Acadia Pharmaceuticals, Inc.

3911 Sorrento Valley Boulevard
San Diego, California 92121

This Schedule 13G is being filed jointly by Felix J. Baker and Julian C. Baker (the “Reporting Persons”).

Each of the Reporting Persons is a United States citizen.

 Common Stock, par value $0.0001 per share

004225108

(a) [ ] Broker or dealer registered under Section 15 of the Exchange Act.

(b) [ ] Bank as defined in section 3(a)(6) of the Exchange Act.

(c) [ ] Insurance company as defined in section 3(a)(19) of the Exchange Act.

(d) [ ] Investment company registered under section 8 of the Investment Company Act of 1940.

(e) [ ] An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E).

(f) [ ] An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F).

(g) [ ] A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G).

(h) [ ] A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act.

(i) [ ] A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940.

(j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

Set forth below is the aggregate number of shares of Common Stock held, including shares that maybe acquired upon the exercise of Warrants as of the date hereof by each of the following, together with the percentage of outstanding shares of Common Stock that such number represents based upon 52,800,919 shares outstanding, as reported on the Company’s SEC Form 10Q filed on November 9, 2011. Such percentage figures are calculated on the basis that the Warrants owned by the Reporting Persons are deemed converted into or exercised for shares of Common Stock but other outstanding Warrants are not deemed converted or exercised.

The Warrants are only exercisable to the extent that the holders thereof and their affiliates would beneficially own, for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, no more than 9.9% of the outstanding shares of Common Stock of the Issuer after exercise. As a result of this restriction, the number of shares that may be issued on exercise of the Warrants by the above holders may change depending upon changes in the outstanding shares. The number of shares issuable upon exercise of the Warrants held by any particular Baker Bros. affiliate will also depend upon the extent to which the Warrants held by other Baker Bros. affiliates have theretofore been exercised.

By virtue of their ownership of entities that have the power to control the investment decisions of the limited partnerships listed in the table above, Felix J. Baker and Julian C. Baker may each be deemed to be beneficial owners of shares owned by such entities and may be deemed to have shared power to vote or direct the vote of and shared power to dispose or direct the disposition of such securities.

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following [ ].

The entities listed in Item 4 above are investment funds the investors in which have the right to receive dividends, interest and the proceeds of sale of securities owned by such funds.

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By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I hereby certify that the information set forth in this statement is true, complete and correct.

February 14, 2012

AGREEMENT

In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree that this Statement on Schedule 13G relating to the Common Stock of Acadia Pharmaceuticals, Inc. is being filed with the Securities and Exchange Commission on behalf of each of them.

February 14, 2012