Impulsivity Dimensionality and Substance Use Risk: Young Adults Vs. Adults

Introduction: Defined as an individual’s reduced ability to self-regulate and responsibly govern impulses and urges, impulsivity is increasingly acknowledged as a multidimensional construct.  Although impulsivity is regarded as multifaceted trait, two domains of impulsivity have been particularly associated with drug use: impulsive personality traits and delay discounting.  Empirical evidence on the factor structure of impulsivity assessed using multiple methods can provide information that will orient prevention program development. Thus, needed is research that will (a) evaluate the construct validity of impulsivity among young adults compared to adults and (b) test the multi-factorial solution’s predictive validity of substance use in young adult compared to adults.

Methods: Data from 1,070 young adults (age range: 18-25) and 181 adults (age range: 25-40) were obtained from two urban centers in the U.S.  Impulsivity was assess by a multi-method approach including self-report (UPPS), choice task (delayed reward discounting), and impulsive action (Go-no-go task) as well as the NEO measure of the five factor model of personality. Substance use risk was measured using the AUDIT (Alcohol Use Disorders Identification Test) and DUDIT (Drug Use Disorders Identification Test).

Results: Confirmatory factor analyses supported a three factor model that included Trait, Action, and Choice factors. Compared to one and two factors, the three factor model solution showed a significant improvement in model fit (Dχ²(14) =1438.26); χ²(87) =1172.04; SRMR=0.06; CFI=0.93; RMSEA=0.06). Multiple group analyses were used to evaluate measurement invariance in loadings, intercepts and error variances. Results indicated support for metric and scalar measurement invariance across the two age groups supporting the hypothesis that the tripartite model of impulsivity is measured equivalently in young adults and adults. Lastly, SEM output revealed that controlling for demographic differences, the AUDIT was significantly associated with the impulsivity factors of Choice and Trait but not with Action, whereas the DUDIT was exclusively associated with the Trait factor.  Compared to young adults, adults’ levels of impulsive action showed elevated risk for drug use.

Conclusion: Findings support the multidimensional tripartite structure of impulsivity among young adults and adults. Impulsive choice and trait are strong cognitive risk markers for drug use across age. Impulsive action emerges as a risk marker for drug use in adults only, suggestive of its potential developmental course in the progression of addiction. The study informs preventive interventions by documenting the clinical utility of impulsivity as a multidimensional construct with differential risk for substance use.