ​ ​ ​ Accounts receivable outstanding related to these customers as of September 30, 2022 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ ​ 2022 Customer 1 $ 4,886 Total accounts receivable ​ $ 4,886

Description of Business - Addit

Description of Business - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Description Of Business [Line Items]
Cash and cash equivalents	$ 73,698		$ 94,141
Accumulated deficit	337,602		308,733
Cash flows from operating activities	27,639	$ 23,459	$ 28,000
$35.0 Million Credit Facility | Oxford Finance LLC
Description Of Business [Line Items]
Borrowings outstanding under credit facility	$ 35,000
Credit facility maturity date	Feb. 28, 2025

Fair Value Measurement and Fi_3

Fair Value Measurement and Financial Instruments - Schedule of Carrying Amounts and Fair Values of Financial Instruments (Details) - Money market funds - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Carrying Amount
Assets
Total assets	$ 69,405	$ 91,236
Fair Value
Assets
Total assets	69,405	91,236
Quoted Prices In Active Markets (Level 1)
Assets
Total assets	$ 69,405	$ 91,236

Accounts Receivable - Compositi

Accounts Receivable - Composition of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Receivables [Abstract]
Gross accounts receivable - trade	$ 13,754	$ 9,168
Less: Allowances for doubtful accounts	(1,791)	(1,462)
Accounts receivable, net	$ 11,963	$ 7,706

Property and Equipment and Ca_3

Property and Equipment and Capitalized Software - Summary of Composition of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 5,026	$ 3,757
Less: Accumulated depreciation	(2,917)	(2,537)
Property and equipment, net	2,109	1,220
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	466	249
Office Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	508	497
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,711	1,598
Manufacturing Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	344	341
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,422	471
Rental Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	575	601
Property and equipment, net	$ 500	$ 600

Property and Equipment and Ca_4

Property and Equipment and Capitalized Software - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Depreciation and amortization expense	$ 0.4	$ 0.2	$ 1	$ 0.8
Prepaid expenses and other current assets
Property Plant And Equipment [Line Items]
Capitalized software cost, net	$ 3.7		$ 3.7
Other assets
Property Plant And Equipment [Line Items]
Capitalized software cost, net					$ 2.5

Note Receivable (Details)

Note Receivable (Details) - USD ($) $ in Millions			3 Months Ended	9 Months Ended
	Jul. 14, 2022	Sep. 29, 2021	Sep. 30, 2022	Sep. 30, 2022	Apr. 29, 2022
Senior Note | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Payment amount of notes receivable					$ 10
Success T M S
Accounts, Notes, Loans and Financing Receivable [Line Items]
Repayment of notes issued	$ 10.5
Success T M S | Secured Promissory Note
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term of master sales agreement		5 years
Term of notes receivable		5 years
Principal amount of notes receivable		$ 10
Success T M S | Secured Promissory Note | Other income, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income recognized			$ 0.5	$ 1
Success T M S | Secured Promissory Note | Prime Rate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest rate (as a percent)		6%

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) ft²	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) ft²	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Leases [Line Items]
Lessee, finance lease, lease not yet commenced, description			The Company does not currently have any finance leases or executed leases that have not yet commenced.
Operating lease, rent expense, net	$ 200	$ 200	$ 600	$ 400
Operating lease, weighted-average remaining lease term	5 years 3 months 18 days		5 years 3 months 18 days
Operating lease, weighted-average discount rate	7.10%		7.10%
Carrying amount of lease receivables	$ 3,500		$ 3,500
Unguaranteed residual assets	0		0
Operating lease income	70	30	200	200
Property and equipment, net	$ 2,109		$ 2,109		$ 1,220
NeuroStar Advanced Therapy Systems | Minimum
Leases [Line Items]
Lessor sales-type lease, Term	3 years		3 years
NeuroStar Advanced Therapy Systems | Maximum
Leases [Line Items]
Lessor sales-type lease, Term	4 years		4 years
Headquarters and Office Equipment, Including Copiers
Leases [Line Items]
Area of lease facility | ft²	32,000		32,000
Rental Equipment
Leases [Line Items]
Property and equipment, net	$ 500		$ 500		$ 600
Rental equipment depreciation expense	$ 20	$ 10	$ 70	$ 30
Charlotte, North Carolina
Leases [Line Items]
Area of lease facility | ft²	9,600		9,600

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Cash Flow Information as Lessee Related to Leases (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 632	$ 526

