Executive dysfunction in schizophrenia and its association with mentalizing abilities.
Background: Patients with schizophrenia have been found impaired in important aspects of their basic and social cognition. Our aim in this study is to explore the relationship between executive function (EF) and theory of mind (ToM) deficiencies in patients that suffer the illness.
Methods: Twenty-two Spanish-speaking inpatients and 22 healthy controls matched in age, sex, education, language dominance, and premorbid IQ were assessed in EF and ToM abilities. The former were assessed using 10 tasks that covered 5 cognitive dimensions and the latter using 3 different tasks. Correlation analyses were used to explore the level of association between executive and mentalizing abilities. A series of discriminant function analyses were carried out to examine the relative contribution of each executive and mentalizing task to discriminate between patients and controls.
Results: Patients showed impairments in both, executive and ToM abilities. The correlation analyses showed a virtual absence of association between EF and ToM abilities within the group of patients, and an almost opposite pattern within the healthy group. ToM performance was more accurate than executive performance to discriminate patients from controls.
Conclusions: Although EFs and ToM deficits come into view together in schizophrenia, they appear to belong to different and relatively independent cognitive domains.