Callous-unemotional traits in Chinese preschool children with attention-deficit/hyperactivity disorder

Background Children with early onset of Callous-Unemotional (CU) traits are at a higher risk for long-term, persistent psychosocial problems. The current study aimed to explore the characteristics of CU in preschool children with Attention Deficit Hyperactivity Disorder (ADHD) and the diagnostic significance of CU traits in ADHD. Methods A total of 176 preschool children (89 with ADHD and 87 Typically Developing Children [TDC]) aged 4-5 years old were recruited to the study. The participants were assessed for CU traits, emotional and behavioral problems, and how their executive functioning was associated with ADHD using multiple assessment scales. Multiple linear regression analysis was performed to assess the incremental validity of the Inventory of Callous-Unemotional Traits (ICU), adjusting for possible covariates by child's sex, conduct problems, and oppositional defiant symptoms. Results The results showed that there was a significant difference of ICU scores between the ADHD and TDC groups (F = 30.12, P < 0.001). In terms of callousness, ADHD + Oppositional Defiant Disorder (ODD) group showed a significant high score, and the ADHD only group scored significantly higher than the TDC group (F = 20.42, P < 0.001). The ICU was negatively associated with the prosocial behaviour subscale (gamma = - 0.57, P < 0.01) and showed low to moderate positive correlations with emotional and behavioural problems, as well as executive function (gamma = 0.24-0.67, P < 0.05). The ICU scores explained 6% of the incremental validity in ADHD symptoms. The diagnostic value of the ICU for ADHD was medium and acceptable. Conclusions The current study indicated that early identification of CU traits may help clinicians better understand symptoms and behavioural problems in children with ADHD. CU traits therefore could be considered as a useful assessment tool for ADHD.