Leases - Schedule of Future Pay

Leases - Schedule of Future Payments of Operating Lease Liabilities (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Operating Lease Liabilities Payments Due [Abstract]
Remainder of 2022	$ 209
2023	852
2024	875
2025	898
2026	921
Thereafter	999
Total lease payments	4,754
Less imputed interest	(825)
Present value of operating lease liabilities	$ 3,929

Leases - Schedule of Profit Rec

Leases - Schedule of Profit Recognized on Sales-type Leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Sales Type Lease Lease Income [Abstract]
Profit recognized at commencement, net	$ 122	$ 262	$ 543	$ 543
Total sales-type lease income	$ 122	$ 262	$ 543	$ 543

Leases - Schedule of Maturity A

Leases - Schedule of Maturity Analysis of Undiscounted Lease Receivables Related to Sales-type Leases (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Sales Type And Direct Financing Leases Lease Receivable Fiscal Year Maturity [Abstract]
Remainder of 2022	$ 605
2023	1,572
2024	858
2025	368
2026	88
Total sales-type lease receivables	$ 3,491

Prepaid Commission Expense - Ad

Prepaid Commission Expense - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Amortization Of Deferred Charges [Abstract]
Amortization period of deferred commissions			7 years
Amortization expense	$ 0.5	$ 0.3	$ 1.3	$ 0.9

Accrued Expenses - Summary of C

Accrued Expenses - Summary of Composition of Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Payables And Accruals [Abstract]
Compensation and related benefits	$ 8,022	$ 5,090
Consulting and professional fees	760	537
Research and development expenses	637	388
Sales and marketing expenses	246	268
Warranty	337	306
Sales and other taxes payable	558	664
Other	933	980
Accrued expenses	$ 11,493	$ 8,233

Deferred Revenue - Summary of P

Deferred Revenue - Summary of Percentages of Deferred Revenue by Year (Details)	Sep. 30, 2022
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	100%
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Start Date [Axis]: 2022-10-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	25%
Revenue, remaining performance obligation, expected timing of satisfaction, period	3 months
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Start Date [Axis]: 2023-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	40%
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Start Date [Axis]: 2024-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	25%
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Start Date [Axis]: 2025-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	8%
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Start Date [Axis]: 2026-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	2%
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year

Deferred Revenue - Additional I

Deferred Revenue - Additional Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) customer	Sep. 30, 2021 customer	Sep. 30, 2022 USD ($) customer	Sep. 30, 2021 customer
Deferred Revenue [Abstract]
Revenue recognized | $	$ 0.4		$ 2.2
Number of customer accounted for more than 10% of revenues | customer	1	1	1	1

Debt - Summary of Composition o

Debt - Summary of Composition of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Outstanding principal	$ 35,000	$ 35,000
Accrued final payment fees	1,925	1,925
Less debt discounts	(1,166)	(1,590)
Total debt, net	35,759	35,335
Less current portion	(8,750)
Long-term debt, net	$ 27,009	$ 35,335

