v3.19.2
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Jul. 24, 2019
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Trading Symbol ACAD  
Entity Registrant Name ACADIA PHARMACEUTICALS INC  
Entity Central Index Key 0001070494  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Common Stock, Shares Outstanding   144,487,428
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity File Number 000-50768  
Entity Tax Identification Number 061376651  
Entity Address, Address Line One 3611 Valley Centre Drive, Suite 300  
Entity Address, City or Town San Diego  
Entity Address, State or Province California  
Entity Address, Postal Zip Code 92130  
City Area Code 858  
Local Phone Number 558-2871