The association between symptom severity and theory of mind impairment in children with attention deficit/hyperactivity disorder

The aim was to investigate the correlation between ADHD symptom severity and impairments in "theory of mind" (ToM) and empathy, and the improvement in these functions following the administration of methylphenidate (MPH). Fifty children aged 6–12 years with ADHD participated in the study. Symptom severity was assessed using the Swanson, Nolan and Pelham Questionnaire-IV (SNAP-IV). ToM performance was assessed using the "ToM test" and the “Faux-Pas Recognition Test”. A significant negative correlation was found between the SNAP-IV Conners index, the oppositional and deportment subscales, and ToM test scores. MPH administration improved ToM scores in a magnitude that was negatively correlated with baseline performance. Additionally, Children with more severe behavioral problems showed greater improvement in ToM following administration of MPH. We conclude that severity of ADHD symptoms, most notably behavioral symptoms, is correlated with deficits in ToM. Administration of MPH improves ToM performance, with the greatest improvement occurring in children with more severe behavioral symptoms.