Debt - Additional Information (

Debt - Additional Information (Details) $ in Thousands			3 Months Ended		9 Months Ended
	Dec. 08, 2020 USD ($) item	Mar. 02, 2020 USD ($) tranche	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2020 USD ($)	Mar. 31, 2017 USD ($)
Debt Instrument [Line Items]
Interest expense			$ 1,100	$ 1,000	$ 3,000
Cash interest expense			900	800	2,500
Non-cash interest expense			$ 200	$ 200	$ 500
Solar Capital Ltd
Debt Instrument [Line Items]
Amendment fee payable						$ 60	$ 100
Solar Capital Ltd | Term A Loan | Maximum
Debt Instrument [Line Items]
Extended period of interest only term loan	36 months
Solar Capital Ltd | Term A Loan | Minimum
Debt Instrument [Line Items]
Extended period of interest only term loan	24 months
Solar Capital Ltd | Term A Loan and Term B Loan
Debt Instrument [Line Items]
Basis spread on variable rate		1.66%
Interest rate		7.65%
Interest-only period		2022-03
Interest-only period upon achievement of revenues		2023-02
Number of default events		0
Line of credit facility, conversion to term loan, conditions					At the Company’s election, the interest only period may be extended through February 2023 if the Company satisfies a minimum net product revenue covenant through March 1, 2022 and no event of default shall have occurred.
Solar Capital Ltd | $35.0 Million Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity								$ 35,000
Solar Capital Ltd | $35.0 Million Credit Facility | Term A Loan
Debt Instrument [Line Items]
Borrowings outstanding under credit facility		$ 35,000
Solar Capital Ltd | $50.0 Million Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 15,000	$ 50,000
Borrowings outstanding under credit facility	$ 5,000
Term loans number of tranches	3	2
Increase in final payment fees percentage upon extension interest only periods		5.50%
Trailing twelve month net product revenue first threshold limit to pay exit fee		$ 100,000
Trailing twelve month net product revenue Second threshold limit to pay exit fee		$ 125,000
Percentage of exit fee for liquidation, dissolution, winding up or change of control of the Company		4.50%
Percentage of exit fee upon achievement of any trailing twelve month revenues		2.25%
Percentage of exit fee upon achievement of both trailing twelve month revenues		4.50%
Capped exit fee percentage on term loan principal amount		4.50%
Solar Capital Ltd | $50.0 Million Credit Facility | Prepaid on or Before First Anniversary of Funding
Debt Instrument [Line Items]
Prepayment fees percentage		3%
Solar Capital Ltd | $50.0 Million Credit Facility | Prepaid After First and on or Before Second Anniversary of Funding
Debt Instrument [Line Items]
Prepayment fees percentage		2%
Solar Capital Ltd | $50.0 Million Credit Facility | Prepaid After Second Anniversary of Funding
Debt Instrument [Line Items]
Prepayment fees percentage		1%
Solar Capital Ltd | $50.0 Million Credit Facility | Term A Loan
Debt Instrument [Line Items]
Credit facility maturity date		Feb. 28, 2025
Solar Capital Ltd | $15 Million Credit Facility | Term B Loan
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 15,000
Line of credit facility, conversion to term loan, conditions					Under the Term B Loan portion of the Solar Facility, the Company is permitted to borrow, at its election, up to an aggregate amount of $15.0 million, (i) upon the Company achieving a specified amount of trailing twelve months net product revenue, and (ii) assuming there has been no event of default under the Solar Facility prior to such election. Once the net product revenue condition has been satisfied, the Company may make an election to borrow under the Term B Loan portion of the Solar Facility until the earlier of (a) December 15, 2021, (b) 30 days following achievement of the net product revenue condition or (c) the occurrence of an event of default.

Common Stock - Additional Infor

Common Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		9 Months Ended
	Feb. 02, 2021	Sep. 30, 2021
Equity [Abstract]
Common stock shares issued and sold	5,566,000
Public offering price	$ 15.50
Net proceeds from initial public offering	$ 80,600	$ 80,972

Common Stock - Summary of Commo

Common Stock - Summary of Common Stock Issued and Reserved for Issuance (Details) - shares shares in Thousands	Sep. 30, 2022	Dec. 31, 2021
Stockholders Deficit [Line Items]
Shares of common stock issued	27,060	26,395
Shares of common stock reserved for issuance for:
Total shares of common stock issued and reserved for issuance	34,749	32,929
Common stock warrants
Shares of common stock reserved for issuance for:
Shares of common stock reserved for issuance	75	75
Stock options
Shares of common stock reserved for issuance for:
Shares of common stock reserved for issuance	1,424	1,499
Restricted stock units
Shares of common stock reserved for issuance for:
Shares of common stock reserved for issuance	4,060	2,124
Shares available for grant under stock incentive plan
Shares of common stock reserved for issuance for:
Shares of common stock reserved for issuance	1,067	2,037
Shares available for sale under employee stock purchase plan
Shares of common stock reserved for issuance for:
Shares of common stock reserved for issuance	1,063	799

Common Stock - Summary of Outst

Common Stock - Summary of Outstanding Common Stock Warrants (Details) - $ / shares shares in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Class Of Warrant Or Right [Line Items]
Warrants Outstanding	75	75
Exercise Price $19.55
Class Of Warrant Or Right [Line Items]
Warrants Outstanding	14	14
Exercise Price	$ 19.55	$ 19.55
Expiration Date	2022-12	2022-12
Exercise Price $9.73
Class Of Warrant Or Right [Line Items]
Warrants Outstanding	20	20
Exercise Price	$ 9.73	$ 9.73
Expiration Date	2023-08	2023-08
Exercise Price. $9.73
Class Of Warrant Or Right [Line Items]
Warrants Outstanding	20	20
Exercise Price	$ 9.73	$ 9.73
Expiration Date	2024-03	2024-03
Exercise Price $9.73
Class Of Warrant Or Right [Line Items]
Warrants Outstanding	21	21
Exercise Price	$ 9.73	$ 9.73
Expiration Date	2024-12	2024-12

