Cognitive impairment contributes to the development and the outcome of schizophrenia (SZ), but there is considerable less data about cognitive functioning in schizoaffective (SZAFF) and bipolar (BD) disorder with psychotic symptoms.

Seven basic cognitive functions were examined in patients with SZ, BD and SZAFF to assess the cognitive deficits and their patterns.

The aim of the study was to obtain data on the structure of cognitive functions in psychosis spectrum in an effort to employ these findings to improve the therapeutic interventions.

Twenty SZ, 21 BD and 20 SZAFF outpatients were involved in the study. the following cognitive functions were examined: phonological and visual working memory (WM), perseveration, planning and learning during task solving. the severity of the clinical symptoms was also assessed.

BD patients performed better than the SZ (p = 0.025) and the SZAFF (p = 0.025) group on one phonological WM task. Patients with SZ had significantly lower level of conceptual choices in the Wisconsin Card Sorting Test (WCST) compared to BD (p = 0.007). Correlations between the different measures of the WCST and the clinical state of the patients might indicate that the severity of the residual symptoms results in weaker performance on working memory tasks.

According to our data SZ patients show poorer performance on the cognitive tasks considered. As these cognitive processes play an important role in everyday life and they might contribute to the functional outcome of psychotic disorders, these cognitive areas should be part of the rehabilitation programmes of SZ.