Picture sequencing task performance indicates theory of mind deficit in bipolar disorder

Background This paper reports the performance of DSM-IV-TR diagnosed bipolar disorder (BD) patients on a well-recognised measure of theory of mind (ToM) that commonly elicits group-related differences in schizophrenia research. Methods Forty-nine BD patients and 49 age and gender matched controls completed Langdon and Coltheart (1999) Picture Sequencing Task. Results Relative to controls, patients with BD performed significantly worse on the ToM relevant false-belief stories of the picture sequencing task, but not on the control stories requiring social script knowledge, executive control or an understanding of causal connexions. There were no differences in the ToM performance of symptomatic versus euthymic patients or those categorised as having BD I or BD II. Limitations As sub group sizes were small, data suggesting a trait-like deficit in ToM should be interpreted with caution. Conclusions The results support previous evidence of ToM impairment in BD and indicate a potential endophenotypic overlap in the phenomenology of both schizophrenia and BD. ? 2013 Elsevier B.V.