<SUBMISSION>
<ACCESSION-NUMBER>0001193125-04-095536
<TYPE>S-8
<PUBLIC-DOCUMENT-COUNT>4
<FILING-DATE>20040527
<EFFECTIVENESS-DATE>20040527
<FILER>
<COMPANY-DATA>
<CONFORMED-NAME>ACADIA PHARMACEUTICALS INC
<CIK>0001070494
<ASSIGNED-SIC>2834
<IRS-NUMBER>061376651
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>S-8
<ACT>33
<FILE-NUMBER>333-115956
<FILM-NUMBER>04835971
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>3911 SORRENTO VALLEY BLVD
<CITY>SAN DIEGO
<STATE>CA
<ZIP>92121
<PHONE>858-558-2871
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>3911 SORRENTO VALLEY BLVD
<CITY>SAN DIEGO
<STATE>CA
<ZIP>92121
</MAIL-ADDRESS>
</FILER>
<DOCUMENT>
<TYPE>S-8
<SEQUENCE>1
<FILENAME>ds8.htm
<DESCRIPTION>FORM S-8
<TEXT>
<HTML><HEAD>
<TITLE>Form S-8</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>As filed with the Securities and Exchange Commission on May <U></U>27, 2004 </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>Registration No. <U>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U>
</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="3" NOSHADE COLOR="#000000" ALIGN="left"> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>UNITED STATES </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>SECURITIES AND
EXCHANGE COMMISSION </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>Washington, D.C. 20549 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT
SIZE="1">&nbsp;</FONT></P><HR WIDTH="17%" SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="5"><B>FORM S-8 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>REGISTRATION STATEMENT </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="3"><B>UNDER </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>THE SECURITIES ACT OF 1933 </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P><HR WIDTH="17%" SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="6"><B>ACADIA PHARMACEUTICALS INC. </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Exact Name of Registrant as Specified in Its
Charter) </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P><HR WIDTH="17%" SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="49%"></TD>
<TD VALIGN="bottom" WIDTH="3%"></TD>
<TD WIDTH="48%"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Delaware</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>06-1376651</B></FONT></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(State or Other Jurisdiction of</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Incorporation or Organization)</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(I.R.S. Employer</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Identification No.)</B></FONT></P></TD></TR>
</TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>3911 Sorrento Valley
Boulevard </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>San Diego, CA 92121 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="2"><B>(858) 558-2871 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Address of Principal Executive Offices) </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P><HR WIDTH="17%" SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>ACADIA Pharmaceuticals Inc. </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>1997 S<SMALL>TOCK</SMALL> O<SMALL>PTION</SMALL>
P<SMALL>LAN</SMALL> </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>2004 E<SMALL>QUITY</SMALL> I<SMALL>NCENTIVE</SMALL> P<SMALL>LAN</SMALL> </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>2004 E<SMALL>MPLOYEE</SMALL> S<SMALL>TOCK</SMALL> P<SMALL>URCHASE</SMALL> P<SMALL>LAN</SMALL> </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Full Title of the Plans) </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P><HR WIDTH="17%" SIZE="1" NOSHADE
COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Uli Hacksell, Ph.D. </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Chief Executive Officer </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>ACADIA
Pharmaceuticals Inc. </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>3911 Sorrento Valley Boulevard </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2"><B>San Diego, CA 92121 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Name and Address of Agent for Service) </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>(858) 558-2871 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Telephone Number, Including Area Code, of Agent for Service) </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P><HR WIDTH="17%" SIZE="1" NOSHADE
COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Copies to: </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>D. Bradley Peck, Esq. </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Glenn F. Baity, Esq. </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="2"><B>C<SMALL>OOLEY</SMALL> G<SMALL>ODWARD</SMALL> <SMALL>LLP</SMALL> </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>4401 Eastgate Mall </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>San Diego, CA 92121 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>(858) 550-6000
</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P><HR WIDTH="17%" SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>CALCULATION OF REGISTRATION FEE </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT
SIZE="1">&nbsp;</FONT></P><HR SIZE="3" NOSHADE COLOR="#000000" ALIGN="left">
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="44%"></TD>
<TD VALIGN="bottom" WIDTH="9%"></TD>
<TD WIDTH="10%"></TD>
<TD WIDTH="1%"></TD>
<TD VALIGN="bottom" WIDTH="8%"></TD>
<TD WIDTH="1%"></TD>
<TD></TD>
<TD WIDTH="1%"></TD>
<TD VALIGN="bottom" WIDTH="8%"></TD>
<TD WIDTH="1%"></TD>
<TD WIDTH="4%"></TD>
<TD WIDTH="1%"></TD>
<TD VALIGN="bottom" WIDTH="8%"></TD>
