Abstract
BACKGROUND: Cannabis use may be linked with anhedonia and apathy. However, previous studies have shown mixed results, and few have examined the association between cannabis use and specific reward sub-processes. Adolescents may be more vulnerable than adults to harmful effects of cannabis. This study investigated (1) the association between non-acute cannabis use and apathy, anhedonia, pleasure, and effort-based decision-making for reward; and (2) whether these relationships were moderated by age group.
METHODS: We used data from the "CannTeen" study. Participants were 274 adult (26-29 years) and adolescent (16-17 years) cannabis users (1-7 d/wk use in the past 3 months) and gender- and age-matched controls. Anhedonia was measured with the Snaith-Hamilton Pleasure Scale (n = 274), and apathy was measured with the Apathy Evaluation Scale (n = 215). Effort-based decision-making for reward was measured with the Physical Effort task (n = 139), and subjective wanting and liking of rewards was measured with the novel Real Reward Pleasure task (n = 137).
RESULTS: Controls had higher levels of anhedonia than cannabis users (F1,258 = 5.35, P = .02, η p2 = .02). There were no other significant effects of user-group and no significant user-group*age-group interactions. Null findings were supported by post hoc Bayesian analyses.
CONCLUSION: Our results suggest that cannabis use at a frequency of 3 to 4 d/wk is not associated with apathy, effort-based decision-making for reward, reward wanting, or reward liking in adults or adolescents. Cannabis users had lower anhedonia than controls, albeit at a small effect size. These findings are not consistent with the hypothesis that non-acute cannabis use is associated with amotivation.
Original language | English |
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Pages (from-to) | 9-19 |
Number of pages | 11 |
Journal | International Journal of Neuropsychopharmacology |
Volume | 26 |
Issue number | 1 |
Early online date | 24 Aug 2022 |
DOIs | |
Publication status | Published - 19 Jan 2023 |
Bibliographical note
This work was supported by a grant from the Medical Research Council (MRC), MR/P012728/1, to H.V.C. and T.P.F. M.S. is funded by an Aker Scholarship from the Aker Foundation. V.V. was funded by a fellowship from the National Institute for Health Research (NIHR) UCLH Biomedical Research Centre. A.B. was funded by a fellowship from the NIHR UCLH Biomedical Research Centre. B.J.S. receives funding from the Wallitt Foundation, Eton College, and a Wellcome Trust Collaborative Award (200181/Z//15/Z). C.L. is funded by a Wellcome Trust Collaborative Award (200181/Z//15/Z), and their research is conducted within the NIHR Cambridge Biomedical Research Centre (Mental Health Theme and Neurodegeneration Theme) and the NIHR Brain Injury MedTech and in vitro diagnostics Co-operative (MIC), Cambridge. H.V.C. is supported by grants from the UK MRC (MR/P012728/1) UK Department of Health and by the NIHR UCLH Biomedical Research Centre.Keywords
- Humans
- Adult
- Adolescent
- Anhedonia
- Cannabis
- Decision Making
- Apathy
- Pleasure
- Bayes Theorem
- Motivation
- Cannabinoid Receptor Agonists/pharmacology
- Hallucinogens/pharmacology
- Reward