Empathic disequilibrium in schizophrenia: An individual participant data meta-analysis.

Schizophrenia involves substantial social difficulties, yet their nature remains unclear. Although empathy has been considered a promising social cognition construct, inconsistent findings have undermined its usefulness as a stable index for schizophrenia. This may be because previous studies overlooked the interdependency between the emotional and cognitive components of empathy. In this study, we investigated whether empathic disequilibrium, the intrapersonal imbalance between emotional and cognitive empathy, could be a meaningful schizophrenia marker. We conducted an individual-participant data meta-analysis, systematically searching the literature for studies involving participants with schizophrenia who completed the Interpersonal Reactivity Index, a validated empathy measure. Using emotional and cognitive empathy to capture empathic disequilibrium and the joint effect of cognitive and emotional empathy, we employed polynomial regression with response surface analysis to predict schizophrenia diagnosis and symptoms. Our analysis comprising ten studies (N = 1,080), revealed a non-linear association with the joint effect of cognitive and emotional empathy, as well as an association with empathic disequilibrium, suggesting emotional empathy overabundance, strongly and consistently predicted schizophrenia diagnosis. Additionally, empathic disequilibrium towards cognitive empathy overabundance was related to greater positive symptoms. The results suggest that empathic disequilibrium provides a stable behavioral marker related to schizophrenia, surpassing the utility of empathy alone. The findings deepen our understanding of schizophrenia phenomenology and can advance clinical and research practices.