<TD WIDTH="1%"></TD>
<TD WIDTH="3%"></TD></TR>
<TR>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Title of Each Class of</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Securities to be Registered</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Amount</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="1"><B>to be</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Registered(1)</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Proposed<BR>Maximum</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Offering&nbsp;Price<BR>per Share</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" COLSPAN="2" NOWRAP ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Proposed<BR>Maximum</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Aggregate</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Offering Price</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Amount of</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Registration<BR>Fee</B></FONT></P></TD></TR>
<TR>
<TD VALIGN="bottom" COLSPAN="15"><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Common Stock issuable under the 1997 Stock Option Plan (par value $0.0001 per share)</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD ALIGN="right" COLSPAN="1" VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">2,413,823&nbsp;shares&nbsp;</FONT></TD>
<TD COLSPAN="1" NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">(2)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">&nbsp;(2)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">8,653,926</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">(2)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">1,097</FONT></TD></TR>
<TR>
<TD VALIGN="bottom" COLSPAN="15"><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Common Stock issuable under the 2004 Equity Incentive Plan (par value $0.0001 per share)</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD ALIGN="right" COLSPAN="1" VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">200,000&nbsp;shares&nbsp;</FONT></TD>
<TD COLSPAN="1" NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">(3)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">7.00&nbsp;</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">(4)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">1,400,000</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">(4)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">177</FONT></TD></TR>
<TR>
<TD VALIGN="bottom" COLSPAN="15"><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Common Stock issuable under the 2004 Employee Stock Purchase Plan (par value $0.0001 per share)</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD ALIGN="right" COLSPAN="1" VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">125,000&nbsp;shares&nbsp;</FONT></TD>
<TD COLSPAN="1" NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">(5)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">7.00&nbsp;</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">(4)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">875,000</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">(4)</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">$<U></U></FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><U></U>111</FONT></TD></TR>
<TR>
<TD VALIGN="bottom" COLSPAN="15"><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Total</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD ALIGN="right" COLSPAN="1" VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">2,738,823 shares</FONT></TD>
<TD COLSPAN="1" NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">N/A</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">$</FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">10,928,926</FONT></TD>
<TD NOWRAP VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">$<U></U></FONT></TD>
<TD VALIGN="bottom" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><U></U>1,385</FONT></TD></TR>
</TABLE><HR SIZE="3" NOSHADE COLOR="#000000" ALIGN="left">
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Pursuant to Rule 416(a) under the Securities Act of 1933, as amended (the &#147;1933 Act&#148;), this Registration Statement also registers any additional shares of the
Registrant&#146;s common stock, par value $0.0001 per share (the &#147;Common Stock&#148;), as may become issuable under any of the plans as a result of any stock split, stock dividend, recapitalization or similar event. </FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(2)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Estimated solely for purposes of calculating the registration fee pursuant to Rule 457(h) of the 1933 Act. The Proposed Maximum Offering Price Per Share and the Proposed Maximum
Aggregate Offering Price for the 1,668,590 shares of Common Stock reserved for issuance upon the exercise of outstanding options under the 1997 Stock Option Plan, as amended (the &#147;1997 Plan&#148;) are calculated using a weighted average
exercise price for such shares of $2.06 per share. The Proposed Maximum Offering Price Per Share and the Proposed Maximum Aggregate Offering Price for the 745,233 shares of Common Stock available for future grant under the 1997 Plan are calculated
using the price per share in the initial public offering (the &#147;Offering&#148;) of the Registrant&#146;s Common Stock as set forth in the Registrant&#146;s Prospectus filed with the Securities and Exchange Commission on May 27, 2004 pursuant to
Rule 424(b) under the 1933 Act. The maximum term of options granted under the 1997 Plan is ten years. No options will be granted under the 1997 Plan following the closing of the Offering. Any shares of Common Stock reserved for issuance upon the
