Statement of Changes in Beneficial Ownership (4)

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^* BAKER BROS. ADVISORS LP	2. Issuer Name and Ticker or Trading Symbol ACADIA PHARMACEUTICALS INC [ ACAD ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __ X __ Director __ X __ 10% Owner _____ Officer (give title below) _____ Other (specify below)
(Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR	3. Date of Earliest Transaction (MM/DD/YYYY) 10/13/2017
(Street) NEW YORK, NY 10014 (City) (State) (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _ X _ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock								452540	I	See Footnotes ⁽¹⁾ ⁽⁵⁾ ⁽⁶⁾
Common Stock								3029953	I	See Footnotes ⁽²⁾ ⁽⁵⁾ ⁽⁶⁾
Common Stock	10/13/2017		M		1426590 ⁽³⁾	A	$1.38	23763865	I	See Footnotes ⁽⁴⁾ ⁽⁵⁾ ⁽⁶⁾
Common Stock	10/13/2017		F		55457 ⁽³⁾	D	$35.40	23708408	I	See Footnotes ⁽⁴⁾ ⁽⁵⁾ ⁽⁶⁾

*Table II - Derivative Securities Beneficially Owned ( e.g.* , puts, calls, warrants, options, convertible securities)**
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)			11. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock Warrant (right to buy)	$1.38	10/13/2017		M			1426590	7/12/2011	1/11/2018	Common Stock	1426590	⁽⁷⁾	0	I	See Footnotes ⁽⁴⁾ ⁽⁵⁾ ⁽⁶⁾

Explanation of Responses:
(1)	As a result of their ownership interest in 14159 Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in 452,540 shares of Common Stock of ACADIA Pharmaceuticals Inc. (the "Issuer") beneficially owned by 14159, L.P. ("14159"), a limited partnership of which the sole general partner is 14159 Capital, L.P., a limited partnership of which the sole general partner is 14159 Capital (GP), LLC, due to 14159 Capital, L.P.'s right to receive an allocation of a portion of the profits from 14159.
(2)	As a result of their ownership interest in Baker Biotech Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in 3,029,953 shares of Common Stock of the Issuer beneficially owned by 667, L.P. ("667"), a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.
(3)	On October 13, 2017, Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 14159 and 667, the "Funds") exercised a warrant to purchase 1,426,590 shares of the common stock of the Issuer for $1.38 per share ("2018 Warrants"). Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding of 55,457 of the 2018 Warrant shares to pay the exercise price and issuing to Life Sciences the remaining 1,371,133 shares of common stock of the Issuer. The Issuer also paid $29.30 to Life Sciences in fractional shares. The Issuer's Board of Directors approved the exercise of the 2018 Warrants by Life Sciences on the cashless basis described in this footnote in advance of such exercise.
(4)	As a result of their ownership interest in Baker Brothers Life Sciences Capital (GP), LLC, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in the Issuer's shares of common stock reported in column 5 of Table I directly held by Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.
(5)	Baker Bros. Advisors LP (the "Adviser") 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. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are principals of the Adviser GP. 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 have relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held by the Funds.
(6)	Julian C. Baker, Felix J. Baker, the Adviser GP 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, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.
(7)	Pursuant to Instruction 4(c)(iii), this response has been left blank.

Remarks:
Julian C. Baker, a principal and Dr. Stephen R. Biggar, an employee of Baker Bros. Advisors LP are directors of ACADIA Pharmaceuticals Inc. (the "Issuer"). 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 the Issuer.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
BAKER BROS. ADVISORS LP 860 WASHINGTON STREET 3RD FLOOR NEW YORK, NY 10014	X	X
14159, L.P. 860 WASHINGTON STREET, 3RD FLOOR NEW YORK, NY 10014	X	X
667, L.P. 860 WASHINGTON STREET, 3RD FLOOR NEW YORK, NY 10014	X	X
Baker Bros. Advisors (GP) LLC 860 WASHINGTON STREET 3RD FLOOR NEW YORK, NY 10014	X	X
Baker Brothers Life Sciences LP 860 WASHINGTON STREET 3RD FLOOR NEW YORK, NY 10014	X	X
BAKER FELIX 860 WASHINGTON STREET 3RD FLOOR NEW YORK, NY 10014	X	X
BAKER JULIAN 860 WASHINGTON STREET, 3RD FLOOR NEW YORK, NY 10014	X	X

Signatures
By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing		10/16/2017
^** Signature of Reporting Person		Date
Baker Bros. Advisors LP, 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		10/16/2017
^** Signature of Reporting Person		Date
Baker Bros. Advisors LP, 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		10/16/2017
^** Signature of Reporting Person		Date
By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing		10/16/2017
^** Signature of Reporting Person		Date
Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to BAKER BROTHERS LIFE SCIENCES, L.P., pursuant to authority granted by Baker Brothers Life Sciences Capital, L.P., GP to Baker Brothers Life Sciences, L.P., Name: Scott L. Lessing, Title: President /s/		10/16/2017
^** Signature of Reporting Person		Date
/s/ Felix J. Baker		10/16/2017
^** Signature of Reporting Person		Date
/s/ Julian C. Baker		10/16/2017
^** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
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