Clinical practice usually considers schizophrenia and bipolar disorder as two distinct nosological entities. Nevertheless, research over the past decades has shown similar impaired cognitive profiles in patients with schizophrenia and bipolar disorder. The objective of the present study was to verify whether the diagnostic distinction between these disorders effectively accounts for clinical, cognitive and functional profiles.
Materials and Methods
42 patients (mean age 44.3; 36% female), with diagnosis of schizophrenia (n = 23) or bipolar disorder (n = 19) in charge of an outpatient psychiatric public service were recruited. Cognitive abilities were measured with the MCCB. Clinical (BPRS, CGI) and functional (VGF, QL-index) scales were also administered. Linear regressions were conducted investigating whether the diagnosis could predict neurocognitive outcomes and examining the effects of neurocognitive performances on functional outcome.
Both groups showed comparable performances in all cognitive domains and diagnosis was not a significant predictor of any cognitive variable. Moreover, lower scores in working memory and speed of processing predicted worse functioning.
The present findings support the perspective of a continuum between schizophrenia and bipolar disorder and further underline the importance of neurocognitive examination in psychiatric diseases, in light of its fundamental role in predicting daily functioning.