Objective: i) To investigate the subtle ToM (theory of mind) deficits in euthymic patients with bipolar disorder. ii) To investigate the impact of non-ToM cognitive deficits on ToM abilities.
Method: Forty-three euthymic patients with bipolar disorder and 30 healthy control subjects were involved in this study. ToM was assessed by the Eyes test and the Hinting task. Both groups were also evaluated with a comprehensive neuropsychological battery including tasks for basic emotion and face recognition.
Results: The patient group was impaired on both of the ToM tasks. The patient group also showed impairment in many cognitive tasks including tasks related to sustained attention.
Conclusion: Even euthymic patients with bipolar disorder may be impaired in advanced ToM tasks. Executive dysfunction and some other cognitives deficits such as basic emotion recognition may be at least partly responsible for this result.