SecProbe.io

Mail Stop 4720
December 15, 2009
 Uli Hacksell, Ph.D.  Chief Executive Officer  ACADIA Pharmaceuticals Inc.  3911 Sorrento Valley Boulevard San Diego, CA 92121
Re: ACADIA Pharmaceuticals Inc.
 Form 10-K for the year ended 12/31/2008
Filed March 10, 2009
 File No. 000-50768

Dear Dr. Hacksell:

We have reviewed your filing and have the following comments.  Where the comments
request you to revise disclosure, the informati on you provide should show us what the revised
disclosure will look like and identify the annual or quarterly filing, as applicable, in which you
intend to first include it.  If you do not believe that revised disc losure is necessary, explain the
reason in your response.  After reviewing the information provided, we may raise additional
comments and/or request that you amend your filing.
  Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure requir ements and to enhance the overall disclosure in
your filing.  We look forward to working with you in these respects.  We welcome any questions
you may have about our comment or on any other aspect  of our review.  Feel free to call us at the
telephone numbers listed at th e end of this  letter.
 Form 10-K

 Collaboration Agreements, page 11

1. Please advise us whether your July 2002 agr eement with Aventis remains in effect and
whether you have received payments from Av entis (now Sanofi-Aventis) within the last
year or may be entitled to rece ive payments in the future under this agreement.  Please
file this agreement as an exhibit or provide your analysis why such filing is not required
by Item 601(b)(10) of Regulation S-K.

Uli Hacksell, Ph.D.
ACADIA Pharmaceuticals Inc.
December 15, 2009
Page 2 of 3
 Intellectual Property, page 12

2. To the extent not in conflict with the grant of confidential treatment for portions of the
agreement, please describe all of the material terms of your November 30, 2006
agreement with the Ipsen Group.

3. Please expand your disclosure here to include  the expiration dates for your material
patents, or a range of expiration dates for each group of patents you associate with each
of your material product candidates.
 Schedule 14A

 Compensation Discussion and Analysis

2008 Annual Incentive Bonuses, page 20

4. Notwithstanding the Compensation Committee’ s decision to pay no annual incentive
bonuses for 2008, please be advised that if pe rformance goals were established for your
named executive officers you are required to disclose in your Co mpensation Discussion
and Analysis the specific goals and the degree of  attainment of those goals.  Therefore, if
goals have been established by the Compensation Committee for 2009, you should be prepared to discuss these in  your next proxy statement.  As such please provide draft
disclosure for your 2010 proxy statement discu ssion of the detailed set of individual and
corporate performance goals for each name d executive officer.  In addition, please
confirm that in your next proxy statement you will disclose the extent to which each
officer’s performance met, exceeded or fell s hort of the goal(s) and how his or her level
of performance related to the bonus ultimately awarded.  To the extent that pre-
established goals and the executi ve’s level of performance ar e quantifiable, the discussion
in your proxy statement shoul d also be quantified.

* * *

Please respond to these comments within 10 business days or tell us when you will
provide us with responses.  Please furnish a letter that keys your response to our comments and
provide the requested information.  Detailed letters greatly facili tate our review.  Please furnish
your letter on EDGAR under the form type label CORRESP.
  We urge all persons who are responsible for th e accuracy and adequacy of the disclosure
in the filing to be certain that the filing in cludes all information re quired under the Securities
Exchange Act of 1934 and that they have provi ded all information investors require for an
informed investment decision.  Since the compa ny and its management are in possession of all
facts relating to a company’s disclosure, they are responsible for the acc uracy and adequacy of
the disclosures they have made.

Uli Hacksell, Ph.D.
ACADIA Pharmaceuticals Inc.
December 15, 2009
Page 3 of 3
  In connection with responding to our co mments, please provide, in your letter, a
statement from the company acknowledging that:
• the company is responsible for the adequacy an d accuracy of the disclo sure in the filing;
• staff comments or changes to disclosure in response to staff comments do not foreclose
the Commission from taking any action with respect to the filing; and
• the company may not assert staff comments as  a defense in any proceeding initiated by
the Commission or any person under the federa l securities laws of  the United States.

In addition, please be advise d that the Division of Enfo rcement has access to all
information you provide to the sta ff of the Division of Corporati on Finance in our review of your
filing or in response to our comment on your filing.
Please contact Michael Rosent hall at (202) 551-3674 or me  at (202) 551-3715 with any
questions.
Sincerely,
           J e f f r e y  P .  R i e d l e r          A s s i s t a n t  D i r e c t o r    cc: D. Bradley Peck
J. Patrick Loofbourrow Cooley Godward Kronish LLP 4401 Eastgate Mall San Diego, CA 92121 Fax: 858-550-6420