Cannabis users who developed psychosis showed widespread grey matter loss compared to cannabis users without psychosis
In a pilot MRI study, cannabis users with cannabis-induced psychosis had extensive grey matter reductions in multiple brain regions compared to non-psychotic cannabis users, suggesting psychosis involves additional brain damage beyond cannabis use alone.
Quick Facts
What This Study Found
CIP patients showed extensive grey matter decreases in right superior frontal gyrus, precentral, superior temporal gyrus, bilateral insula, right precuneus, right medial occipital gyrus, right fusiform gyrus, and left hippocampus compared to non-psychotic chronic cannabis users. Grey matter volumes negatively correlated with BPRS-Activity scores in CIP patients.
Key Numbers
10 CIP patients vs. 12 non-psychotic cannabis users. Grey matter reductions found in 8+ brain regions. Negative correlation between BPRS-Activity and GM volumes in CIP group.
How They Did This
Pilot study comparing 3T MRI brain scans of 10 cannabis-induced psychosis patients with 12 non-psychotic chronic cannabis users. Sociodemographic, clinical, and psychosocial variables correlated with brain measures.
Why This Research Matters
Understanding what distinguishes cannabis users who develop psychosis from those who do not could identify biomarkers for psychosis risk before symptoms emerge.
The Bigger Picture
The selective brain reductions in psychosis patients suggest that cannabis-induced psychosis is not simply heavy cannabis use but involves additional neurobiological vulnerability or damage.
What This Study Doesn't Tell Us
Very small pilot study; cross-sectional design cannot determine if brain changes preceded or followed psychosis onset; no healthy non-using control group; medication effects possible in CIP group.
Questions This Raises
- ?Do these brain reductions exist before psychosis onset and could serve as early warning signs?
- ?Would a larger study with healthy controls clarify which changes are cannabis-related vs. psychosis-specific?
Trust & Context
- Key Stat:
- 8+ brain regions showed grey matter reductions in psychosis patients vs. non-psychotic users
- Evidence Grade:
- Very small pilot study (n=22) without healthy controls; designed to generate hypotheses for larger studies.
- Study Age:
- Published in 2020.
- Original Title:
- Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study.
- Published In:
- Journal of visualized experiments : JoVE (2020)
- Authors:
- Delvecchio, Giuseppe(2), Oldani, Lucio, Mandolini, Gian Mario, Pigoni, Alessandro, Ciappolino, Valentina, Schiena, Giandomenico, Lazzaretti, Matteo, Caletti, Elisabetta, Barbieri, Viviana, Cinnante, Claudia, Triulzi, Fabio, Brambilla, Paolo
- Database ID:
- RTHC-02508
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Do all heavy cannabis users develop these brain changes?
No. The brain reductions were found only in cannabis users who developed psychosis, not in those who used cannabis heavily without developing psychosis. This suggests additional vulnerability factors beyond cannabis use itself.
Could these brain changes be used to predict psychosis?
That is a possibility the authors suggest, but this pilot study was too small to establish predictive value. Larger prospective studies would be needed to determine if these patterns could identify at-risk individuals before psychosis develops.
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Cite This Study
https://rethinkthc.com/research/RTHC-02508APA
Delvecchio, Giuseppe; Oldani, Lucio; Mandolini, Gian Mario; Pigoni, Alessandro; Ciappolino, Valentina; Schiena, Giandomenico; Lazzaretti, Matteo; Caletti, Elisabetta; Barbieri, Viviana; Cinnante, Claudia; Triulzi, Fabio; Brambilla, Paolo. (2020). Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study.. Journal of visualized experiments : JoVE. https://doi.org/10.3791/60881
MLA
Delvecchio, Giuseppe, et al. "Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study.." Journal of visualized experiments : JoVE, 2020. https://doi.org/10.3791/60881
RethinkTHC
RethinkTHC Research Database. "Brain Morphology of Cannabis Users With or Without Psychosis..." RTHC-02508. Retrieved from https://rethinkthc.com/research/delvecchio-2020-brain-morphology-of-cannabis
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.