The separate and joint effects of recent interpersonal abuse and cannabis use on psychotic experiences: findings from students in higher education in the United States

Background: Various forms of interpersonal abuse (e.g., physical, emotional, sexual) and cannabis use across the lifespan have both been known to increase odds of psychotic experiences; however, there have been few studies examining their separate and joint effects in the United States. Methods: We analyzed data from the Healthy Minds Study (2020–2021) and used multivariable logistic regression and interaction contrast ratios to assess separate and joint effects of interpersonal abuse (past 12 months) and cannabis use (past 30 days) on psychotic experiences (past 12 months). Results: Students who only used cannabis had significantly greater odds of psychotic experiences (aOR: 1.70; 95% CI 1.58–1.82), as well as those who only experienced interpersonal abuse (aOR: 2.40; 95% CI 2.25–2.56). However, those who reported both cannabis use and interpersonal abuse had the greatest odds, exceeding the sum of these individual effects (the combined effect aOR: 3.46; 95% CI 3.19–3.76). Conclusions: Recent interpersonal abuse and recent cannabis use both separately and jointly increase odds of having recent psychotic experiences. Future research should continue to examine the potential interactive and additive impact of multiple known exposures to better inform primary and secondary prevention efforts.