Abstract

Background: Callous-unemotional (CU) traits are associated with lower treatment engagement, more severe symptoms, and worse treatment outcome for youths with disruptive behaviours (Hawes et al., 2014; Perlstein et al., 2023). Another condition that is often comorbid with disruptive behaviour is attention-deficit/hyperactivity disorder (ADHD) (Graziano et al., 2017). Preliminary research suggests that nearly half of youths with ADHD have CU traits. CU traits may similarly predict lower treatment engagement and response for youths with ADHD, but research is lacking. This study examines associations between CU traits and post-treatment ADHD symptoms, reliable improvement, and treatment engagement for youths. Method: Data were drawn from a previous study examining the effectiveness of summer treatments for youths with ADHD. Seventy-two youths (Mage = 13.04) were assessed at baseline, end of summer treatment, and end of academic year. Multiple and binary logistic regression analyses assessed if CU traits predicted 1) post-treatment ADHD symptoms, 2) reliable clinical improvement in ADHD symptoms, and 3) treatment engagement. Results: CU traits did not significantly predict parent- (b = -0.003, p =.509) or teacher-rated (b = 0.020, p =.712) post-treatment ADHD symptoms. Additionally, only parent-rated CU traits positively predicted reliable improvement from baseline to end of summer (b = 0.051, OR = 1.053, p =.048). Finally, CU traits were not a significant predictor of treatment engagement (b = -0.002, p =.663). Implications: Overall, the research contributes to understanding of adolescents with ADHD and CU traits and their responsiveness in summer treatment programs.