Social cognition in early schizophrenia: exploratory factor analysis and subcortical biomarkers

Abstract

BACKGROUND: One of the central determinants of functional outcome in schizophrenia is social cognition (SC). With the wide array of SC domains, factor-analysis provides a powerful tool to identify commonalities amongst their underlying dysfunctions and its neural underpinnings. METHODS: The present study performed exploratory factor analysis (EFA) on 93 patients with early course schizophrenia using eight validated SC subtests. Factors derived from this analysis were then used to investigate their relationships with neurocognitive performance, clinical symptoms, and functional outcome. Moreover, subsequent shape analysis of the amygdala and hippocampus was performed using the MAGeT Brain pipeline to investigate their relationship to the composite scores of SC factors. RESULTS: EFA revealed a 3-factor solution, representing the domains of emotion management, emotion recognition, and theory of mind-social contextual appraisal, together accounting for 63.58% of the variance. Interestingly, only the theory of mind-social context appraisal factor correlated with measures of functional outcome. Addition analysis revealed that higher score on the theory of mind factor is significantly related with higher functional outcome measures and verbal learning performance, as well as with lower negative symptoms. Both emotion management and emotion perception factors indicated significant positive correlations with attention-vigilance while only emotion perception significantly correlated with visual learning and memory. Outward convexity of the right amygdala was identified to be positively correlated with the theory of mind-social context appraisal factor (p<0.05, FDR corrected), while the left and right hippocampus, specifically greater surface area of the dorsal-medial and ventral-lateral aspect of the hippocampus respectively, were positively correlated with higher composite score on theory of mind factor (p<0.05, FDR corrected). CONCLUSION: Our EFA indicates overlap amongst SC subtests which represent three different SC subdomains. Furthermore, shape analysis reveals that displacement and surface area of the amygdala and hippocampus respectively play a role in theory of mind. In the future, the SC factors that we identified, along with their neural correlates, could provide essential diagnostic tools to assess SC functioning in early schizophrenia patients, as well as identify strategies for potential improvement following cognitive remediation therapy.