United States securities and exchange commission logo September 1, 2020 Kimi Igluchi Chief Financial Officer Sage Therapeutics, Inc. 215 First Street Cambridge, MA 02142 Re: Sage Therapeutics, Inc. Form 10-K for the Fiscal Year Ended December 31, 2019 Filed February 27, 2020 File No. 001-36544 Dear Ms. Igluchi: We have completed our review of your filing. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Sincerely, Division of Corporation Finance Office of Life Sciences