Indicators of Impulsivity in Routine Clinical Assessment of Adult ADHD

Impulsivity in adult attention-deficit/hyperactivity disorder (ADHD) represents a multidimensional construct rather than a unitary trait. This study examined a proposed three-factor model of impulsivity comprising (a) self-reported impulsive behavior (Barratt Impulsiveness Scale), (b) commission errors, and (c) reaction time measures from neuropsychological tests in 654 adults undergoing routine clinical assessment of adult ADHD. Using confirmatory factor analyses on split subsamples, we found consistent support for the proposed three-factor structure, whereas the network analysis favored a two-group conceptualization that separates performance-based from self-report-based measures. Self-reported impulsivity demonstrated the highest severity levels, followed by commission errors, with reaction times being least affected. Demographic and clinical characteristics significantly predicted self-reports and commission error measures but not reaction times. The results emphasize the importance of interpreting self-reports independently of performance-based tests. The coherence between commission errors and reaction time variables across tasks of related constructs suggests that administering multiple tasks may yield redundant information in the clinical assessment of impulsivity.