Long-term effects of brief substance use interventions for mandated college students: Sleeper effects of an in-person personal feedback intervention

Background: It is known that brief interventions for mandated college students decrease alcohol use and/or related problems in the short term. However, none of the existing studies has followed students' past 6 months. Therefore, we compared the long-term efficacy of 2 brief substance use feedback interventions for mandated college students. Methods: We followed up mandated students (N=348) who were randomly assigned to either a brief motivational interview (BMI; n=180) or a written feedback-only (WF; n=168) intervention at 4 months and 15 months postintervention. Results: Long-term follow-up data revealed that students, at the aggregate level, decreased their peak blood alcohol concentration (BAC) levels, number of drinks per week, and number of alcohol-related problems at 15 months postintervention compared with their baseline levels. With the exception of peak BAC, the observed long-term reduction was mainly due to the positive change among students who received the BMI intervention. Students in the BMI intervention showed significantly lower levels of alcohol-related problems at 15 months than those in the WF intervention. The BMI intervention more effectively reduced within-individual alcohol-related problems during the initial 4 months, and more successfully curbed the subsequent increase in alcohol use frequency and number of drinks per week during the 11 months between the 2 follow-up assessments. Conclusions: The results suggest that brief substance use interventions reduce the riskiest type of alcohol use (e.g., peak BAC) among mandated college students over the long term, and that sleeper effects of in-person personal feedback interventions (PFIs) exist. In-person PFIs in the context of a motivational interview may be more efficacious in the long term than written feedback-only interventions for mandated students. Future studies comparing interventions for college students should extend follow-up for longer periods of time.