Objective: This study utilized a multimodal approach to examine emotion dysregulation (ED) in young children with attention-deficit/hyperactivity disorder (ADHD), ADHD + oppositional defiant disorder (ODD), and typically developing (TD) children. Methods: We sought to explore if specific domains of ED (emotion regulation [ER], negativity/lability [ERNL], emotion knowledge/understanding [ERU], and callous-unemotional [CU] behaviors) were uniquely associated with diagnostic classifications. The final sample consisted of 152 children (75% boys; mean age = 5.52, SD = .84, 83.4% Latinx) with the following group composition: ADHD- Only (n = 24), ADHD + ODD (n = 54), and TD (n = 74). Results: Higher levels of ADHD and ODD symptoms, measured continuously, were significantly associated with poorer EREG, greater ERNL, and higher levels of reported CU behaviors. There were no significant associations between ADHD or ODD symptoms on ERU. Using discriminant analyses, we found that parent/teacher reported EREG, ERNL, and CU were significant predictors of diagnostic classification. These ED domains correctly identified 84.7% of preschoolers. The model was most successful in classifying children with ADHD+ODD (92.3%) and TD (93.2%) children; however, the ADHD-Only group was correctly identified only 41.7% of the time. Conclusions: This is the first study to 1) examine multiple domains of ED in a clinical sample of preschool children with and without ADHD and 2) explore the clinical utility of considering ED when assessing for ADHD and ODD. Our findings suggest that measures of ED are particularly helpful for correctly diagnosing ADHD and co-occurring ODD but not necessarily children with ADHD-Only.
