Acute and chronic cannabis vapor exposure produces immediate and delayed impacts on phases of fear learning in a sex specific manner.
Psychopharmacology February 1, 2026 Savannah H M Lightfoot, Andrei S Nastase, Gabriela Costa Lenz Cesar et al.
In a rodent model of fear conditioning, acute exposure to THC-dominant cannabis vapor before fear learning did not affect initial fear acquisition but impaired fear recall in females 24 hours later and prevented spontaneous recovery of conditioned fear in both sexes after two weeks. Acute cannabis before extinction training impaired extinction in females while enhancing it in males. Chronic THC exposure before conditioning initially potentiated fear responses, mainly in females, but did not affect spontaneous recovery. Cannabis exposure has complex effects on fear memory, though acute exposure before fear learning may destabilize fear memory long term, with potential implications for PTSD.