The predictive value of brief measures of externalizing behavior and internalizing problems in young people receiving substance use treatment: A secondary analysis

Identifying people at risk of poor outcomes following treatment for substance use disorders is important for developing tailored services. The aim of this study was to test whether a brief measure of internalizing and externalizing behavior could identify young adults at high risk of psychiatric care episodes and criminal offending up to four years after enrolment in treatment for substance use disorder. Clients aged 15–25 years from a randomized multicenter study were included (N = 457). At baseline, all completed the YouthMap12 screener, a measure of internalizing symptoms (IP6) and externalizing problems (EP6). We used accelerated failure time regression to assess time to psychiatric care and criminal offending, adjusting for baseline occurrence, gender, age, treatment group, and uptake area. Youden’s J was used to assess optimal cut-points for risk of events. The IP6 was associated with shorter time to psychiatric care following treatment enrolment (beta = −0.71, 95% confidence interval [CI] = −0.94 to −0.48; adjusted beta = −0.45, 95% CI = −0.66 to −0.25). The EP6 was associated with shorter time to criminal offending, coefficient = −0.32, 95% CI = −0.44 to −0.19; adjusted coefficient = −0.18, 95% CI = −0.30 to −0.06). Optimal cut-points were two or more for the IP6 and three or more for the EP6. The IP6 and the EP6, two simple and easily administered instruments, can identify young adults who are at an increased risk of future criminal offending or in need of psychiatric care. The findings lend support to using the 12-item YouthMap, as it identifies relevant risks, is compatible with local service delivery needs, and is theoretically and empirically supported.