Behavioral, personality, and temperamental characteristics predict escalating alcohol and cannabis use and problems during the first-year of college.

Recent studies suggest that behavioral and temperament characteristics provide insight into individual differences in drug use behaviors, but few studies have described their prospective associations. We investigated how temperament and behavioral characteristics associate with drinking and cannabis use prior to and during the start of college. Participants were 252 college students (175 females, mean age = 18.56, SD = .38) from the MAPme Project. Behavioral and temperamental characteristics were assessed using the Transmissible Liability Index [TLI]) in orer to predict alcohol and cannabis use and problems assessed using the Alcohol, Smoking and Substance Involvementprior scale. Linear and logistic regression was used to assess associations at and across each wave of assessment. Roughly 61% of students used alcohol and 27% used cannabis in the three months prior to starting college. Higher TLI scores were associated with earlier age of alcohol and tobacco initiation, greater odds of drinking alcohol (3.41 [95% CI = 1.90,6.12]) and smoking cannabis (3.79 [7.86,7.73]) during the first semester, and more more severe alcohol problems at college (β = 0.31 [0.09,0.56]). The findings illuminate the sensitivity and utility of temperament and behavioral characteristics in forecasting risky behaviors, highlighting an opportunity to better structure campus drug prevention.