exercise of outstanding options under the 1997 Plan that are terminated or expire unexercised will reduce the share reserve under the 1997 Plan but will increase the share reserve under the 2004 EIP by the same amount as the reduction in the 1997
Plan share reserve. </FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(3)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Represents 200,000 shares of Common Stock initially available for future grants under the 2004 Equity Incentive Plan (the &#147;2004 EIP&#148;) and up to an additional number of
shares that may become issuable under the 2004 EIP pursuant to its terms. The 2004 EIP provides that the share reserve shall be increased by the number of shares of common stock that remain authorized for issuance under the 1997 Plan as of the
closing of the Offering and any shares that may thereafter revert to the 1997 Plan share reserve. The 2004 EIP provides that an additional number of shares will automatically be added annually for a period of five years to the shares authorized for
issuance under the 2004 EIP at each annual meeting of stockholders beginning in 2005. The number of shares added each year will be equal to the least of: three percent of the Company&#146;s outstanding Common Stock as of the record date for the
applicable annual meeting; 750,000 shares of Common Stock, or; an amount that may be determined each year by the Company&#146;s board of directors. No shares of Common Stock are currently reserved for issuance upon the exercise of options
outstanding under the 2004 EIP because no options have yet been granted under the 2004 EIP. </FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">2. </FONT></P>


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<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">


<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(4)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">This estimate is made pursuant to Rule 457(h) of the 1933 Act solely for purposes of calculating the registration fee, and is based on the price per share of the Registrant&#146;s
Common Stock in the Offering. </FONT></TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(5)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Represents 125,000 shares of Common Stock initially available for future grants under the 2004 Employee Stock Purchase Plan (the &#147;2004 ESPP&#148;). The 2004 ESPP provides that
an additional number of shares will automatically be added annually for a period of ten years to the shares authorized for issuance under the 2004 ESPP at each annual meeting of stockholders beginning in 2005. The number of shares added each year
will be equal to the least of: one percent of the Company&#146;s outstanding Common Stock; 150,000 shares, or; an amount that may be determined each year by the Company&#146;s board of directors. </FONT></TD></TR></TABLE> <P
STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P><HR SIZE="3" NOSHADE COLOR="#000000" ALIGN="left"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">3. </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>PART I </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>INFORMATION REQUIRED IN THE SECTION 10 (a) PROSPECTUS </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>ITEM&nbsp;1.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>PLAN INFORMATION </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Not required to be filed with this Registration Statement. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>ITEM&nbsp;2.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Not required to be filed with this Registration Statement. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>PART II </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>INFORMATION REQUIRED IN THE REGISTRATION STATEMENT </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>ITEM&nbsp;3.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>INCORPORATION OF DOCUMENTS BY REFERENCE </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">ACADIA Pharmaceuticals Inc. (the &#147;Registrant&#148;) hereby incorporates by reference into this Registration Statement the following documents
previously filed by the Registrant with the Securities and Exchange Commission (the &#147;Commission&#148;): </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">(a) The Registrant&#146;s prospectus filed on May <U></U>27, 2004 pursuant to Rule 424(b) under the 1933 Act, relating to the registration statement on
Form S-1 (File No. 333-113137), which contains audited financial statements for the Company&#146;s latest fiscal year for which such statements have been filed. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">(b) The description of the Registrant&#146;s Common Stock contained in the Registrant&#146;s registration statement on Form 8-A filed on May 19, 2004
(File No. 000-50768) under the Securities Exchange Act of 1934, as amended, including any amendment or report filed for the purpose of updating such description. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">All documents, reports and definitive proxy or information statements filed pursuant to Section 13(a), 13(c), 14 or 15(d) of
the Securities Exchange Act of 1934 (the &#147;1934 Act&#148;) after the date of this Registration Statement and prior to the filing of a post-effective amendment which indicates that all securities offered hereby have been sold or which deregisters
all securities then remaining unsold shall be deemed to be incorporated by reference into this Registration Statement and to be a part hereof from the date of filing of such documents. Any statement contained in a document incorporated or deemed to
be incorporated herein by reference shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be
