Impairment of social cognition in comparative studies of patients with schizophrenia and their healthy siblings

Social cognition impairment is a kind of neurocognitive disturbance observed during clinical course of schizophrenia. Deficits in this field observed in first - degree unaffected relatives have been suggested as a potential endophenotype. The main purpose of this study was to review the range of published articles, mainly from the last decade, regarding social cognition impairment in patients with schizophrenia and their healthy siblings. The analysis used articles from the PubMed, Medline and Polish Medical Bibliography databases, searched using the following keywords: schizophrenia, healthy siblings, social cognition, theory of mind, facial emotion recognition. Works published in the time frame from 2010 to 2021 were included; in justified cases, earlier works were also used. Results of the review indicate a substantial agreement on how to classify relatives' deficits in social cognition. Most analyzed studies indicate their level of neurocognitive disturbance in between schizophrenic siblings and controls. Schizophrenic patients present impairment of social cognition, comparable deficits have been observed to a lesser degree in their healthy siblings. Moreover, results of majority of studies reveal correlations of social cognition dis-turbances with cognitive dysfunctions and subclinical psychopathology in healthy siblings. However, further research on more numerous groups is needed to draw reliable conclusions on this topic.