Theory of Mind in first-episode schizophrenia patients: correlations with cognition and personality traits

There is substantial evidence for Theory of Mind (ToM) deficits in patients with schizophrenia. Many psychotic symptoms may best be understood in light of an impaired capacity to infer one's own and other persons' mental states and to relate those to executing behavior. The aim of our study was to investigate ToM abilities in first-episode schizophrenia patients and to analyze them in relation to neuropsychological and psychopathological functioning.

A modified Moving Shapes paradigm was used to assess ToM abilities in 23 first-episode patients with schizophrenia and 23 matched healthy controls. Participants had to describe animated triangles which moved (1) randomly, (2) goal-directed, or (3) in complex, socially interactive ways (ToM video sequences). Neuropsychological functioning, psychopathology, autistic and alexithymic features as well as empathetic abilities were correlated with ToM performance.

Compared to healthy controls, first-episode schizophrenia patients gave more incorrect descriptions and used less ToM-related vocabulary when responding to socially complex ToM video sequences. No group differences were revealed for videos with random movements. ToM abilities correlated significantly with positive symptoms, reasoning, verbal memory performance and verbal IQ, but not with empathetic abilities or autistic and alexithymic features. When controlling for reasoning, verbal memory performance and verbal IQ, the correctness of video descriptions was still significantly worse in schizophrenia patients.

The results of our study in first-episode schizophrenia patients underline recent findings on ToM deficits in the early course of schizophrenia. Only a moderate influence of neurocognitive deficits on ToM performance was observed. Impairment in ToM abilities seems to be predominantly independent of clinical state, alexithymia and empathy.