Negative Symptoms Independently Predict Theory of Mind Impairment in Clinically Stable Schizophrenia

theory of mind (ToM) impairment is a well-established feature of schizophrenia; however, the relative contribution of negative symptoms and disorganization remains unclear, particularly in clinically stable outpatients. Moreover, few studies have modeled symptom domains simultaneously while accounting for illness chronicity and antipsychotic exposure.

in this cross-sectional case-control study, 52 clinically stable outpatients with schizophrenia and 52 healthy controls completed the Reading the Mind in the Eyes Test (RMET). Symptom dimensions were derived from the Positive and Negative Syndrome Scale (PANSS) using a five-factor framework. Hierarchical regression analyses examined independent predictors of RMET performance within the schizophrenia group. Sensitivity analyses included illness duration, olanzapine-equivalent dose, and alternative disorganization operationalizations. Receiver operating characteristic (ROC) analysis evaluated discriminative capacity.

patients demonstrated significantly lower RMET scores than controls (d = -1.42, p < .001). Within the schizophrenia group, negative symptoms (β = -.33, p = .015) independently predicted RMET performance after controlling for demographic variables and disorganization. This association remained robust after adjusting for illness duration and medication dose. Disorganization showed modest bivariate associations but did not retain independent predictive value in multivariable models. RMET demonstrated good discriminative accuracy (AUC = 0.84), with high specificity at the optimal cut-off.

ToM impairment in clinically stable schizophrenia is substantial and appears more strongly linked to negative symptom severity than to disorganization. These findings support routine assessment of social cognition in patients with prominent negative symptoms and highlight the dimensional interplay between motivational deficits and social-cognitive dysfunction.