<SEC-DOCUMENT>0001144204-13-003641.txt : 20130123
<SEC-HEADER>0001144204-13-003641.hdr.sgml : 20130123
<ACCEPTANCE-DATETIME>20130123164831
ACCESSION NUMBER:		0001144204-13-003641
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20130118
FILED AS OF DATE:		20130123
DATE AS OF CHANGE:		20130123

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ACADIA PHARMACEUTICALS INC
		CENTRAL INDEX KEY:			0001070494
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				061376651
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3911 SORRENTO VALLEY BLVD
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
		BUSINESS PHONE:		858-558-2871

	MAIL ADDRESS:	
		STREET 1:		3911 SORRENTO VALLEY BLVD
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BAKER JULIAN
		CENTRAL INDEX KEY:			0001087939

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50768
		FILM NUMBER:		13543241

	MAIL ADDRESS:	
		STREET 1:		BAKER BROTHERS ADVISORS
		STREET 2:		667 MADISON AVENUE, 21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BAKER FELIX
		CENTRAL INDEX KEY:			0001087940

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50768
		FILM NUMBER:		13543242

	MAIL ADDRESS:	
		STREET 1:		BAKER BROTHERS ADVISORS
		STREET 2:		667 MADISON AVENUE, 21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BAKER BROS ADVISORS LLC
		CENTRAL INDEX KEY:			0001263508
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50768
		FILM NUMBER:		13543240

	BUSINESS ADDRESS:	
		STREET 1:		667 MADISON AVE
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065
		BUSINESS PHONE:		2123395600

	MAIL ADDRESS:	
		STREET 1:		667 MADISON AVE
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Baker Brothers Life Sciences LP
		CENTRAL INDEX KEY:			0001363364
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50768
		FILM NUMBER:		13543237

	BUSINESS ADDRESS:	
		STREET 1:		667 MADISON AVENUE
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065
		BUSINESS PHONE:		212-339-5633

	MAIL ADDRESS:	
		STREET 1:		667 MADISON AVENUE
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			14159, L.P.
		CENTRAL INDEX KEY:			0001551138
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50768
		FILM NUMBER:		13543238

	BUSINESS ADDRESS:	
		STREET 1:		667 MADISON AVE.
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065
		BUSINESS PHONE:		212-339-5600

	MAIL ADDRESS:	
		STREET 1:		667 MADISON AVE.
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			667, L.P.
		CENTRAL INDEX KEY:			0001551139
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50768
		FILM NUMBER:		13543239

	BUSINESS ADDRESS:	
		STREET 1:		667 MADISON AVE.
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065
		BUSINESS PHONE:		212-339-5600

	MAIL ADDRESS:	
		STREET 1:		667 MADISON AVE.
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form456702_20130123044703-.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-01-18</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001070494</issuerCik>
        <issuerName>ACADIA PHARMACEUTICALS INC</issuerName>
        <issuerTradingSymbol>ACAD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001087940</rptOwnerCik>
            <rptOwnerName>BAKER FELIX</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>667 MADISON AVENUE, 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>US 10065</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001087939</rptOwnerCik>
            <rptOwnerName>BAKER JULIAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>667 MADISON AVENUE, 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>US 10065</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001263508</rptOwnerCik>
            <rptOwnerName>BAKER BROS ADVISORS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>667 MADISON AVENUE, 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>US 10065</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001551139</rptOwnerCik>
            <rptOwnerName>667, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>667 MADISON AVENUE 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>US 10065</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001551138</rptOwnerCik>
            <rptOwnerName>14159, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>667 MADISION AVENUE, 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>US 10065</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001363364</rptOwnerCik>
            <rptOwnerName>Baker Brothers Life Sciences LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>667 MADISON AVENUE, 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>US 10065</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.22</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2013-01-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>15000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2023-01-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>15000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On January 18, 2013, Dr. Stephen R. Biggar was elected to ACADIA Pharmaceuticals Inc.'s (the &quot;Issuer&quot;) Board of Directors (the &quot;Board&quot;). Upon his appointment to the Board, Dr. Biggar was granted options to purchase 15,000 shares of the Issuer's common stock at $5.22 per share expiring 10 years from the date of the grant (the &quot;Options&quot;). The Options vest in equal tranches on January 18, 2014 and January 18, 2015. Dr. Biggar serves on the Issuer's Board as a representative of Baker Brothers Life Sciences, L.P., (&quot;Life Sciences&quot;), 667, L.P. (&quot;667&quot;), and 14159, L.P. (&quot;14159&quot; and together with Life Sciences and 667, the &quot;Funds&quot;). Due to the agreements and policies of the Funds and Dr. Biggar's agreement to follow those agreements and policies, Dr. Biggar does not have any right to receive pecuniary interest in securities as compensation for serving as a director of the Issuer and therefore has no pecuniary interest in the Options. Dr. Biggar, however, retains the right to vote and dispose of any shares of common stock underlying the Options. The Funds are entitled to pecuniary interest in the Options and each holds an indirect proportionate pecuniary interest. Felix J. Baker and Julian C. Baker, solely as a result of their ownership interest in the general partner of the general partners of the Funds, may be deemed to have an indirect proportionate pecuniary interest in the Options (ie. no direct pecuniary interest).</footnote>
        <footnote id="F2">Baker Bros. Advisors, LLC (the &quot;Adviser&quot;) serves as the Investment Adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held by the Funds. Julian C. Baker and Felix J. Baker are principals of the Adviser. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held by the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held by the Funds. Julian C. Baker, Felix J. Baker and the Adviser disclaim beneficial ownership of the securities held directly by the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.</footnote>
    </footnotes>

    <remarks>Dr. Stephen R. Biggar is a Partner of Baker Bros. Advisors LLC and a director of ACADIA Pharmaceuticals, Inc. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, the reporting persons are deemed directors by deputization by virtue of their representation on the Board of Directors of ACADIA Pharmaceuticals. Inc.</remarks>

    <ownerSignature>
        <signatureName>/s/ Felix J. Baker</signatureName>
        <signatureDate>2013-01-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Julian C. Baker</signatureName>
        <signatureDate>2013-01-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Title: President /s/ Scott L. Lessing</signatureName>
        <signatureDate>2013-01-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Baker Bros. Advisors, LLC, Mgmt. Co. and Inv. Adviser to 667, L.P., pursuant to authority granted by Baker Biotech Capital, L.P., GP to 667, L.P. Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing</signatureName>
        <signatureDate>2013-01-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Baker Bros. Advisors, LLC, Mgmt. Co. and Inv. Adviser to 14159, L.P., pursuant to authority granted by 14159 Capital, L.P., GP to 14159, L.P. Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing</signatureName>
        <signatureDate>2013-01-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</SEC-DOCUMENT>
