High five! – the big 5 personality traits, locus of control, and impulsivity and their relationship to substance use in a large cohort of university students in Berlin

Abstract Background Research suggests that university students are at high risk of using licit and illicit substances and that there has been an increase over the last decade in substance use among university students in Berlin, Germany. The present study aims to investigate the relationship between personality and substance use among university students in the city of Berlin. Method A sample of 8778 students from 17 Berlin universities completed an online questionnaire. Short versions of the Big Five Inventory and the Barratt Impulsivity Scale as well as the SOEP-scale (German socioeconomic panel) for the concept of locus of control were used to assess personality traits. Four different user groups and six specific substances were studied using multinomial logistic and logistic regression models. Results Participants regularly using substances scored higher on impulsivity and openness and lower on conscientiousness compared to the other user groups. Further, they scored higher on extraversion and external locus of control compared to participants not using substances or exclusively drinking alcohol. Out of the personality dimensions examined, the relationship between substance use and impulsivity was strongest and had the highest effect size (medium) in our sample. Conclusions Despite increasing prevalence among the high-risk group of university students in Berlin, universities have not yet sufficiently adopted prevention programs. These programs should be adapted to meet the needs of the target group which may be complemented with the findings of the study (e.g. emotional regulation training and goal management training).