Deficits in domains of social cognition in schizophrenia: a meta-analysis of the empirical evidence.

OBJECTIVE: Social cognition is strongly associated with functional outcome in schizophrenia, making it an important target for treatment. Our goal was to examine the average magnitude of differences between schizophrenia patients (SCs) and normal comparison (NCs) patients across multiple domains of social cognition recognized by the recent NIMH consensus statement: theory of mind (ToM), social perception, social knowledge, attributional bias, emotion perception, and emotion processing.
METHOD: We conducted a meta-analysis of peer-reviewed studies of social cognition in schizophrenia, published between 1980 and November, 2011.
RESULTS: 112 studies reporting results from 3908 SCs and 3570 NCs met our inclusion criteria. SCs performed worse than NCs across all domains, with large effects for social perception (g = 1.04), ToM (g = 0.96), emotion perception (g = 0.89), and emotion processing (g = 0.88). Regression analyses showed that statistically significant heterogeneity in effects within domains was not explained by age, education, or gender. Greater deficits in social and emotion perception were associated with inpatient status, and greater deficits in emotion processing were associated with longer illness duration.
CONCLUSIONS: Despite the limitations of existing studies, including lack of standardization or psychometric validation of measures, the evidence for deficits across multiple social cognitive domains in schizophrenia is clear. Future research should examine the role of neurobiological and psychosocial factors in models linking various aspects of deficit in schizophrenia, including social cognition, in order to identify targets for intervention.