Validation of the Short UPPS-P Impulsive Behavior Scale in Danish adolescents

Purpose. The short UPPS-P (SUPPS-P) is a widely used, gold-standard measure capturing five facets of impulsivity, including negative urgency, (lack of) premeditation, (lack of) perseverance, sensation seeking, and positive urgency. However, most validation studies have been conducted in relatively small convenience samples, few utilize multi-wave data, and no formal psychometric evaluation of the SUPPS-P has been conducted in a Danish sample. Procedures. Up to 2,745 adolescents (65.46% female, Mage=16.77 [SD=0.58] at baseline) completed the Danish SUPPS-P, as well as measures of substance use, self-efficacy, well-being, and internalizing symptoms at four timepoints over a 12-month period. Confirmatory factor analysis was conducted to evaluate fit of the established SUPPS-P five-factor structure and test measurement invariance across biological sex. Convergent, discriminant, and predictive validity; internal consistency; and test-retest reliability were evaluated for each subscale. Main Findings. Replicating past studies, a five-factor model best fit the data, but several items loaded weakly on the lack of perseverance and sensation seeking factors. Measurement invariance across biological sex was established. Positive correlations with substance use, negative correlations with self-efficacy and well-being, and subscale-specific correlations with internalizing symptoms supported convergent and discriminant validity. Correlations of baseline SUPPS-P scores with external variables up to 12 months later supported predictive validity. Internal consistency was acceptable for all subscales (ω=0.67-0.81) and moderate intraclass correlation coefficients (ICC=0.51-0.69) supported adequate test-retest reliability. Conclusions. The SUPPS-P is suitable for assessing impulsivity in Danish adolescents over time, though further research is needed to optimize the measure’s psychometric properties in this group.