incorporated by reference herein modifies or supersedes that statement. Any such statement so modified or superseded shall not constitute a part of this Registration Statement, except as so modified or superseded. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>ITEM&nbsp;4.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>DESCRIPTION OF SECURITIES </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Not Applicable. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>ITEM&nbsp;5.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>INTERESTS OF NAMED EXPERTS AND COUNSEL. </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The validity of the issuance of the common stock being offered by this prospectus and certain other legal matters are being passed upon for us by our
counsel, Cooley Godward <SMALL>LLP</SMALL>, San Diego, California. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>ITEM&nbsp;6.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>INDEMNIFICATION OF DIRECTORS AND OFFICERS. </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">We are incorporated under the laws of the State of Delaware. Section 102 of the Delaware General Corporation Law allows a corporation to eliminate the
personal liability of directors of a corporation to the corporation or its stockholders for monetary damages for a breach of fiduciary duty as a director, except where the director breached his duty of loyalty, failed to act in good faith, engaged
in intentional misconduct or knowingly </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4. </FONT></P>


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<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">violated a law, authorized the payment of a dividend or approved a stock repurchase in violation of Delaware corporate
law or obtained an improper personal benefit. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Section 145 of
the Delaware General Corporation Law provides that a corporation has the power to indemnify a director, officer, employee or agent of the corporation and certain other persons serving at the request of the corporation in related capacities against
amounts paid and expenses incurred in connection with an action or proceeding to which he was or is a party or is threatened to be made a party by reason of such position, if such person shall have acted in good faith and in a manner he reasonably
believed to be in or not opposed to the best interests of the corporation, and, in any criminal proceeding, if such person had no reasonable cause to believe his conduct was unlawful; provided that, in the case of actions brought by or in the right
of the corporation, no indemnification shall be made with respect to any matter as to which such person shall have been adjudged to be liable to the corporation unless and only to the extent that the adjudicating court determines that such
indemnification is proper under the circumstances. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The
Registrant&#146;s amended and restated certificate of incorporation and bylaws include provisions that indemnify directors and officers of the corporation for actions taken in such capacity, if the actions were taken in good faith and in a manner
reasonably believed to be in the best interests of the corporation and, in a criminal proceeding, the director or officer had no reasonable cause to believe that his conduct was unlawful. A director or officer who is successful in defending a claim
will be indemnified for all expenses incurred in connection with his defense. In connection with the Offering, the Registrant will enter into indemnification agreements with its officers and directors that require the Registrant to indemnify such
persons against any and all expenses (including attorneys&#146; fees), witness fees, damages, judgments, fines, settlements and other amounts incurred in connection with any action, suit or proceeding, whether actual or threatened, to which any such
person may be made a party by reason of the fact that such person is or was or at any time becomes a director, an officer or an employee of the Registrant or any of its affiliated enterprises, provided that such person acted in good faith and in a
manner such person reasonably believed to be in or not opposed to our best interests and, with respect to any criminal proceeding, had no reasonable cause to believe his or her conduct was unlawful. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">At present, there is no pending litigation or proceeding involving any of our
directors or executive officers as to which indemnification is required or permitted, and we are not aware of any threatened litigation or proceeding that may result in a claim for indemnification. We have an insurance policy covering our officers
and directors with respect to certain liabilities, including liabilities arising under the 1933 Act or otherwise. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>ITEM&nbsp;7.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>EXEMPTION FROM REGISTRATION CLAIMED </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Not applicable. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>ITEM&nbsp;8.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>EXHIBITS. </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="3%"></TD>
<TD VALIGN="bottom" WIDTH="6%"></TD>
<TD WIDTH="91%"></TD></TR>
