title: Trait Impulsivity and the Externalizing Spectrum.
abstract: This article reviews evidence that trait impulsivity-expressed early in life as the hyperactive-impulsive and combined presentations of attention-deficit/hyperactivity disorder (ADHD)-is a bottom-up, subcortically mediated vulnerability to all externalizing disorders. This vulnerability arises from deficient mesolimbic dopamine responding, which imbues psychological states (irritability, discontentment) that motivate excessive approach behavior (hyperactivity, impulsivity). Through complex interactions with (a) aversive motivational states that arise from largely independent subcortical systems, (b) emotion regulatory mechanisms that arise from top-down, cortical modulation of subcortical neural function, and (c) environmental risk factors that shape and maintain emotion dysregulation, trait impulsivity confers vulnerability to increasingly severe externalizing behaviors across development. This perspective highlights the importance of identifying transdiagnostic neural vulnerabilities to psychopathology; dovetails with the hierarchical, latent structure of psychopathology; and suggests that progression along the externalizing spectrum is an ontogenic process whereby a common, multifactorially inherited trait interacts with endogenous and exogenous influences to yield increasingly intractable externalizing behaviors across development.
authors.affiliation: Department of Psychology, The Ohio State University, Columbus, Ohio 43210; email: beauchaine.1@osu.edu , zisner.1@osu.edu.
authors.forename: Theodore P
authors.initials: TP
authors.lastname: Beauchaine
authors.affiliation: Department of Psychology, The Ohio State University, Columbus, Ohio 43210; email: beauchaine.1@osu.edu , zisner.1@osu.edu.
authors.forename: Aimee R
authors.initials: AR
authors.lastname: Zisner
authors.affiliation: Department of Psychiatry, University of Texas Health Science Center, San Antonio, Texas 78229; email: sauder@uthscsa.edu.
authors.forename: Colin L
authors.initials: CL
authors.lastname: Sauder
mesh_terms: D019958:Attention Deficit and Disruptive Behavior Disorders / Q000209:etiology / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D007175:Impulsive Behavior / Q000502:physiology*
keywords: anxiety; dopamine; emotion dysregulation; externalizing spectrum; impulsivity; ontogenic process