Theory of mind deficit found in bipolar disorder
medwireNews: People with bipolar disorder show theory of mind impairment, based on impaired performance on the Picture Sequencing Task, Australian researchers have found.
The Task is a well recognized measure of theory of mind that commonly elicits deficits in people with schizophrenia, explain the study authors, who say their results indicate that “impairment on the task may represent potential overlap in the phenomenology and possibly genetic aetiology of schizophrenia and [bipolar disorder].”
Tamsyn Van Rheenen and Susan Rossell, from Monash Alfred Psychiatry Research Centre in Melbourne, Victoria, Australia, studied 49 patients with bipolar disorder and 49 psychiatrically healthy controls matched for age and gender. All participants completed the Task, which assesses the ability to make inferences about other people’s emotional and mental states.
Results, reported in the Journal of Affective Disorders, show that people with bipolar disorder performed significantly worse than healthy individuals on the “false belief” story part of the Task, with an average 11.9% decrement in accuracy. These stories require the inference of false beliefs and were the main focus of the study.
Patients and controls performed similarly on the mechanical, social script, and capture stories. Further analysis found that patients’ performance on the Task did not differ according to diagnostic subtype, current mood state, or use of psychotropic medications.
Noting that their results should be interpreted cautiously in view of the small sample size, Van Rheenen and Rossell say the data nevertheless “appear to suggest that patient impairment for false belief inferences may represent a stable, trait-like feature in [bipolar disorder].”
The results also “mirror some prior evidence of selective false-belief impairments on the picture sequencing task in schizophrenia patients” and support previous findings which indicate “trait-like [theory of mind] deficits in [bipolar disorder] itself.”
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Joanna Lyford, Senior medwireNews Reporter