Impulse Control in Focus: Rethinking Impulsivity in Youth With Attention-Deficit/Hyperactivity Disorder

Objective Impulsivity, a key symptom in attention-deficit/hyperactivity disorder (ADHD), is related to maladaptive outcomes longitudinally. Yet relatively little is known about how impulsivity manifests among children with the ADHD primarily inattentive presentation. We sought to address this gap by investigating impulsivity symptoms across all ADHD subtypes and in youth without ADHD. We also examined the association between ADHD symptoms at baseline and maladaptive outcomes measured cumulatively over 4 years. Method We examined impulsivity symptoms and maladaptive outcomes measured longitudinally among 5,059 youth with complete diagnostic and symptom data, 9 to 10 years of age, from the Adolescent Brain Cognitive Development℠ (ABCD) Study. Results Youth with the ADHD inattentive presentation demonstrated elevated impulsivity relative to typically developing youth across self (Cohen d = 0.489, 95% CI=0.40, 0.58, p < .00001) and parent reports ( d = 1.40, 95% CI=1.31, 1.50, p < .00001) as well as decreased performance relative to typically developing youth on measures of impulsivity control (flanker: d = –0.251, 95% CI=– 0.35, –0.16, p < .0001; stop signal task: d = –0.276, 95% CI=– 0.38, –0.17, p < .00001). Among youth with the inattentive presentation, impulsivity measured at study baseline was associated with increased risk for maladaptive outcomes after controlling for hyperactivity and inattentive symptoms. Conclusion Impulsivity symptoms among youth with the inattentive ADHD presentation are higher than traditionally conceived. Longitudinal associations between impulsivity and maladaptive outcomes underscore the clinical import of elevated impulsivity symptoms in youth with the inattentive presentation. We highlight the importance of classifying impulsivity symptoms independently of hyperactivity symptoms to facilitate accurate identification of individualized symptom profiles for the purpose of personalized treatment planning and risk evaluation, and to advance future research. Plain language summary Youth with attention-deficit/hyperactivity disorder (ADHD) may have difficulty controlling impulses. This study examined several types of impulsivity in a diverse sample of youth with ADHD aged 9 to 10 years from the Adolescent Brain Cognitive Development℠ (ABCD) Study. The authors found that impulsivity symptoms among youth with ADHD inattentive presentation were higher than previously thought. Impulsivity symptoms were associated with aggression and substance use, highlighting the importance of accurately identifying individualized symptom profiles to personalize risk evaluation and treatment planning.