Cannabis Use Linked to Severe Self-Disturbance and Dissociation in First-Episode Psychosis
A systematic review of 22 studies found daily high-potency cannabis use was associated with 3-fold higher dissociation odds in first-episode psychosis patients, though symptoms were largely reversible with cessation.
Quick Facts
What This Study Found
Among 3,847 participants across 22 studies, daily high-potency cannabis use was associated with 3.21-fold increased odds of clinically significant dissociation (95% CI 2.14-4.82) and more severe anomalous self-experiences. Cannabis users showed DES-II score elevations of 11-13 points exceeding clinical thresholds. Cannabis-related dissociation showed distinct features including self-world boundary confusion. Approximately 75% showed dissociation reduction following cannabis cessation.
Key Numbers
22 studies, 3,847 participants. Daily high-potency use: OR 3.21 for dissociation. DES-II elevations: 11-13 points. ~75% showed improvement after cessation. Worse functional outcomes: GAF 52 vs 67 in non-users (p<0.001).
How They Did This
Systematic review following PRISMA guidelines, searching four databases (PubMed, Scopus, PsycINFO, Web of Science) from January 1990 to September 2025. 22 studies meeting inclusion criteria with total N=3,847. GRADE certainty assessed as moderate for dissociative symptoms.
Why This Research Matters
This review reveals that cannabis does not just trigger psychotic symptoms but fundamentally disturbs the sense of self in first-episode psychosis patients. The dissociative effects, including feeling disconnected from reality and confusion about self-boundaries, may explain why cannabis-using psychosis patients have worse outcomes. The reversibility finding offers hope.
The Bigger Picture
Understanding that cannabis disrupts fundamental self-experience, not just causing hallucinations or delusions, changes how clinicians should approach cannabis-using psychosis patients. The finding that most patients improve with cessation provides a concrete, evidence-based reason to prioritize cannabis cessation in treatment.
What This Study Doesn't Tell Us
Most studies were observational. Cannot fully establish causation. GRADE certainty was low for self-disturbance outcomes due to limited direct evidence. Heterogeneous assessment tools across studies. Cannot determine pre-existing dissociative tendencies.
Questions This Raises
- ?Does cannabis-induced dissociation represent a distinct psychosis subtype requiring different treatment?
- ?Would the 25% who do not improve with cessation benefit from targeted dissociation-focused therapy?
- ?Are there genetic factors predicting cannabis-related dissociation?
Trust & Context
- Key Stat:
- 3.21x dissociation odds with daily high-potency use
- Evidence Grade:
- Moderate: systematic review with GRADE assessment, moderate certainty for dissociative outcomes, limited self-disturbance data.
- Study Age:
- 2025 study
- Original Title:
- Self-disturbance in first-episode psychosis: Theoretical framework and potential cannabis interactions - a systematic review.
- Published In:
- Frontiers in psychiatry, 16, 1733254 (2025)
- Authors:
- Ricci, Valerio(14), De Berardis, Domenico(9), Martinotti, Giovanni(18), Maina, Giuseppe
- Database ID:
- RTHC-07478
Evidence Hierarchy
Analyzes all available research on a topic using a structured method.
What do these levels mean? →Frequently Asked Questions
Does cannabis cause a different kind of psychosis?
This review found cannabis-related psychosis features distinct dissociative symptoms including confusion about self-boundaries and depersonalization, suggesting it may represent a specific psychosis subtype rather than generic psychosis.
Do the effects reverse if you stop using cannabis?
About 75% of patients showed reduced dissociation after stopping cannabis, suggesting the self-disturbance effects are largely reversible. However, those who continue using had worse long-term outcomes.
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Cite This Study
https://rethinkthc.com/research/RTHC-07478APA
Ricci, Valerio; De Berardis, Domenico; Martinotti, Giovanni; Maina, Giuseppe. (2025). Self-disturbance in first-episode psychosis: Theoretical framework and potential cannabis interactions - a systematic review.. Frontiers in psychiatry, 16, 1733254. https://doi.org/10.3389/fpsyt.2025.1733254
MLA
Ricci, Valerio, et al. "Self-disturbance in first-episode psychosis: Theoretical framework and potential cannabis interactions - a systematic review.." Frontiers in psychiatry, 2025. https://doi.org/10.3389/fpsyt.2025.1733254
RethinkTHC
RethinkTHC Research Database. "Self-disturbance in first-episode psychosis: Theoretical fra..." RTHC-07478. Retrieved from https://rethinkthc.com/research/ricci-2025-selfdisturbance-in-firstepisode-psychosis
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.