Neurodevelopmental models regard impulsivity as a central risk factor for adolescent substance use. However, the practical utility of impulsivity in predicting substance use is complicated by variability among measures that encompass multiple methods and theoretical domains. Prior research has been constrained by cross-sectional designs, small sample sizes, and/or the use of a narrow subset of impulsivity measures.

Leveraging the ABCD dataset (n = 11,868), we identified and replicated correlations among impulsivity measures and assessed their prospective longitudinal and concurrent predictive utility regarding adolescent substance use outcomes before 15 years old. We then used simulation to inform how associations between impulsivity and substance use vary across sampling strategies (population vs. high-risk cohorts) and sample sizes.

Correlations between questionnaire and behavioral measures of impulsivity were small, and questionnaires significantly outperformed behavioral measures in predicting substance use initiation, largely due to the contribution of the CBCL externalizing scale. Predictions of substance use based on impulsivity were statistically detectable but small according to clinical standards (AUCs 0.6–0.76), exhibiting sensitivity to sample size and base rate of substance use, and thus, poor absolute predictive performance. Large samples (n > 1,000) were needed to achieve adequate power for impulsivity measures to predict substance use initiation.

These results support a significant but small contribution of impulsivity in predicting the onset of early adolescent substance use, indicating that these factors alone are insufficient for clinically deployable prediction. In community samples, large sample sizes are needed for reproducible impulsivity prediction of adolescent substance use.

Impulsivity is among the strongest correlates of substance involvement (i.e. a broad continuum of substance-related behaviors), and distinct domains (e.g. sensation seeking [SS] and urgency) are differentially correlated, phenotypically and genetically, with unique substance involvement stages. Examining whether polygenic influences for distinct impulsivity domains are differentially predictive of early substance use initiation – a major risk factor for later problematic use – may improve our understanding of the role of impulsivity in addiction etiology.

Data collected from participants of genetically inferred European ancestry enrolled in the Adolescent Brain Cognitive Development StudySM (n = 4,808) were used to estimate associations between polygenic scores (PGSs) for UPPS-P impulsivity domains (i.e. SS, lack of premeditation [LPREMED]/perseverance [LPERSEV], and negative/positive urgency [NU/PU]) and substance (i.e. any, alcohol, nicotine, and cannabis) use initiation by age 15 years. Mediation models examined whether child impulsivity (ages 9–11 years) mediated links between PGSs and substance use initiation.

SS-PGS was significantly associated with any substance and alcohol use initiation (odds ratio [ORs] > 1.10, psFDR < 0.05). LPERSEV and NU/PU PGSs were nominally associated with alcohol and nicotine use initiation, respectively (ORs > 1.06, ps < 0.05, psFDR > 0.05). No significant associations were observed for LPREMED-PGS or cannabis use initiation. Measured impulsivity domains accounted for 5–9% of associations between UPPS-P PGSs and substance use initiation.

Genetic influences for distinct impulsivity domains have differential associations with early substance use initiation, with SS showing the most robust associations, highlighting valuable etiological insight into the earliest stages of substance involvement that may be leveraged to improve prevention and intervention strategies.