Objective: This paper reports on a study designed to (i) assess levels of executive functions among patients suffering from schizophrenia; (ii) investigate associations between measures of executive functions and psychosocial adjustment; and (iii) examine the influence of psychopathology on the relationship between executive functions and psychosocial adjustment. Clear knowledge of executive functions and of their impact on social adjustment in patients with schizophrenia may play a decisive role in preparing and structuring appropriate outpatient care.
Method: An extensive battery constituted of several tests developed for the assessment of executive functions was used in 38 inpatients with a DSM-IV diagnosis of schizophrenia. Psychosocial adjustment was assessed with a set of commonly used scales.
Results: Performance on measures of executive functions was heterogeneous among the patient population, with a subgroup performing within normal scores. A similar pattern was found on measures of psychosocial adjustment. Most of the executive measures were not dependent on demographic or clinical variables. A factorial analysis on measures of psychosocial adjustment yielded a one-factor model which showed inconsistent, and at most, weak to moderate correlations with executive functions. Regression analysis revealed that symptom levels accounted for two-thirds of the variance of psychosocial adjustment, and together with measures of executive functions for 91% of the variance. General and negative symptoms showed strong correlations with psychosocial adjustment.
Conclusions: Our study supports the view that executive function is a heterogeneous construct with several subdimensions. Additionally, it suggests that symptom level has an important role as "rate limiting factor" on psychosocial adjustment and is partially mediated by executive dysfunction. Our results call for careful and detailed assessment in this patient population in order to establish appropriate treatment programmes such as cognitive remediation.