Executive function assessment and adult attention-deficit/hyperactivity disorder: tasks versus ratings on the Barkley deficits in executive functioning scale.

Adults with attention-deficit/hyperactivity disorder (ADHD) exhibit variable impairments on executive function (EF) tasks. Due to this variability, ratings of EF (rather than tasks) have been proposed as an alternative method that better captures symptom severity and impairment among adults with ADHD. However, few studies have jointly examined performance across multiple neuropsychological domains and EF ratings as predictors of severity and impairment among adults with ADHD. Adults (N = 273) ages 18-38 years (M = 22.6 years, 55.3% male, 62.2% with ADHD) completed a comprehensive diagnostic and neurocognitive assessment, which included self and informant ratings of ADHD symptom severity and EF and tasks of arousal/activation, response inhibition, set shifting, interference control, and working memory. Hierarchical linear regression models indicated that tasks of arousal/activation and response inhibition uniquely predicted ADHD symptom dimensions and related impairments. Over and above EF task performance, EF ratings of time management significantly predicted increased inattention (β = .209, p < .001, ΔR² = 3.9%), whereas ratings of restraint predicted increased hyperactivity/impulsivity (β = .259, p < .001, ΔR² = 6.4%). Furthermore, EF ratings of time management, restraint, and emotion regulation incrementally accounted for variance in relationship, professional, and daily living impairments over and above EF task performance (ΔR² range = 1.7-7.7%). Results may help refine neurobiological theories and assessment of adult ADHD.