Does cannabis use worsen dissociation and functioning in first-episode psychosis over time?
A prospective study of 70 first-episode psychosis patients found that those with cannabis use disorder had higher dissociative symptoms and worse functioning that persisted at 8 months, while non-users' functioning improved over the same period.
Quick Facts
What This Study Found
Cannabis-using FEP patients showed higher positive symptoms, higher dissociative experiences (DES-II), and worse functioning (GAF) than non-users at onset. At 8-month follow-up, cannabis users still had elevated positive symptoms and dissociation. Functioning worsened over time in cannabis users while improving in non-users, despite comparable antipsychotic treatment.
Key Numbers
70 patients (35 CUD, 35 non-CUD); cannabis users had higher positive symptoms, dissociation, and worse functioning at baseline; at 8 months: positive symptoms and dissociation still elevated in cannabis group; functioning worsened in cannabis group vs improved in non-cannabis group
How They Did This
Prospective cohort study of 70 first-episode psychosis patients (35 with CUD, 35 without) recruited from Italian psychiatric inpatient facilities (2014-2019). Assessed at FEP onset, 4 months, and 8 months using PANSS, GAF, and DES-II.
Why This Research Matters
The divergent trajectory of functioning (worsening with cannabis use, improving without) is particularly concerning. It suggests cannabis use during first-episode psychosis actively undermines recovery rather than just being a marker of worse prognosis.
The Bigger Picture
The dissociative component of cannabis-associated psychosis is often overlooked. If cannabis promotes both psychotic and dissociative symptoms while undermining functional recovery, it represents a more complex clinical problem than simply managing hallucinations and delusions.
What This Study Doesn't Tell Us
Small sample (35 per group). Italian inpatient population may not generalize. Cannot determine if cannabis caused the worse trajectory or if patients with worse prognosis are more likely to continue using cannabis.
Questions This Raises
- ?Does cannabis cessation reverse the functional decline?
- ?Is dissociation a mediator between cannabis use and poor psychosis outcomes?
- ?Would specifically targeting dissociation in treatment improve outcomes for cannabis-using psychosis patients?
Trust & Context
- Key Stat:
- Cannabis users: functioning worsened; non-users: improved
- Evidence Grade:
- Prospective design with 8-month follow-up and matched comparison group, but small sample and potential confounding.
- Study Age:
- Published in 2021; the role of dissociation in cannabis-associated psychosis is gaining research attention.
- Original Title:
- Cannabis use disorder and dissociation: A report from a prospective first-episode psychosis study.
- Published In:
- Drug and alcohol dependence, 229(Pt A), 109118 (2021)
- Authors:
- Ricci, V, Ceci, F, Di Carlo, F, Lalli, A, Ciavoni, L, Mosca, A, Sepede, G, Salone, A, Quattrone, D, Fraticelli, S, Maina, G, Martinotti, G
- Database ID:
- RTHC-03455
Evidence Hierarchy
Enrolls participants and follows them forward in time.
What do these levels mean? →Frequently Asked Questions
What is dissociation in psychosis?
Dissociation involves feeling disconnected from reality, one's body, or one's thoughts. This study found cannabis-using psychosis patients experienced more dissociative symptoms than non-users, which persisted over 8 months.
Does cannabis prevent recovery from psychosis?
In this study, patients with cannabis use disorder saw their functioning worsen over 8 months while non-users improved, despite receiving similar antipsychotic treatment. This suggests cannabis may actively interfere with recovery.
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Cite This Study
https://rethinkthc.com/research/RTHC-03455APA
Ricci, V; Ceci, F; Di Carlo, F; Lalli, A; Ciavoni, L; Mosca, A; Sepede, G; Salone, A; Quattrone, D; Fraticelli, S; Maina, G; Martinotti, G. (2021). Cannabis use disorder and dissociation: A report from a prospective first-episode psychosis study.. Drug and alcohol dependence, 229(Pt A), 109118. https://doi.org/10.1016/j.drugalcdep.2021.109118
MLA
Ricci, V, et al. "Cannabis use disorder and dissociation: A report from a prospective first-episode psychosis study.." Drug and alcohol dependence, 2021. https://doi.org/10.1016/j.drugalcdep.2021.109118
RethinkTHC
RethinkTHC Research Database. "Cannabis use disorder and dissociation: A report from a pros..." RTHC-03455. Retrieved from https://rethinkthc.com/research/ricci-2021-cannabis-use-disorder-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.