From Impulse to Action? Cognitive Mechanisms of Impulsivity-Related Risk for Externalizing Behavior

Trait impulsivity is an established risk factor for externalizing behavior problems in adolescence, but little is understood about the cognitive mechanisms involved. Negative automatic thoughts are associated with externalizing behaviors and impulsivity is associated with less cognitive reappraisal. This study sought to adapt the bioSocial Cognitive Theory (bSCT) of impulsivity and substance use (an externalizing behavior) for externalizing behavior in general. It was predicted that only the component of impulsivity characterized by lack of forethought (rash impulsiveness; RI) would be associated with (non-substance use-related) externalizing behaviors, not reward sensitivity/drive. Further, this association would be mediated by negative automatic thoughts. Participants were 404 (226 female, 63%) adolescents from 6 high schools across South-East Queensland (age = 13-17 years, mean age = 14.97 years, SD = 0.65 years) of mostly Australian/New Zealand (76%) or European (11%) descent. Participants completed self-report measures of impulsivity, negative automatic thoughts, and externalizing behaviors. Path analysis revealed that, as predicted, only RI was uniquely associated with negative automatic thoughts and externalizing behaviors. However, only negative automatic thoughts centered around hostility mediated the positive association between RI and externalizing behaviors, with the indirect mediation effect being smaller than the direct association. In contrast to substance use, only one component of impulsivity, RI, was associated with general adolescent externalizing behavior. Hostile automatic thoughts may be an important mechanism of risk, supporting a role for cognitive-behavioral interventions. Other biopsychosocial mechanisms are clearly involved and the bSCT may provide a useful framework to guide future research.