Original article
Disturbances of the theory of mind and empathy in schizophrenia and bipolar affective illness

Background: Research on social cognition conducted in recent years suggests abnormalities of the theory of mind (ToM) and empathy among patients with schizophrenia and bipolar disorder (BD). The aim of this study is to compare the deficits of social cognition in both disorders.

Material and methods: The study involved 20 patients diagnosed with schizophrenia and 20 diagnosed with BD, among them 8 after a manic episode and 12 after a depressive episode. The control group consisted of 40 healthy subjects. The Eyes Test (Reading the Mind in the Eyes Test – RME), developed by Simon Baron-Cohen was used to study ToM. Empathy was assessed through the Multifaceted Empathy Test (MET) developed by Izabel Dziobek. To assess cognitive function, CANTAB battery tests were used, which examine motor function (Motor Screening Task – MOT), memory (Pattern Recognition Memory – PRM) and cognitive planning (Stockings of Cambridge – SOC).

Results: In both groups ToM deficits were found, significantly greater in patients with schizophrenia compared with BD. Both groups had deficits on cognitive aspects of empathy, with schizophrenia patients recognizing negative emotions significantly worse than patients with BD. The greatest pathological hyperactivity of the affective aspect of empathy was displayed by patients with BD after a manic episode. Slightly lower, although significantly greater than in the control group in this respect, were schizophrenic patients. In both diagnostic groups worse results in psychomotor speed, memory and spatial planning were observed. No relationship was found between the results of cognitive functions and disturbances of ToM and both cognitive and affective aspects of empathy.

Conclusions: Disturbances of ToM as well as both cognitive and affective aspects of empathy were found in patients with schizophrenia and bipolar disorder. In ToM and negative cognitive aspects of empathy they are larger in patients with schizophrenia. Disturbances of the affective aspect of empathy are biggest in BD patients after a manic episode. The study showed the independence of ToM and empathy.