Justin Matheson1, Robert E Mann2, Beth Sproule3, Marilyn A Huestis4, Christine M Wickens2, Gina Stoduto5, Tony P George6, Jürgen Rehm7, Bernard Le Foll8, Bruna Brands9. 1. Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, 27 King's College Circle, Toronto, Ontario M5S3H7, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario M5S2S1, Canada. Electronic address: justin.matheson@camh.ca. 2. Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario M5S2S1, Canada; Dalla Lana School of Public Health, University of Toronto, 155 College Street, Toronto, Ontario M5T3M7, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T1R8, Canada. 3. Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S3M2, Canada; Pharmacy Department, Centre for Addiction and Mental Health, 1001 Queen Street, Toronto, Ontario M6J1H4, Canada; Department of Psychiatry, Faculty of Medicine, University of Toronto, 250 College Street, Toronto, Ontario M5T1R8, Canada. 4. Institute of Emerging Health Professions, Thomas Jefferson University, 1020 Walnut Street, Philadelphia, PA 19107, United States. 5. Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario M5S2S1, Canada. 6. Department of Psychiatry, Faculty of Medicine, University of Toronto, 250 College Street, Toronto, Ontario M5T1R8, Canada; Addictions Division, Centre for Addiction and Mental Health, 100 Stokes Street, Toronto, Ontario M6J1H4, Canada; Institute of Medical Sciences, University of Toronto, 1 King's College Circle, Room 2374, Toronto, Ontario M5S 1A8, Canada. 7. Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario M5S2S1, Canada; Dalla Lana School of Public Health, University of Toronto, 155 College Street, Toronto, Ontario M5T3M7, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T1R8, Canada; Department of Psychiatry, Faculty of Medicine, University of Toronto, 250 College Street, Toronto, Ontario M5T1R8, Canada. 8. Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, 27 King's College Circle, Toronto, Ontario M5S3H7, Canada; Department of Psychiatry, Faculty of Medicine, University of Toronto, 250 College Street, Toronto, Ontario M5T1R8, Canada; Addictions Division, Centre for Addiction and Mental Health, 100 Stokes Street, Toronto, Ontario M6J1H4, Canada; Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario M5S2S1, Canada; Department of Family and Community Medicine, University of Toronto, 500 University Avenue, 5th Floor, Toronto, Ontario M5G 1V7, Canada. 9. Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, 27 King's College Circle, Toronto, Ontario M5S3H7, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario M5S2S1, Canada; Controlled Substances and Cannabis Directorate, Health Canada, Ottawa, Ontario, Canada.
Abstract
OBJECTIVES: To examine acute and residual mood and cognitive performance in young adult regular cannabis users following smoked cannabis. METHODS:Ninety-one healthy young adults completed this double-blind, placebo-controlled, parallel-groups study. Participants were randomized to receive active (12.5% THC) or placebo cannabis with a 2:1 allocation ratio, and mood [Profile of Mood States (POMS)] and cognitive performance [Hopkins Verbal Learning Test - Revised (HVLT-R), Digit Symbol Substitution Test (DSST), Continuous Performance Test (CPT), grooved pegboard (GPB)] were assessed before and 1, 24, and 48 (h) after smoking cannabis ad libitum. High and Low THC groups were based on blood THC concentrations. RESULTS: One hour after smoking cannabis, compared to Placebo, in both the High and Low THC groups, there were increases in POMS Arousal and Positive Mood, and in the High THC group only, increases in Confusion, Friendliness, and Elation, and a decrease in Fatigue. Increases in Friendliness and Elation in the High THC group remained significant for 24 h. The only significant acute effect of cannabis on cognition was a decrease in the percent of words retained in the HVLT-R in the High THC group compared to Placebo (mean difference = 15.8%, 95% CI = 3.6-28.0%, p = 0.006). Unexpectedly, compared to Placebo, both the High and Low THC groups improved in DSST performance at 48 h (p ≤ 0.016). CONCLUSIONS: Under the present experimental conditions, in young regular cannabis users, smoking cannabis ad libitum had significant effects on mood, some of which persisted 24 h later, yet minimal effects on cognition, and no evidence of residual cognitive impairment.
RCT Entities:
OBJECTIVES: To examine acute and residual mood and cognitive performance in young adult regular cannabis users following smoked cannabis. METHODS: Ninety-one healthy young adults completed this double-blind, placebo-controlled, parallel-groups study. Participants were randomized to receive active (12.5% THC) or placebo cannabis with a 2:1 allocation ratio, and mood [Profile of Mood States (POMS)] and cognitive performance [Hopkins Verbal Learning Test - Revised (HVLT-R), Digit Symbol Substitution Test (DSST), Continuous Performance Test (CPT), grooved pegboard (GPB)] were assessed before and 1, 24, and 48 (h) after smoking cannabis ad libitum. High and Low THC groups were based on blood THC concentrations. RESULTS: One hour after smoking cannabis, compared to Placebo, in both the High and Low THC groups, there were increases in POMS Arousal and Positive Mood, and in the High THC group only, increases in Confusion, Friendliness, and Elation, and a decrease in Fatigue. Increases in Friendliness and Elation in the High THC group remained significant for 24 h. The only significant acute effect of cannabis on cognition was a decrease in the percent of words retained in the HVLT-R in the High THC group compared to Placebo (mean difference = 15.8%, 95% CI = 3.6-28.0%, p = 0.006). Unexpectedly, compared to Placebo, both the High and Low THC groups improved in DSST performance at 48 h (p ≤ 0.016). CONCLUSIONS: Under the present experimental conditions, in young regular cannabis users, smoking cannabis ad libitum had significant effects on mood, some of which persisted 24 h later, yet minimal effects on cognition, and no evidence of residual cognitive impairment.
Authors: Jason P Connor; Daniel Stjepanović; Bernard Le Foll; Eva Hoch; Alan J Budney; Wayne D Hall Journal: Nat Rev Dis Primers Date: 2021-02-25 Impact factor: 52.329