Loss Per Share - Schedule of Po

Loss Per Share - Schedule of Potentially Dilutive Securities Outstanding Excluded from Diluted Loss Per Share Calculation (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities outstanding excluded from diluted loss per share	1,424	1,567
Non-vested performance restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities outstanding excluded from diluted loss per share	395	395
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities outstanding excluded from diluted loss per share	3,665	1,647
Common stock warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities outstanding excluded from diluted loss per share	75	75

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 2,178	$ 1,961	$ 6,633	$ 6,166
Cost of Revenues
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	35	23	94	56
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	1,074	515	3,258	1,608
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	939	1,368	2,950	4,368
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 130	$ 55	$ 331	$ 134

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2022 shares	Sep. 30, 2022 USD ($) shares	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) installment shares	Sep. 30, 2021 USD ($)	Dec. 31, 2020 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expenses		$ 2,178	$ 1,961	$ 6,633	$ 6,166
Intrinsic value of stock options exercised				100
Stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expenses		200	200	500	600
Unrecognized compensation cost related to non-vested stock options		700		$ 700
Non-vested awards not yet recognized weighted-average period for recognition				1 year 4 months 24 days
Restricted Stock Units and Performance Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expenses		2,000	$ 1,800	$ 6,100	$ 5,500
Non-vested awards not yet recognized weighted-average period for recognition				1 year 10 months 24 days
Unrecognized compensation cost related to non-vested restricted stock		$ 11,000		$ 11,000
Fair value of restricted stock vested				$ 2,200
2018 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual percentage increase in number of shares authorized for issuance				4%
Vesting terms of stock options				stock options vest 25% upon the first anniversary of the date of grant and the remainder ratably monthly thereafter for 36 months. Restricted stock units generally vest ratably in three equal installments on the first, second and third anniversaries of the grant date.
Number of vesting installments | installment				3
Shares available for future issuance | shares		600,000		600,000
2018 Equity Incentive Plan | PRSUs | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average price, number of days trailing				30 days
2018 Equity Incentive Plan | First Anniversary of Date of Grant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage of stock options				25%
2018 Equity Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for issuance | shares		1,400,000		1,400,000
Maximum contractual term of stock options				10 years
2020 Inducement Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares authorized for issuance | shares	500,000
Shares available for future issuance | shares		500,000		500,000
2020 Inducement Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for issuance | shares						400,000

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of Stock Option Activity (Details) - Stock options - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares under Option, Outstanding, Beginning balance	1,499
Number of Shares under Option, Exercised	(51)
Number of Shares under Option, Forfeited	(24)
Number of Shares under Option, Outstanding, Ending balance	1,424
Number of Shares under Option, Exercisable	913
Number of Shares under Option, Vested and expected to vest	1,424
Weighted-average Exercise Price per Option, Outstanding, Beginning balance	$ 4.01
Weighted-average Exercise Price per Option, Exercised	1.01
Weighted-average Exercise Price per Option, Forfeited	13.41
Weighted-average Exercise Price per Option, Outstanding, Ending balance	3.96
Weighted-average Exercise Price per Option, Exercisable	4.62
Weighted-average Exercise Price per Option, Vested and expected to vest	$ 3.96
Weighted-average Remaining Contractual Life, Outstanding	7 years 2 months 12 days
Weighted-average Remaining Contractual Life, Exercisable	6 years 10 months 24 days
Weighted-average Remaining Contractual Life, Vested and expected to vest	7 years 2 months 12 days
Aggregate Intrinsic Value, Outstanding	$ 1,260
Aggregate Intrinsic Value, Exercisable	708
Aggregate Intrinsic Value, Vested and expected to vest	$ 1,260

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of Restricted Stock Units and Performance Restricted Stock Unit Activity (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Non-vested, Beginning balance | shares	1,729
Granted | shares	2,775
Vested | shares	(613)
Forfeited | shares	(226)
Non-vested, Ending balance | shares	3,665
Weighted-average Grant-date Fair Value, Non-vested, Beginning balance | $ / shares	$ 7.29
Weighted-average Grant-date Fair Value, Granted | $ / shares	3.32
Weighted-average Grant-date Fair Value, Vested | $ / shares	7.64
Weighted-average Grant-date Fair Value, Forfeited | $ / shares	6.12
Weighted-average Grant-date Fair Value, Non-vested, Ending balance | $ / shares	$ 4.29
Performance Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Non-vested, Beginning balance | shares	395
Non-vested, Ending balance | shares	395
Weighted-average Grant-date Fair Value, Non-vested, Beginning balance | $ / shares	$ 6.77
Weighted-average Grant-date Fair Value, Non-vested, Ending balance | $ / shares	$ 6.77

