Impulsivity traits moderate the longitudinal association between mental health and hazardous cannabis use in emerging adults

Introduction The aim of this study was to examine longitudinal changes in past-month cannabis use and hazardous cannabis use over 1 year in emerging adults and to examine the prospective associations between changes in depression, anxiety, stress and hazardous cannabis use, using age, sex and impulsivity as potential moderators. Methods Participants were 2762 college students (aged 18-25) who were surveyed three times over the course of a year (T1: September-November 2021; T2: March-May 2022; and T3: September-November 2022). Structural equation modelling and semi-parametric mixed-effects repeated measures models were used to examine the prospective associations between depression, anxiety, stress and hazardous cannabis use, moderated by time-variant (impulsivity trait and age) and time-invariant (sex at birth) variables. Results The prevalence of past-month cannabis use was 11.5% at T1, 3.5% at T2 and 9.1% at T3. Autoregressive effects suggested that participants with elevated symptoms of depression, anxiety and stress at T2 tended to inform on similar impairment at T3. Cross-lagged relationships were found for anxiety at T2 and hazardous cannabis use at T3, and for hazardous cannabis use at T2 and stress at T3. Increases in emotional variables were indirectly associated with a higher risk of hazardous cannabis use through impulsivity traits. Discussion and Conclusions Cannabis users reported more problems in the face of worsened mental health and negative/positive urgency. Effective interventions should be framed under a transdiagnostic approach that targets emotional regulation.