<SEC-DOCUMENT>0001415889-18-000158.txt : 20180131
<SEC-HEADER>0001415889-18-000158.hdr.sgml : 20180131
<ACCEPTANCE-DATETIME>20180131175617
ACCESSION NUMBER:		0001415889-18-000158
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180129
FILED AS OF DATE:		20180131
DATE AS OF CHANGE:		20180131

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Baity Glenn
		CENTRAL INDEX KEY:			0001487100

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50768
		FILM NUMBER:		18564010

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

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:		3611 VALLEY CENTRE DRIVE
		STREET 2:		SUITE 300
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92130
		BUSINESS PHONE:		858-558-2871

	MAIL ADDRESS:	
		STREET 1:		3611 VALLEY CENTRE DRIVE
		STREET 2:		SUITE 300
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92130
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4-01312018_020102.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-01-29</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001487100</rptOwnerCik>
            <rptOwnerName>Baity Glenn</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3611 VALLEY CENTRE DRIVE, SUITE 300</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>EVP AND GC</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-01-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>36558</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>32.3884</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>83734</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in May 2017 and amended in November 2017.</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $32.37 to $32.45 per share, inclusive.The reporting person undertakes to provide ACADIA Pharmaceuticals Inc., any security holder of ACADIA Pharmaceuticals Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the foregoing range.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Glenn F. Baity</signatureName>
        <signatureDate>2018-01-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