<TR>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Exhibit</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="1"><B>Number</B></FONT></P><HR WIDTH="44" SIZE="1" NOSHADE COLOR="#000000"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="1"><B>Description</B></FONT></P><HR WIDTH="65" SIZE="1" NOSHADE ALIGN="left" COLOR="#000000"></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;4.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Registrant&#146;s Amended and Restated Certificate of Incorporation, as currently in effect (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;4.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Form of Registrant&#146;s Amended and Restated Certificate of Incorporation, to be effective upon the closing of the Registrant&#146;s initial public offering (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;4.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Registrant&#146;s Amended and Restated Bylaws, as currently in effect (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;4.4</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Form of common stock certificate of Registrant (incorporated by reference to Exhibit 4.1 to Registration Statement No. 333-52492, dated December 21, 2000)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">&nbsp;&nbsp;5.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Opinion of Cooley Godward LLP</FONT></TD></TR>
</TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">5. </FONT></P>


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<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="3%"></TD>
<TD VALIGN="bottom" WIDTH="4%"></TD>
<TD WIDTH="93%"></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">23.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Consent of Independent Registered Public Accounting Firm </FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">23.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Consent of Counsel (included in Exhibit 5.1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">1997 Stock Option Plan, as amended (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">2004 Equity Incentive Plan (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">2004 Employee Stock Purchase Plan (1)</FONT></TD></TR>
</TABLE><HR WIDTH="8%" SIZE="1" NOSHADE COLOR="#000000" ALIGN="left">
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Filed as an exhibit to the Registrant&#146;s Registration Statement of Form S-1, as amended (File No. 333-113137), filed with the Commission on February 27, 2004, and incorporated
herein by reference. </FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>ITEM&nbsp;9.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>UNDERTAKINGS. </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">A. The undersigned Registrant hereby undertakes: (1) to file, during any period in which offers or sales are being made, a post-effective amendment to
this Registration Statement (i) to include any prospectus required by Section 10(a)(3) of the 1933 Act, (ii) to reflect in the prospectus any facts or events arising after the effective date of this Registration Statement (or the most recent
post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in this Registration Statement and (iii) to include any material information with respect to the plan of
distribution not previously disclosed in this Registration Statement or any material change to such information in this Registration Statement; provided, however, that clauses (1)(i) and (1)(ii) shall not apply if the information required to be
included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the 1934 Act that are incorporated by reference in
this Registration Statement; (2) that for the purpose of determining any liability under the 1933 Act each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein and the offering
of such securities at that time shall be deemed to be the initial bona fide offering thereof and (3) to remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of
the offering. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">B. The undersigned Registrant hereby undertakes
that, for purposes of determining any liability under the 1933 Act, each filing of the Registrant&#146;s annual report pursuant to Section 13(a) or Section 15(d) of the 1934 Act that is incorporated by reference in this Registration Statement shall
be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">C. Insofar as indemnification for liabilities arising under the 1933 Act may
be permitted to directors, officers or controlling persons of the Registrant pursuant to the indemnification provisions summarized in Item 6 or otherwise, the Registrant has been advised that, in the opinion of the Commission, such indemnification
is against public policy as expressed in the 1933 Act, and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director,
officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless
in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the 1933 Act and will be
governed by the final adjudication of such issue. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">6. </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>SIGNATURES </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of San Diego, State of California on May <U></U>27, 2004. </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P><DIV ALIGN="right">
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<TD VALIGN="top" COLSPAN="3"><FONT FACE="Times New Roman" SIZE="2"><B>ACADIA P<SMALL>HARMACEUTICALS</SMALL> I<SMALL>NC</SMALL>.</B></FONT></TD></TR>
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<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">By:</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;U<SMALL>LI</SMALL> H<SMALL>ACKSELL&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SMALL></FONT></P></TD></TR>
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<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
