Executive Functioning in Preschoolers with ADHD: The Roles of Disruptive Behavior Disorders and Callous-Unemotional Behaviors

Objective To explore how comorbidities associated with attention-deficit/hyperactivity disorder (ADHD) during early childhood, such as disruptive behavior disorder (DBD) and/or the presence of callous-unemotional behaviors (CU), relate to executive functioning (EF).Method Participants were 323 young children (68.7% boys; Mage = 5.47, SD = 0.77, 81.1% Latinx) with ADHD (n = 46), ADHD+DBD (n = 129), and typically developing (TD; n = 148). Parent/teacher ratings of ADHD, DBD symptoms, and CU were collected at baseline along with a multimodal assessment of EF, including tasks and parent/teacher ratings.Results Univariate analyses of covariance (ANCOVAs) indicated that while children diagnosed with ADHD and ADHD+DBD have worse EF deficits than TD children (Cohen’s d’s range from 0.34–2.35), they do not differ from each other. Regression analyses showed that parent-/teacher-reported ADHD symptoms were most strongly associated with EF deficits (task-based and parent/teacher reports; β range from −0.43 to 1.00). CU also related to EF across two tasks and parent-/teacher-rated EF problems (β range −0.15 to 0.16).Conclusions Young children with ADHD have the most EF deficits, regardless of DBD comorbidity. The presence of CU does appear to contribute to worse EF, even when accounting for ADHD and DBD symptomology. Future work should examine whether longitudinal changes in CU (either through development or intervention) correspond to changes in EF.