Neuropsychological functioning in schizoaffective disorder, depressed type

Abstract

Neuropsychological functioning in schizoaffective disorder, depressed type, was tested by two parallel studies. In Study 1, the Luria-Nebraska Neuropsychological Battery (LNNB) was administered to samples of patients meeting Research Diagnostic Criteria (RDC) for schizodepressive disorder, major depressive disorder or schizophrenia, and to a normal control group. In Study 2, the same test battery was used in patients with a former RDC diagnosis of schizodepressive or major depressive disorder, examined from 2 to 4 years after the index episode, during a phase of remission. Study 1 showed that the performance of schizodepressives on LNNB is, on average, intermediate between those of depressives and schizophrenics, which finding is compatible with the view that RDC schizoaffective depression encompasses a heterogeneous group of syndromes, some of which are related to major depression and some to schizophrenia. Study 2 showed that the mean scores on the LNNB scales Memory and Intellectual processes are significantly higher in patients with a former diagnosis of schizodepressive disorder, which supports the idea that the outcome of these patients is worse, on average, than that of "pure" depressives.

Examining cognition across the bipolar/schizophrenia diagnostic spectrum

“…Two smaller studies found no differences between participants with the depressive sub type and participants with schizophrenia, but neither con sidered the bipolar subtype. 14,19 This suggests that con sidering both subtypes of schizoaffective disorder as a single group may obscure findings. To our knowledge, no published studies have compared the subtypes of schizoaffective disorder individually to schizophrenia and bipolar disorder.…”

“…For this analysis, we combined the schizophrenia and schizoaffec tive depressive groups into a single group based on pre existing data suggesting that performance between these groups is equivalent. 10,14,19 Third, we examined whether cog nitive performance was associated with symptom domains across diagnostic groups.…”

“…We combined schizophrenia and schizoaffective depressive, given pre existing data indicating that their degree of impairment is comparable. 10,14,19 Diagnosis was coded on an ordinal scale: 0 = schizoaffective depressive and schizophrenia, 1 = schizoaffective bipolar, 2 = bipolar disorder.…”

Examining cognition across the bipolar/schizophrenia diagnostic spectrum

“…The study by Hill et al 10 showed greater overall impairment in participants with the depressive subtype of schizoaffective disorder than the bipolar subtype, although the differences were not significant. Two smaller studies found no differences between participants with the depressive subtype and participants with schizophrenia but did not consider the bipolar subtype 14,19 . This suggests amalgamation of both subtype of schizoaffective disorder as a single group may obscure findings.…”

“…Secondly, we examined whether cognition can be considered a continuous measure across disorders. For this analysis, the schizophrenia and schizoaffective depressive groups were combined into a single group based on preexisting data suggesting that performance between these groups is equivalent 10,14,19 . Thirdly, we examined whether cognitive performance is associated with symptoms domains across diagnostic groups.…”