Sage Therapeutics (SAGE) S-8 Registration of securities for employees

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement onForm S-8 of our reportdated February 22, 2018 relating to the financial statements, and the effectiveness of internal control over financial reporting, which appears in Sage Therapeutics, Inc.’s Annual Report on Form10-K for the year ended December 31, 2017.

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts

November 6, 2018