v3.26.1
Document and Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2025
Mar. 26, 2026
Jun. 30, 2025
Document and Entity Information      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2025    
Document Transition Report false    
Securities Act File Number 001-38410    
Entity Registrant Name BioXcel Therapeutics, Inc.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 82-1386754    
Entity Address, Address Line One 555 Long Wharf Drive    
Entity Address, City or Town New Haven    
Entity Address, State or Province CT    
Entity Address, Postal Zip Code 06511    
City Area Code 475    
Local Phone Number 238-6837    
Title of 12(b) Security Common Stock    
Trading Symbol BTAI    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 11,021,589
Entity Common Stock, Shares Outstanding   27,074,586  
Auditor Name Ernst & Young LLP    
Auditor Firm ID 42    
Auditor Location Stamford, Connecticut    
Entity Central Index Key 0001720893    
Document Fiscal Period Focus FY    
Amendment Flag false