Functional recovery trajectories in cannabis-induced first-episode psychosis: The role of dissociative symptoms in the discrepancy between symptomatic improvement and functional outcomes.
Valerio Ricci, Andrea Paggi, Giovanni Martinotti, Giuseppe Maina
Psychiatry Research May 25, 2026 DOI: 10.1016/j.psychres.2026.117240 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Prospective cohort study Peer reviewed |
|---|---|
| Sample size | 72 |
| Population | Patients meeting DSM-5 criteria for cannabis-induced psychotic disorder |
| Duration | 24-month follow-up |
| Topics | Cannabis |
| Keywords | Cannabis-induced psychosis Depersonalization Dissociation First-episode psychosis Functional recovery |
| Key findings | Dissociative symptoms, particularly depersonalization and derealization, independently predict functional recovery trajectories in cannabis-induced first-episode psychosis, mediating 35% of cannabis's effect on functional outcomes. |
Abstract
Functional recovery in cannabis-induced first-episode psychosis (FEP) remains incompletely understood. Dissociative symptoms, frequently associated with cannabis use, may represent a key but underexplored determinant of functional trajectories. This prospective cohort study followed 72 patients meeting DSM-5 criteria for cannabis-induced psychotic disorder over 24 months. Functional recovery trajectories were identified using growth mixture modeling (GMM) of GAF scores. Mediation analyses examined whether dissociation (DES) mediates the relationship between continued cannabis use and functional outcomes. GMM identified three trajectories: Rapid Recovery (34.7%, n = 25; GAF +29.1 points), Gradual Recovery (40.3%, n = 29; GAF +15.7 points), and Persistent Impairment (25.0%, n = 18; GAF +4.7 points). These trajectory findings should be considered exploratory given the modest sample size. Symptom-function discrepancy was observed in 31.9% of patients, characterized by significant PANSS reduction without functional gains and elevated baseline dissociation (DES=33.8 vs. 18.1, p < 0.001). Baseline dissociation independently predicted trajectory membership (OR=3.24 per SD, p < 0.001), with depersonalization/derealization showing the strongest associations. Dissociation mediated 35% of cannabis's effect on functional outcomes (β=-0.15, 95%CI [-0.25,-0.06]); combined with depression and hopelessness, psychological mediators accounted for 76% of total effect. A high-risk subgroup (elevated dissociation, depression, continued cannabis use; 22%) showed minimal improvement despite treatment. Dissociative symptoms represent powerful independent predictors of functional recovery in cannabis-induced FEP, partially independent of psychotic symptom resolution. Routine dissociation assessment and targeted interventions alongside cannabis cessation may optimize functional outcomes in this population.
Comparable studies
Other observational and cohort studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population | 2009 | Case-control study | n = 454 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people | 2000 | Observational | |
| Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline | 2011 | Observational cohort | n = 1,923 |
| Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... | 2005 | Observational cohort | n = 535 |
Citations in the library
Cites 12
- Duration of Untreated Disorder and Cannabis Use: An Observational Study on a Cohort of Young Italian Patients Experiencing Psychotic Experiences and Dissociative Symptoms International Journal of Environmental Research and Public Health November 30, 2021
- The impact of childhood trauma and cannabis use on paranoia: a structural equation model approach. Psychological Medicine August 8, 2025
- The Resurgence of Exogenous Psychosis: A Phenomenological Examination of Substance-Induced Psychopathology. The Journal of Nervous and Mental Disease September 1, 2024
- First episode psychosis with and without the use of cannabis and synthetic cannabinoids: Psychopathology, global functioning and suicidal ideation and antipsychotic effectiveness. Psychiatry Research 2023
- Cannabis induced psychosis: a systematic review on the role of genetic polymorphisms. Pharmacological Research May 1, 2022
and 7 more in the library