Screening Substance-Naive Children for Risk of Frequent/Heavy Substance Use in Young Adulthood: A 17-Year Prospective, National Study

Objective: There is no externally validated instrument for predicting which substance-naive children will show frequent/heavy substance use (SU) in young adulthood. This study evaluated whether an instrument previously shown to predict SU outcomes in mid-adolescence could also predict SU outcomes in young adulthood. Method: The Loeber Risk Score (LRS) is a 5-item, parent-completed screener indexing SU risk in substance-naive children. We evaluated the predictive performance of the LRS in a nationally-representative longitudinal birth cohort (N = 4,898, 48% female). Parents completed the LRS when the child was ~5 and ~9 years old and substance-naive. Subsequently, youth reported their SU at age ~22 years old. Results: The LRS at age 9 predicted several outcomes at age 22 (ps<0.05): daily cigarette use (AUROCs=0.71-0.75), cannabis use ≥3x week (AUROC=0.59), and vaping ≥3x week (AUROC=0.55), and receipt of treatment for an alcohol/drug problem (AUROC=0.60). Performance was no better than chance for alcohol outcomes (AUROCs=0.47-0.50). Children with LRS scores ≥2 were 1.3-2.0 times more likely to display frequent/heavy substance use outcomes. There were no consistent performance differences when the LRS was completed at age 5 vs. age 9 or by child’s sex, race, or ethnicity. Conclusion: The LRS is now the only externally validated instrument for indexing risk of frequent/heavy SU in young adulthood among substance-naive children. However, accuracy is modest, and the instrument does not predict alcohol use outcomes. Better screeners are needed.