Social cognition in bipolar disorder versus schizophrenia: comparability in mental state decoding deficits.

OBJECTIVES: Neuropsychological studies comparing patients with bipolar disorder (BD) to patients with schizophrenia (SZ) suggest milder cognitive deficits in BD patients and across a smaller range of functions. The present study investigated whether this pattern is also true for social cognition - a range of socially relevant abilities, including emotion perception and recognition, theory of mind, and social attributions - by comparing performance on measures of social cognition in patients with BD, SZ, and healthy participants.
METHODS: One hundred and two patients with BD, 208 patients with SZ, and 132 healthy participants were assessed using a battery of tasks measuring basic neuropsychological and social cognition.
RESULTS: We observed significant differences between patients with BD and healthy participants in a test of mental state decoding ('eyes task') that was at a level comparable to deficits seen in patients with SZ. By comparison, BD patients showed more subtle deficits in mental state reasoning ('hinting task') than those shown by patients with SZ.
CONCLUSIONS: Mental state decoding difficulties are significant in BD. An important direction for further research will be to establish to what extent these deficits affect social and occupational functioning as a potential target for therapeutic intervention.