Abstract
BACKGROUND: Young children with attention-deficit/hyperactivity disorder (ADHD) and comorbid disruptive behavior disorders (DBD) exhibit significant impairments across functional domains, which are compounded by co-occurring callous-unemotional (CU) behaviors. OBJECTIVE: This study examined the impact of the Summer Treatment Program for pre-kindergarteners (STP-PreK) on reducing callous-unemotional (CU) behaviors in children with and without ADHD and DBD. METHOD: This study utilized a multi-informant approach to examine the change in CU behaviors in response to the STP-PreK via parent and teacher report across three time points. The current sample included three groups based on diagnostic status (68.7% boys; mean age = 5.47, SD = 0.77, 81.4% Latinx): ADHD Only (n = 46), ADHD+DBD (n = 129), and typically developing (TD; n = 148). RESULTS: Linear mixed models revealed significant initial differences in CU scores, with ADHD+DBD displaying higher CU scores, followed by ADHD Only, and then TD. Per teacher report, both ADHD groups experienced substantial decrease in CU behaviors over time, with moderate effect sizes (Cohen's d = .67-.76). At the 1-year follow-up, children in the ADHD Only group no longer significantly differed from TD peers, while the ADHD+DBD group continued to exhibit significantly higher CU scores. CONCLUSION: The findings suggest that the STP-PreK has a positive impact on reducing CU behaviors in children with ADHD during the transition to kindergarten or first grade. Understanding and addressing CU traits in early childhood may contribute to improved treatment outcomes and long-term social-emotional development.