| Document And Entity Information | Mar. 25, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Amendment Flag | true |
| Document Period End Date | Mar. 25, 2022 |
| Entity Registrant Name | Axsome Therapeutics, Inc. |
| Entity Central Index Key | 0001579428 |
| Entity Emerging Growth Company | false |
| Entity File Number | 001-37635 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 45-4241907 |
| Entity Address, Address Line One | 22 Cortlandt Street, 16th Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10007 |
| City Area Code | (212) |
| Local Phone Number | 332-3241 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, Par Value $0.0001 Per Share |
| Trading Symbol | AXSM |
| Security Exchange Name | NASDAQ |
| Amendment Description | This Current Report on Form 8-K/A (this “Amendment No. 1”) is being filed to amend the Current Report on Form 8-K filed by Axsome Therapeutics, Inc. March 28, 2022 (the “Initial Form 8-K”) for the sole purpose of adding as an exhibit the Asset Purchase Agreement with Jazz Pharmaceuticals plc (the “Purchase Agreement”), referred to in the Initial Form 8-K. Item 1.01 Entry into a Material Definitive Agreement. |
