Impaired Theory of Mind and psychosocial functioning among pediatric patients with Type I versus Type II bipolar disorder.

Deficits in Theory of Mind (ToM) have been documented among pediatric patients with Bipolar Disorder (BD). However, fewer studies have directly examined differences between type I and type II patients and whether or not ToM deficits are related to psychosocial difficulties. Therefore, the aim of this study was to compare type I versus type II pediatric bipolar patients and matched Healthy Controls (HC) on ToM and interpersonal functioning tasks. All participants completed the Revised Mind in the Eyes Task (MET), the Cognitive and Emotional Perspective Taking Task (CEPTT), and the Index of Peer Relations (IPR). Type I BD patients reported greater peer difficulties on the IPR compared to HC, and also performed more poorly on the MET and the cognitive condition of the CEPTT, but did not differ significantly on the emotional condition. There were no significant group differences between type II BD patients and HC. More impaired ToM performance was associated with poorer interpersonal functioning. Type I BD patients show deficits in the ability to understand another's mental state, irrespective of emotional valence. Deficits in understanding others' mental states could be an important treatment target for type I pediatric patients with BD.