Correlates and trajectories of alcohol and cannabis misuse in the early phase of psychosis: Do we need substance specific interventions?

BACKGROUND

Substance use disorder (SUD) is common in first-episode psychosis (FEP) and linked to poorer clinical and functional outcomes. Previous studies were mostly cross-sectional or short-term, leaving the longitudinal impact of SUD course unclear. This study aimed to (A) group patients based on different trajectories of cannabis use disorder (CUD) and alcohol use disorder (AUD) over 3-year follow-up and to (B) examine associations with baseline characteristics and clinical outcomes.

METHODS

We included 467 FEP patients enrolled in a 3-year early intervention program. Latent class analysis found subgroups based on cannabis and alcohol use trajectories. Groups were then compared using logistic regressions and mixed-model repeated measures (MMRM), adjusting for relevant confounders.

RESULTS

We found different evolution of AUD and CUD: alcohol users tended to maintain consumption over time, while a subset of cannabis users reduced their consumption. Persistent alcohol users showed worst baseline characteristics and outcomes if compared to abstinent or light consumers. Concerning cannabis, MMRM analyses showed that abstinent or light users consistently had better symptom evolution compared to persistent or decreased users. However, the decreased group showed higher hospitalization rates than the other groups. They also showed gradual improvement in negative symptoms, reaching similar levels to abstinent users by the end of the program.

CONCLUSIONS

This study outlines the distinct evolution of alcohol and cannabis consumption in FEP patients, suggesting the importance of tailored therapeutic approaches. Consistently with existing literature, abstinence or light use seems to be beneficial, while reducing cannabis use appears to offer a limited clinical improvement.