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        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001365619</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001070494</issuerCik>
            <issuerName>ACADIA PHARMACEUTICALS INC.</issuerName>
            <secFileNumber>000-50768</secFileNumber>
            <issuerAddress>
                <ns2:street1>12830 El Camino Real, Suite 400</ns2:street1>
                <ns2:city>San Diego</ns2:city>
                <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                <ns2:zipCode>92130</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>(858) 558-2871</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>LAURA BREGE</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Director</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>14446</noOfUnitsSold>
            <aggregateMarketValue>314638.21</aggregateMarketValue>
            <noOfUnitsOutstanding>167361851</noOfUnitsOutstanding>
            <approxSaleDate>06/04/2025</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/07/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>2000</amountOfSecuritiesAcquired>
            <paymentDate>06/07/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/22/2021</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>3059</amountOfSecuritiesAcquired>
            <paymentDate>06/22/2021</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>05/29/2025</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>9387</amountOfSecuritiesAcquired>
            <paymentDate>05/29/2025</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>06/04/2025</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ Laura Ann Brege</signature>
        </noticeSignature>
    </formData>
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144
0001365619
XXXXXXXX
LIVE
0001070494
ACADIA PHARMACEUTICALS INC.
000-50768
12830 El Camino Real, Suite 400
San Diego
CA
92130
(858) 558-2871
LAURA BREGE
Director
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
14446
314638.21
167361851
06/04/2025
NASDAQ
Common
06/07/2022
Restricted Stock
Issuer
N
2000
06/07/2022
Not Applicable
Common
06/22/2021
Restricted Stock
Issuer
N
3059
06/22/2021
Not Applicable
Common
05/29/2025
Restricted Stock
Issuer
N
9387
05/29/2025
Not Applicable
Y
06/04/2025
/s/ Laura Ann Brege