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<TD VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Uli Hacksell, Ph.D.</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Chief Executive Officer</FONT></P></TD></TR>
</TABLE></DIV> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>POWER OF
ATTORNEY </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>K<SMALL>NOW</SMALL> A<SMALL>LL</SMALL>
P<SMALL>ERSONS</SMALL> B<SMALL>Y</SMALL> T<SMALL>HESE</SMALL> P<SMALL>RESENTS</SMALL></B><SMALL></SMALL>, that each person whose signature appears below constitutes and appoints U<SMALL>LI</SMALL> H<SMALL>ACKSELL</SMALL>, P<SMALL>H</SMALL>.D. and
T<SMALL>HOMAS</SMALL> H. A<SMALL>ASEN</SMALL>, and each or either of them, his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all
capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange
Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes
as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their or his or her substitutes or substitute, may lawfully do or cause to be done by virtue hereof. </FONT></P>
<P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the capacities and on the dates indicated. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
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<TD WIDTH="36%"></TD>
<TD VALIGN="bottom" WIDTH="3%"></TD>
<TD WIDTH="17%"></TD></TR>
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<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Signature</B></FONT></P><HR WIDTH="54" SIZE="1" NOSHADE COLOR="#000000"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Title</B></FONT></P><HR WIDTH="25" SIZE="1" NOSHADE COLOR="#000000"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Date</B></FONT></P><HR WIDTH="26" SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
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<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
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<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;U<SMALL>LI</SMALL>
H<SMALL>ACKSELL&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SMALL></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman"
SIZE="2">U<SMALL>LI</SMALL> H<SMALL>ACKSELL</SMALL></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Chief Executive Officer and Director</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2"><I>(Principal Executive Officer)</I></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">May 27, 2004</FONT></TD></TR>
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<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
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<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;T<SMALL>HOMAS</SMALL> H.
A<SMALL>ASEN&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SMALL></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman"
SIZE="2">T<SMALL>HOMAS</SMALL> H. A<SMALL>ASEN</SMALL></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Vice President, Chief Financial Officer, Treasurer and Secretary</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2"><I>(Principal Executive Officer and Accounting Officer)</I></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">May 27, 2004</FONT></TD></TR>
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<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;M<SMALL>ARK</SMALL> R.
B<SMALL>RANN&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SMALL></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman"
SIZE="2">M<SMALL>ARK</SMALL> R. B<SMALL>RANN</SMALL></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">President, Chief Scientific Officer and Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">May 27, 2004</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;L<SMALL>ESLIE</SMALL> L.
I<SMALL>VERSEN&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SMALL></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman"
SIZE="2">L<SMALL>ESLIE</SMALL> L. I<SMALL>VERSEN</SMALL></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Chairman of the Board</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">May 27, 2004</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;G<SMALL>ORDON</SMALL>
B<SMALL>INDER&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SMALL></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman"
SIZE="2">G<SMALL>ORDON</SMALL> B<SMALL>INDER</SMALL></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">May 27, 2004</FONT></TD></TR>
</TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">7. </FONT></P>


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<TD WIDTH="41%"></TD>
<TD VALIGN="bottom" WIDTH="3%"></TD>
<TD WIDTH="36%"></TD>
<TD VALIGN="bottom" WIDTH="3%"></TD>
<TD WIDTH="17%"></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
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<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;C<SMALL>ARL</SMALL> L. G<SMALL>ORDON</SMALL></FONT></P><HR SIZE="1" NOSHADE
COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">C<SMALL>ARL</SMALL> L. G<SMALL>ORDON</SMALL></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">May <U></U>27, 2004</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;L<SMALL>ESTER</SMALL> J. K<SMALL>APLAN</SMALL></FONT></P><HR SIZE="1" NOSHADE
COLOR="#000000"> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">L<SMALL>ESTER</SMALL> J. K<SMALL>APLAN</SMALL></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">May <U></U>27, 2004</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;T<SMALL>ORSTEN</SMALL> R<SMALL>ASMUSSEN</SMALL></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P
STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">T<SMALL>ORSTEN</SMALL> R<SMALL>ASMUSSEN</SMALL></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">May <U></U>27, 2004</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;M<SMALL>ARTIEN</SMALL> <SMALL>VAN</SMALL> O<SMALL>SCH</SMALL></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P
STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">M<SMALL>ARTIEN</SMALL> <SMALL>VAN</SMALL> O<SMALL>SCH</SMALL></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">May <U></U>27, 2004</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;A<SMALL>LAN</SMALL> G. W<SMALL>ALTON</SMALL></FONT></P><HR SIZE="1" NOSHADE COLOR="#000000"> <P
STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">A<SMALL>LAN</SMALL> G. W<SMALL>ALTON</SMALL></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">May <U></U>27, 2004</FONT></TD></TR>
</TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">8. </FONT></P>


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 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>EXHIBIT INDEX </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
SIZE="1">&nbsp;</FONT></P>
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<TD WIDTH="4%"></TD>
<TD VALIGN="bottom" WIDTH="5%"></TD>
<TD WIDTH="91%"></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Exhibit</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="1"><B>Number</B></FONT></P><HR WIDTH="44" SIZE="1" NOSHADE COLOR="#000000"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="1"><B>Description</B></FONT></P><HR WIDTH="65" SIZE="1" NOSHADE ALIGN="left" COLOR="#000000"></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">3.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Registrant&#146;s Amended and Restated Certificate of Incorporation, as currently in effect (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">3.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Form of Registrant&#146;s Amended and Restated Certificate of Incorporation, to be effective upon the closing of the Registrant&#146;s initial public offering (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">3.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Registrant&#146;s Amended and Restated Bylaws, as currently in effect (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Form of common stock certificate of Registrant (incorporated by reference to Exhibit 4.1 to Registration Statement No. 333-52492, dated December 21, 2002)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">5.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Opinion of Cooley Godward LLP</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">23.1&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Consent of Independent Registered Public Accounting Firm </FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">23.2&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Consent of Counsel (included in Exhibit 5.1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.1&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">1997 Stock Option Plan, as amended (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.2&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">2004 Equity Incentive Plan (1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.3&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">2004 Employee Stock Purchase Plan (1)</FONT></TD></TR>
</TABLE><HR WIDTH="8%" SIZE="1" NOSHADE COLOR="#000000" ALIGN="left">
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Filed as an exhibit to the Registrant&#146;s Registration Statement of Form S-1, as amended (File No. 333-113137), filed with the Commission on February 27, 2004, and incorporated
herein by reference. </FONT></TD></TR></TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">9. </FONT></P>

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</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-5.1
<SEQUENCE>2
<FILENAME>dex51.htm
<DESCRIPTION>OPINION OF COOLEY GODWARD LLP
<TEXT>
<HTML><HEAD>
<TITLE>Opinion of Cooley Godward LLP</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>Exhibit 5.1 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>

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<TR>
<TD WIDTH="33%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="31%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="32%"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em">

<IMG SRC="g75860image001.gif" ALT="LOGO"></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT SIZE="1">&nbsp;</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">ATTORNEYS AT LAW</FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">4401 Eastgate Mall</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">San Diego, CA</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">92121-1909</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Main &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;858
550-6000</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Fax&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;858 550-6420</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Broomfield, CO</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">720 566-4000</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Palo Alto, CA</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">650 843-5000</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Reston, VA</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">703 456-8000</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">San Francisco, CA</FONT></P></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">May 27, 2004</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">www.cooley.com</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">415 693-2000</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="4"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">ACADIA Pharmaceuticals Inc.</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">3911 Sorrento Valley Boulevard</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">San Diego, CA 92121</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">D. BRADLEY PECK</FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">(858) 550-6012</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px; margin-left:1.00em; text-indent:-1.00em"><FONT
