Impact of cognitive dysfunction and symptoms on social outcome of outpatients with schizophrenia

Background

Poor social and occupational functioning is a defining feature of schizophrenia present even from the first-episode of the illness. The purpose of the current study was to investigate the relationship of cognitive dysfunction and symptoms with quality of life in a group of Greek outpatients with schizophrenia.

Material and Methods

Participants were 40 outpatients with schizophrenia (DSM-IV): 25 men and 15 women, all receiving antipsychotic medication at the time of the study. Their mean age was 36.3 years (SD = 9.6), their mean level of education was 10.9 years (SD = 3.3) and their mean duration of illness was 11.0 years (SD = 8.2). Social adjustment was assessed with the Greek version of Quality of Life Scale (QLS; interpersonal relations, instrumental role functioning, intrapsychic foundation, and common objects and activities subscales). Symptoms of schizophrenia were measured with the Greek version of the Positive and Negative Syndrome Scale (PANNS; positive, negative, and general psychopathology subscales), and extrapyramidal symptoms with the Extrapyramidal Symptom Rating Scale (ESRS; subjective complains, parkinsonism, dystonia, and tardive dyskinesia). Finally, a battery of neuropsychological tests was administered in order to assess the following cognitive domains: executive functions-abstraction, executive functions-inhibition, executive functions-fluency, verbal memory, visual memory, working memory, attention, visuospatial ability, and psychomotor speed/visual scanning.

Results

Scores on the interpersonal relations subscale were significantly (at p < 0.01) related with negative symptoms [r(40) = 0.66], parkinsonism [r(40) = -0.47], and executive functions-fluency [r(35) = 0.60]. The relationship of scores on the instrumental role functioning subscale with other measures did not meet our conservative criterion of significance. Performance on the intrapsychic foundation subscale was significantly correlated with negative symptoms [r(40) = -0.61], and executive functions-fluency [r(35) = 0.51]. Finally, scores on the common objects and activities subscale were significantly related with negative symptoms [r(40) = -0.60], parkinsonism [r(40) = -0.57], executive functions-fluency [r(35) = 0.48], visual memory [r(38) = 0.47], and psychomotor speed/visual scanning [r(38) = 0.47].

Discussion

Our findings suggest that severity of negative symptoms, parkinsonism, and cognitive dysfunction, especially performance on measures of executive functions, are important determinants of functional outcome in schizophrenia.