Neighborhood deprivation and daily cannabis use independently linked to psychosis rates across Europe

Lower owner-occupancy was independently associated with increased first-episode psychosis incidence (aIRR: 0.76) and non-affective psychosis (aIRR: 0.68). Daily cannabis use prevalence was associated with affective psychosis incidence (aIRR: 1.53). High-potency cannabis use was not independently associated with psychosis incidence after adjustment.

Researchers used incidence data from 14 settings in the EU-GEI study for people aged 18-64. Cannabis use prevalence was estimated from population controls with multiple imputation for missing data. Negative binomial regression modeled psychosis incidence while controlling for population density, age, sex, and migrant/ethnic group.

This is one of the first studies to examine both social deprivation and cannabis use simultaneously as predictors of psychosis incidence across multiple settings. The finding that both factors contribute independently suggests neither alone explains the variation in psychosis rates.

The debate about whether cannabis causes psychosis often overlooks the social context in which cannabis use occurs. This study highlights that neighborhood-level poverty and cannabis use patterns are both relevant, and that public health interventions targeting either factor could potentially reduce psychosis burden.

Ecological study design means individual-level conclusions cannot be drawn. Cannabis use prevalence was estimated from controls, not directly measured in the population. Cross-sectional design limits causal inference. Only 14 settings were included.