Share-Based Compensation - Su_4

Share-Based Compensation - Summary of Inputs and Assumptions used to Estimated Grant-date Fair Value of Performance Restricted Stock Unit (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Feb. 02, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Closing price of common stock		$ 15.50
Performance Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Closing price of common stock	$ 15.92
Risk-free interest rate	1.15%
Expected volatility	99.70%

Geographical Segment Informat_3

Geographical Segment Information - Additional Information (Details)	9 Months Ended
	Sep. 30, 2022 segment
Segments Geographical Areas [Abstract]
Number of operating business segment	1

Geographical Segment Informat_4

Geographical Segment Information - Summary of Revenue Generated in Geographic Regions for Years Indicated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Revenues	$ 16,498	$ 13,799	$ 47,008	$ 40,290
Revenue | Geographic Concentration
Segment Reporting Information [Line Items]
Revenues	$ 16,498	$ 13,799	$ 47,008	$ 40,290
Percentage of Revenues	100%	100%	100%	100%
Revenue | United States | Geographic Concentration
Segment Reporting Information [Line Items]
Revenues	$ 16,244	$ 13,280	$ 45,893	$ 38,891
Percentage of Revenues	98%	96%	98%	97%
Revenue | International | Geographic Concentration
Segment Reporting Information [Line Items]
Revenues	$ 254	$ 519	$ 1,115	$ 1,399
Percentage of Revenues	2%	4%	2%	3%

Geographical Segment Informat_5

Geographical Segment Information - Summary of Revenue Generated in Product Category for Years Indicated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Revenues	$ 16,498	$ 13,799	$ 47,008	$ 40,290
Product Category | United States | Revenue
Segment Reporting Information [Line Items]
Revenues	$ 16,244	$ 13,280	$ 45,893	$ 38,891
Percentage of Revenues	100%	100%	100%	100%
Product Category | United States | Revenue | NeuroStar Advanced Therapy System
Segment Reporting Information [Line Items]
Revenues	$ 3,934	$ 2,612	$ 11,959	$ 6,945
Percentage of Revenues	24%	20%	26%	18%
Product Category | United States | Revenue | Treatment Sessions
Segment Reporting Information [Line Items]
Revenues	$ 11,864	$ 10,259	$ 32,627	$ 30,688
Percentage of Revenues	73%	77%	71%	79%
Product Category | United States | Revenue | Other
Segment Reporting Information [Line Items]
Revenues	$ 446	$ 409	$ 1,307	$ 1,258
Percentage of Revenues	3%	3%	3%	3%
Product Category | International | Revenue
Segment Reporting Information [Line Items]
Revenues	$ 254	$ 519	$ 1,115	$ 1,399
Percentage of Revenues	100%	100%	100%	100%
Product Category | International | Revenue | NeuroStar Advanced Therapy System
Segment Reporting Information [Line Items]
Revenues	$ 96	$ 306	$ 460	$ 797
Percentage of Revenues	38%	59%	41%	57%
Product Category | International | Revenue | Treatment Sessions
Segment Reporting Information [Line Items]
Revenues	$ 31	$ 90	$ 214	$ 235
Percentage of Revenues	12%	17%	19%	17%
Product Category | International | Revenue | Other
Segment Reporting Information [Line Items]
Revenues	$ 127	$ 123	$ 441	$ 367
Percentage of Revenues	50%	24%	40%	26%

Severance - Additional Informat

Severance - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Restructuring Cost And Reserve [Line Items]
Accrued liabilities	$ 11,493		$ 11,493		$ 8,233
Transition Separation Agreement
Restructuring Cost And Reserve [Line Items]
Restructuring charges	0	$ 300	200	$ 500
Accrued liabilities	$ 0		0		$ 100
Termination Benefits | Transition Separation Agreement
Restructuring Cost And Reserve [Line Items]
Payments for restructuring			$ 400	$ 1,100

Risks and Uncertainties - Infor

Risks and Uncertainties - Information About Significant Customers (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Concentration Risk [Line Items]
Accounts receivable	$ 11,963		$ 7,706
Significant Customers
Concentration Risk [Line Items]
Accounts receivable	4,886
Customer 1
Concentration Risk [Line Items]
Accounts receivable	4,886
Revenue | Customer concentration risk | Significant Customers
Concentration Risk [Line Items]
Revenues	$ 9,183	$ 8,759
Concentration of risk (as a percent)	20%	22%
Revenue | Customer concentration risk | Customer 1
Concentration Risk [Line Items]
Revenues	$ 9,183	$ 8,759
Concentration of risk (as a percent)	20%	22%