How THC and CBD affect the brain's reward system, and what that means for psychosis
THC appears to disrupt reward-related brain regions in ways that correlate with psychotic symptoms, while CBD may push those same regions in the opposite direction.
Quick Facts
What This Study Found
THC modulated activity in the striatum, midbrain, insula, and anterior cingulate during reward processing, with some effects correlating with the severity of THC-induced psychotic symptoms. CBD appeared to modulate the same reward and salience regions in the opposite direction.
Key Numbers
People with psychosis show increased striatal presynaptic dopamine synthesis and release. Cannabis users generally show impaired presynaptic dopaminergic function, though acute THC challenges produced only modest effects on striatal dopamine.
How They Did This
Narrative review combining preclinical and human neuroimaging evidence. A systematic search identified acute cannabinoid drug-challenge studies using neuroimaging in healthy subjects and people with psychosis.
Why This Research Matters
Both psychosis and THC use involve altered dopamine signaling in the striatum. Understanding whether cannabinoid effects on reward processing underlie psychotic symptoms could clarify why some cannabis users develop psychosis while others do not.
The Bigger Picture
The overlap between cannabinoid effects on reward circuitry and the neurobiology of psychosis raises the question of whether endocannabinoid dysfunction and reward processing abnormalities are mechanistically linked in psychotic disorders.
What This Study Doesn't Tell Us
Narrative review rather than systematic meta-analysis. Acute THC challenge studies may not reflect chronic cannabis use. The relationship between reward processing changes and psychotomimetic effects remains correlational.
Questions This Raises
- ?Does CBD's opposing effect on reward regions explain its potential antipsychotic properties?
- ?Could individual differences in reward circuitry predict psychosis risk from cannabis use?
Trust & Context
- Key Stat:
- THC and CBD modulated the same reward and salience brain regions in opposite directions
- Evidence Grade:
- Narrative review synthesizing preclinical and human imaging data with some systematic search elements.
- Study Age:
- Published in 2022, reviewing literature up to that point.
- Original Title:
- Cannabinoids, reward processing, and psychosis.
- Published In:
- Psychopharmacology, 239(5), 1157-1177 (2022)
- Authors:
- Gunasekera, Brandon(4), Diederen, Kelly, Bhattacharyya, Sagnik(39)
- Database ID:
- RTHC-03891
Evidence Hierarchy
Summarizes existing research without a strict systematic method.
What do these levels mean? →Frequently Asked Questions
Does THC cause psychosis through the reward system?
The review found overlap between THC's effects on reward circuitry and the neurobiology of psychosis, but whether reward processing changes actually cause psychotic symptoms remains unclear.
Can CBD counteract THC's effects on the brain?
Imaging evidence suggests CBD modulates reward and salience regions in the opposite direction to THC, though the clinical significance of this opposition needs further study.
Read More on RethinkTHC
- THC-amygdala-anxiety-brain
- anandamide-weed-withdrawal
- cannabinoid-receptors-recovery-time
- cannabis-developing-brain-teenagers
- cant-enjoy-anything-without-weed
- dopamine-recovery-after-quitting-weed
- endocannabinoid-system-explained-simply
- endocannabinoid-system-withdrawal
- nervous-system-weed-withdrawal-fight-flight
- teen-weed-use-under-18-effects-brain
- thc-brain-withdrawal
- thc-prefrontal-cortex-brain-effects
- weed-cortisol-stress-hormones
- weed-memory-loss-recovery
- weed-motivation-amotivational-syndrome
- weed-nervous-system-effects
- weed-reward-system-brain
Cite This Study
https://rethinkthc.com/research/RTHC-03891APA
Gunasekera, Brandon; Diederen, Kelly; Bhattacharyya, Sagnik. (2022). Cannabinoids, reward processing, and psychosis.. Psychopharmacology, 239(5), 1157-1177. https://doi.org/10.1007/s00213-021-05801-2
MLA
Gunasekera, Brandon, et al. "Cannabinoids, reward processing, and psychosis.." Psychopharmacology, 2022. https://doi.org/10.1007/s00213-021-05801-2
RethinkTHC
RethinkTHC Research Database. "Cannabinoids, reward processing, and psychosis." RTHC-03891. Retrieved from https://rethinkthc.com/research/gunasekera-2022-cannabinoids-reward-processing-and
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.