Objective: Impairments in social cognition are observed in bipolar disorder and schizophrenia; consequent effects on interpersonal and social functioning may depend on the extent of social cognitive disturbances. We hypothesized (a) that social cognitive difficulties would be present in both bipolar disorder and schizophrenia, and (b) that specific deficits in social cognition would differentially predict levels of empathy and social functioning.

Methods: Nineteen participants with bipolar disorder, 24 participants with schizophrenia and 18 healthy controls completed The Awareness of Social Inference Test (TASIT) to examine emotion perception and mental state inference from short vignettes of sincere, deceitful and sarcastic interactions. The Interpersonal Reactivity Index (IRI) assessed empathy, and the Longitudinal Interval Follow-up Evaluation - Range of Impaired Functioning Tool (LIFE-RIFT) provided a measure of social functioning.

Results: Participants with bipolar disorder performed significantly poorer than controls only on complex social cognitive inferences on the TASIT, whereas schizophrenia participants performed significantly worse than controls on all social cognition tasks. In bipolar disorder: impaired emotion perception predicted lower self-reported empathy, and accurate detection of the communication of sarcastic and deceitful exchanges predicted less engagement in recreational activities. In schizophrenia, impaired theory of mind predicted lower recreational functioning, and impaired detection of sarcastic exchanges was associated with higher self-reported empathic personal distress.

Conclusions: Social cognition was more severely impaired in schizophrenia compared to bipolar disorder. Specific social cognitive skills differentially contributed to interpersonal and social functioning in these conditions, with implications for the remediation of social cognitive deficits in bipolar disorder and schizophrenia.