BACKGROUND: Recent research has shown a significant impact of social cognitive domains on real world functioning and prognosis in schizophrenia. However, the correlations between specific aspects of social cognition, neurocognition, IQ and clinical symptoms remain unclear in first-episode schizophrenia. Researchers have speculated about social cognitive subgroups since patients with schizophrenia appear to be a very heterogeneous group. METHODS: Patients with a recent diagnosis of first-episode schizophrenia were tested regarding theory of mind, social perception, neurocognition, IQ, and clinical symptoms. RESULTS: Data from 36 first-episode schizophrenia patients and 36 one to one matched healthy controls were analysed. Principal component analysis in the patient group was used to examine the variance contributed by different aspects of social cognition, neurocognition, and clinical symptoms. CONCLUSIONS: Complex aspects of social cognition explained 24% of the variance in the patient group. The other principal components consisted mainly of aspects of simple perception of theory of mind. Neurocognition and clinical symptoms only explained a minor proportion of the variance in the patient group. The results imply that social cognitive deficits in first-episode schizophrenia come in two distinct versions where one is a complex, cognitive demanding form linked with IQ. The other version is related to simpler forms of social cognition and independent of IQ. These two forms are comparable to the implicit and explicit mentalising discussed in the developmental literature. The two forms of social cognitive deficits are likely to require quite different social cognitive interventions.
Schizophrenia Research, 2014, Vol 153, Issue 1-3, p. 9-17