POWER OF ATTORNEY


      I, the undersigned, hereby authorize and designate Anne Marie
Cook (SVP, General Counsel), Kimi Iguchi (Chief Financial Officer)
and Jennifer Fitzpatrick (VP, Corporate Counsel), for as long as they
remain employees of Sage Therapeutics, Inc., and Stuart Falber of
WilmerHale, each acting singly, or their successors in role, to take
the following actions, acting as my agent and attorney-in-fact, with
full power of substitution:

          (1)  to prepare and sign on my behalf any Form 4 or Form 5
pursuant to Section 16 of the Securities Exchange Act of 1934, as
amended, and to file the same with the Securities and Exchange
Commission, NASDAQ, NYSE, and each stock exchange on which shares of
Common Stock or other securities of Sage Therapeutics, Inc. are
listed, as required by law;

          (2)  to prepare and sign on my behalf any Form 144
pursuant to the Securities Act of 1933, as amended, and to file the
same with the Securities and Exchange Commission, NASDAQ, NYSE, and
each stock exchange on which shares of Common Stock or other
securities of Sage Therapeutics, Inc. are listed, as required by law;
and

          (3)  take any other action necessary or proper in
connection with the foregoing.

      Unless earlier revoked under the next sentence, this Power of
Attorney shall remain in effect as long as I am a director or
executive officer of Sage Therapeutics, Inc., and shall not be
affected by my subsequent disability or incompetence.  I may revoke
this Power of Attorney by written notice delivered, in person or by
nationally recognized courier, to the attention of the SVP, General
Counsel of Sage Therapeutics, Inc.

/s/ Barry Greene
Name: 	Barry Greene
Date:  	October 1, 2020