Cannabis and Other Substance Use, Experiences of Ethnoracial Discrimination, and Psychotic-Like Experiences

Cannabis use has been linked to increased positive psychotic-like experiences (PLEs) and found to act additively with stressful/traumatic events to increase risk for psychosis. Emerging evidence suggests that experiencing ethnoracial discrimination is a chronic stressor associated with increased substance use and positive PLEs. We hypothesized that ethnoracial discrimination would be associated with increased positive PLEs through the indirect effect of increased cannabis use.

Community individuals (n = 7,429) aged 16-30 ascertained from the Multi-site Assessment of Psychosis-risk (MAP) study completed self-report assessments of ethnoracial discrimination, cannabis and substance use, and positive PLEs. Statistical analyses using an indirect effects framework examined direct effects from ethnoracial discrimination to specific positive PLEs (non-persecutory ideation, persecution ideation, and perceptual abnormalities), and indirect effects through cannabis use. To test the specificity of cannabis, supplementary analyses examined indirect effects through other substance.

Across Asian, Black, Hispanic, and non-Hispanic White participants, significant direct effects were found from ethnoracial discrimination to each positive PLE (all p < 0.01). Significant indirect effects were found through cannabis use and through other substance use among Asian, Black, and Hispanic individuals, and via other substance use in non-Hispanic White individuals (all 95% CIs excluded zero).

Results suggest that any substance use, including but not limited to cannabis use, may be a common pathway by which exposure to stressful experiences of ethnoracial discrimination may contribute to increased positive PLEs. Findings have implications for targeting substance use in individuals who may be at increased risk for psychotic experiences and who have experienced ethnoracial discrimination.