FACE="Times New Roman" SIZE="2">bpeck@cooley.com</FONT></P></TD></TR>
</TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:2%; text-indent:-2%"><FONT FACE="Times New Roman"
SIZE="2">Ladies and Gentlemen: </FONT></P> <P STYLE="margin-top:0px;margin-bottom:-6px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">You have requested our opinion with respect to
certain matters in connection with the filing by ACADIA P<SMALL>HARMACEUTICALS</SMALL> I<SMALL>NC</SMALL>., a Delaware corporation (the &#147;Company&#148;), of a Registration Statement on Form S-8 (the &#147;Registration Statement&#148;) with the
Securities and Exchange Commission, covering the offering of an aggregate of up to 2,738,823 shares of the Company&#146;s Common Stock, $.0001 par value (the &#147;Shares&#148;), including 2,413,823 shares issuable pursuant to the Company&#146;s
1997 Stock Option Plan (the &#147;Option Plan&#148;), 200,000 shares issuable pursuant to the Company&#146;s 2004 Equity Incentive Plan (the &#147;Incentive Plan&#148;) and 125,000 shares issuable pursuant to the Company&#146;s 2004 Employee Stock
Purchase Plan (the &#147;ESPP&#148;). </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">In connection with this opinion, we have
examined and relied upon the Registration Statement and related prospectus, the Option Plan, the Incentive Plan and the ESPP, the Company&#146;s Amended and Restated Certificate of Incorporation and Bylaws, and the originals or copies certified to
our satisfaction of such records, documents, certificates, memoranda and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. We have assumed the genuineness and authenticity of all
documents submitted to us as originals, the conformity to originals of all documents submitted to us as copies thereof and the due execution and delivery of all documents where due execution and delivery are a prerequisite to the effectiveness
thereof. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">On the basis of the foregoing, and in reliance thereon, we are of the
opinion that the Shares (i) when issued and sold in accordance with the Option Plan or the Incentive Plan, as applicable, the Registration Statement and related prospectus, will be validly issued, fully paid and nonassessable (except as to shares
issued pursuant to certain deferred payment arrangements, which will be fully paid and nonassessable when such deferred payments are made in full), and (ii) when issued and sold in accordance with the ESPP, the Registration Statement and related
prospectus, will be validly issued, fully paid and nonassessable. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">We consent
to the filing of this opinion as an exhibit to the Registration Statement. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
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<TR>
<TD WIDTH="6%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="92%"></TD></TR>
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<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Very truly yours,</FONT></P></TD></TR>
<TR>
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Cooley Godward <SMALL>LLP</SMALL></FONT></P></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">By:</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;D. B<SMALL>RADLEY</SMALL> P<SMALL>ECK</SMALL></FONT></P></TD></TR>
<TR>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><HR SIZE="1" NOSHADE COLOR="#000000"></TD></TR>
<TR>
<TD VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">D. Bradley Peck</FONT></TD></TR>
</TABLE>
</BODY></HTML>

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-23.1
<SEQUENCE>3
<FILENAME>dex231.htm
<DESCRIPTION>CONSENT OF PRICEWATERHOUSECOOPERS
<TEXT>
<HTML><HEAD>
<TITLE>Consent of PricewaterhouseCoopers</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">

 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>Exhibit 23.1 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><U>CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM</U> </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT
SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">We hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of our report dated February 25, 2004, except
as to Note 12 which is as of May 25, 2004, relating to the financial statements of ACADIA Pharmaceuticals Inc., which appears in the Company&#146;s Registration Statement on Form S-1, as amended (File No. 333-113137). </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:2%; text-indent:-2%"><FONT FACE="Times New Roman" SIZE="2">/s/&nbsp;&nbsp;&nbsp;&nbsp;PricewaterhouseCoopers LLP
</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">PricewaterhouseCoopers LLP </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px; margin-left:2%; text-indent:-2%"><FONT FACE="Times New Roman" SIZE="2">San Diego, California </FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px; margin-left:2%; text-indent:-2%"><FONT FACE="Times New Roman" SIZE="2">May 27, 2004 </FONT></P>
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</TEXT>
</DOCUMENT>
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<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>g75860image001.gif
<DESCRIPTION>GRAPHIC
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