Effects of Brief Interventions on Internalizing Symptoms and Substance Use in Youth: A Systematic Review.

Internalizing problems (e.g., depression, anxiety) and substance use are common among young people and often co-occur. However, youths face myriad barriers to access needed treatment, and existing evidence-based interventions tend to focus on internalizing problems or substance use, rather than both simultaneously. Brief interventions that target both problems may, therefore, be an efficient and accessible resource for alleviating youth difficulties; however, this possibility has been insufficiently evaluated. This systematic review evaluated the intervention characteristics and quality of six studies spanning 2015 to 2019 that examined intervention effects on internalizing and substance use outcomes. Based on independent calculations and author reports (respectively), 3-4 interventions significantly reduced youth internalizing symptoms; 3-5 reduced youth substance use; and 2-3 reduced symptoms in both domains. All six interventions identified substance use as a primary target. Four interventions were administered by interventionists to youths in inpatient, outpatient, primary care, or school settings. The remaining two studies delivered content through voicemail messages or an online design. Interventions ranged from ~ 15 to 240 min. Results highlight the sparsity and heterogeneity of youth-focused brief interventions that have evaluated program effects on both internalizing problems and substance use outcomes, suggesting a clear need for integrated supports that are also designed for accessibility. Future investigations of brief youth-focused interventions should assess program effects on both internalizing and substance use outcomes; examine mechanisms driving the varied efficacy of identified interventions; and create, refine, and test interventions with potential to address co-occurring internalizing problems and substance use in young people.