Chronic cannabis use is associated with impaired fear extinction in humans.
The use of fear conditioning and extinction paradigms to examine intermediate phenotypes of anxiety and stress-related disorders has facilitated the identification of neurobiological mechanisms that underlie specific components of abnormal psychological functioning. Across species, acute pharmacologic manipulation of the endogenous cannabinoid system has provided evidence of its critical role in fear extinction, but the effects of chronic cannabis on extinction are relatively understudied. In rats, chronic cannabinoid administration impairs fear extinction in a drug-free state. Here we examine whether chronic cannabis use is associated with impaired fear extinction in humans. Participants were healthy chronic cannabis users (n = 20) and nonuser controls with minimal lifetime cannabis use (n = 20) matched on age, sex, and race who all screened negative for psychiatric disorders. A 2-day differential fear conditioning paradigm was used to test the hypothesis that chronic cannabis use would be associated with impaired extinction of the skin conductance response. Consistent with hypotheses, chronic cannabis use was associated with reduced within-session extinction of skin conductance response on Day 1 (d = 0.78), and between-session extinction on Day 2 (d = 0.76). Unexpectedly, cannabis use was also associated with reduced subjective differentiation between threat and safety stimuli during conditioning. Replication and translation of findings are necessary to test potential mechanisms directly and examine whether impairments can be reversed pharmacologically or after a period of cannabis abstinence. (PsycINFO Database Record
Institute for Mental Health Research, The University of Texas at Austin.
Santiago
S
Papini
Department of Psychology, City University of New York-City College.
Lesia M
LM
Ruglass
Department of Psychology, City University of New York-City College.
Teresa
T
Lopez-Castro
Institute for Mental Health Research, The University of Texas at Austin.
Mark B
MB
Powers
Institute for Mental Health Research, The University of Texas at Austin.
Jasper A J
JA
Smits
Gordon F. Derner Institute for Advanced Psychological Studies, Adelphi University.
Denise A
DA
Hien
D000328:Adult; D002186:Cannabinoids / Q000009:adverse effects / Q000494:pharmacology*; D002188:Cannabis; D005108:Extinction, Psychological / Q000187:drug effects*; D005239:Fear / Q000187:drug effects*; D005260:Female; D005712:Galvanic Skin Response / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
D002186:Cannabinoids