Functional recovery trajectories in cannabis-induced first-episode psychosis: The role of dissociative symptoms in the discrepancy between symptomatic improvement and functional outcomes.

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.