Smoked cannabis' psychomotor and neurocognitive effects in occasional and frequent smokers.
Δ9-Tetrahydrocannabinol (THC), the primary psychoactive constituent in cannabis, impairs psychomotor performance, cognition and driving ability; thus, driving under the influence of cannabis is a public safety concern. We documented cannabis' psychomotor, neurocognitive, subjective and physiological effects in occasional and frequent smokers to investigate potential differences between these smokers. Fourteen frequent (≥4x/week) and 11 occasional (<2x/week) cannabis smokers entered a secure research unit ∼19 h prior to smoking one 6.8% THC cigarette. Cognitive and psychomotor performance was evaluated with the critical tracking (CTT), divided attention (DAT), n-back (working memory) and Balloon Analog Risk (BART) (risk-taking) tasks at -1.75, 1.5, 3.5, 5.5 and 22.5 h after starting smoking. GLM (General Linear Model) repeated measures ANOVA was utilized to compare scores. Occasional smokers had significantly more difficulty compensating for CTT tracking error compared with frequent smokers 1.5 h after smoking. Divided attention performance declined significantly especially in occasional smokers, with session × group effects for tracking error, hits, false alarms and reaction time. Cannabis smoking did not elicit session × group effects on the n-back or BART. Controlled cannabis smoking impaired psychomotor function, more so in occasional smokers, suggesting some tolerance to psychomotor impairment in frequent users. These data have implications for cannabis-associated impairment in driving under the influence of cannabis cases.
Chemistry and Drug Metabolism Section, Clinical Pharmacology and Therapeutic Research Branch, NIDA IRP, 251 Bayview Boulevard, Suite 200 Room 05A-721, Baltimore, MD 21224, USA Program in Toxicology, University of Maryland Baltimore, Baltimore, MD, USA.
Nathalie A
NA
Desrosiers
Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
Johannes G
JG
Ramaekers
Chemistry and Drug Metabolism Section, Clinical Pharmacology and Therapeutic Research Branch, NIDA IRP, 251 Bayview Boulevard, Suite 200 Room 05A-721, Baltimore, MD 21224, USA Present address: Laboratoire de Psychologie des Pays de la Loire, Faculté de Psychologie, Université de Nantes, Nantes, France.
Emeline
E
Chauchard
Chemistry and Drug Metabolism Section, Clinical Pharmacology and Therapeutic Research Branch, NIDA IRP, 251 Bayview Boulevard, Suite 200 Room 05A-721, Baltimore, MD 21224, USA Present address: Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA.
David A
DA
Gorelick
Chemistry and Drug Metabolism Section, Clinical Pharmacology and Therapeutic Research Branch, NIDA IRP, 251 Bayview Boulevard, Suite 200 Room 05A-721, Baltimore, MD 21224, USA mhuestis@intra.nida.nih.gov.
Marilyn A
MA
Huestis
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D003071:Cognition / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007175:Impulsive Behavior / Q000187:drug effects; D008297:Male; D008385:Marijuana Smoking / Q000097:blood / Q000453:epidemiology / Q000523:psychology*; D008570:Memory, Short-Term / Q000187:drug effects; D008875:Middle Aged; D011597:Psychomotor Performance / Q000187:drug effects*; D012309:Risk-Taking; D065852:Spatial Memory / Q000187:drug effects; D055815:Young Adult