Cannabis Users in Early Psychosis Who Reduced Use Still Had Worse Outcomes Than Abstainers

Alcohol users tended to maintain consumption over time, while some cannabis users reduced their use. Persistent alcohol users had the worst baseline characteristics and outcomes. Abstinent or light cannabis users consistently had better symptom outcomes than persistent or decreased users. However, cannabis decreasers showed higher hospitalization rates than other groups, though their negative symptoms gradually improved to levels similar to abstinent users by program end.

3-year early intervention program study of 467 first-episode psychosis patients. Latent class analysis identified cannabis and alcohol use trajectory subgroups. Logistic regressions and mixed-model repeated measures compared baseline characteristics and clinical outcomes across trajectory groups.

The finding that reducing cannabis use improved some but not all outcomes suggests that simply cutting back may not be sufficient for optimal recovery in first-episode psychosis, and that the trajectory of use matters for treatment planning.

This study highlights that alcohol and cannabis use have distinct trajectories and impacts in early psychosis, suggesting that substance-specific interventions may be more effective than generic substance use treatment in this population.

Observational design limits causal inference. Self-reported substance use. Latent class analysis results are sample-dependent. Cannot determine if symptom changes caused use changes or vice versa. Single intervention program setting.