Do the siblings of schizophrenia patients demonstrate affect perception deficits?

Affect perception deficits have been extensively documented in schizophrenia and are associated with the social dysfunction that is characteristic of this disorder. The two previous studies examined facial affect perception in genetically at-risk samples and yielded mixed results. The current study was designed to provide a rigorous test of affect perception abilities among schizophrenia patients (n=58), their biological siblings without psychosis (n=51), and nonpsychiatric controls (n=49). Participants completed three measures of affect perception, including facial, vocal, and combined modality. Schizophrenia patients performed significantly worse than controls on two of the three affect perception tests as well as a composite index based on all three tests. The performance of the sibling group fell between the patient and control groups on each of the affect perception tests. However, group differences achieved statistical significance only for the composite index with the siblings performing significantly worse than controls and significantly better than the schizophrenia group. These findings demonstrate that subtle deficits in affect perception are detectable in the unaffected siblings of schizophrenia patients when multiple measures of different types of affect perception abilities are used in combination.