Differences in theory of mind between early and chronic stages in schizophrenia

Abstract

The evolution of social cognition throughout the course of schizophrenia is unclear not being possible to state whether it remains stable from early stages to chronicity, or it changes as the disease develops. For this purpose, 90 patients with schizophrenia and 139 healthy controls have been compared establishing 4 different groups paired by age and gender: first episode of psychosis patients (FEP), young healthy controls (YHC), chronic patients with schizophrenia (CS) and adult healthy controls (AHC). Performance in Theory of Mind (ToM) has been assessed using The Hinting Task and The Reading the Mind in the Eyes Test (RMET). In the Hinting Task, when comparing patients with their respective control group, differences found between CS patients and their corresponding controls (p < .001) are much bigger (almost twice) than differences between FEP patients and young controls (p = .001). In fact, young and adult healthy controls did not significantly differ in their scores, while the CS group showed significant worse performance than the FEP group. In the Reading the Mind in the Eyes test (RMET), patients globally performed worse than controls (p < .001). However, the Cohort × Diagnosis interaction was not significant (p = .27). In this task, there were no differences between CS and FEP scores. In conclusion, data suggest poor performance in all phases of the disease with a probable worsening related to chronicity especially in the aspects of social cognition measured by the Hinting Task.

Keywords: Chronic stages; Early stages; Schizophrenia; Theory of mind.