Abstract
BACKGROUND: Adolescents may respond differently to cannabis than adults, yet no previous functional magnetic resonance imaging study has examined acute cannabis effects in this age group. In this study, we investigated the neural correlates of reward anticipation after acute exposure to cannabis in adolescents and adults.
METHODS: This was a double-blind, placebo-controlled, randomized, crossover experiment. Forty-seven adolescents (n = 24, 12 females, ages 16-17 years) and adults (n = 23, 11 females, ages 26-29 years) matched on cannabis use frequency (0.5-3 days/week) completed the Monetary Incentive Delay task during functional magnetic resonance imaging after inhaling cannabis with 0.107 mg/kg Δ⁹-tetrahydrocannabinol ("THC") (8 mg THC for a 75-kg person) or with THC plus 0.320 mg/kg cannabidiol ("THC+CBD") (24 mg CBD for a 75-kg person), or placebo cannabis. We investigated reward anticipation activity with whole-brain analyses and region of interest analyses in the right and left ventral striatum, right and left anterior cingulate cortex, and right insula.
RESULTS: THC reduced anticipation activity compared with placebo in the right (p = .005, d= 0.49) and left (p = .003, d = 0.50) ventral striatum and the right insula (p = .01, d = 0.42). THC+CBD reduced activity compared with placebo in the right ventral striatum (p = .01, d = 0.41) and right insula (p = .002, d = 0.49). There were no differences between "THC" and "THC+CBD" conditions and no significant drug by age group interaction effect, supported by Bayesian analyses. There were no significant effects in the whole-brain analyses.
CONCLUSIONS: In weekly cannabis users, cannabis suppresses the brain's anticipatory reward response to money, and CBD does not modulate this effect. Furthermore, the adolescent reward circuitry is not differentially sensitive to acute effects of cannabis on reward anticipation.
Original language | English |
---|---|
Pages (from-to) | 219-229 |
Number of pages | 11 |
Journal | Biological Psychiatry: Cognitive Neuroscience and Neuroimaging |
Volume | 8 |
Issue number | 2 |
Early online date | 28 Oct 2022 |
DOIs | |
Publication status | Published - 28 Feb 2023 |
Bibliographical note
Funding Information:This study was funded by the Medical Research Council (Grant No. MR/P012728/1 [to HVC and TPF]); an Aker Scholarship from the Aker Foundation (to MS); a fellowship from the National Institute for Health Research (NIHR) UCLH Biomedical Research Centre (to AB) and a NIHR Academic Clinical Fellowship (to AB); the Lundbeck Foundation and the Leverhulme Trust (to BJS); the UK MRC (Grant No. MR/P012728/1), UK Department of Health, and the NIHR UCLH Biomedical Research Centre [to HVC]; and a Wellcome Trust Collaborative Award (Grant No. 200181/Z//15/Z [to CL]). BJS's and CL's research is conducted within the NIHR Cambridge Biomedical Research Centre (Mental-Health Theme and Neurodegeneration Theme) and the NIHR MedTech in vitro diagnostics Co-operative.
The data from this study are not available
Keywords
- Adolescent
- Adult
- Female
- Humans
- Bayes Theorem
- Cannabidiol/pharmacology
- Cannabis
- Dronabinol/pharmacology
- Hallucinogens
- Reward
- Cross-Over Studies
- CBD
- THC
- fMRI
- Adolescents
ASJC Scopus subject areas
- Clinical Neurology
- Biological Psychiatry
- Cognitive Neuroscience
- Radiology Nuclear Medicine and imaging