Neurocognitive impairment in deficit and non-deficit schizophrenia: a meta-analysis

Abstract

BackgroundMost studies suggested that patients with deficit schizophrenia have more severe impairment compared with patients with non-deficit schizophrenia. However, it is not clear whether deficit and non-deficit schizophrenia are associated with differential neurocognitive profiles.MethodsThe aim of this meta-analytic review was to compare cognitive performances of deficit and non-deficit patients with each other and with healthy controls. In the current meta-analysis, differences in cognitive abilities between 897 deficit and 1636 non-deficit patients with schizophrenia were examined. Cognitive performances of 899 healthy controls were also compared with 350 patients with deficit and 592 non-deficit schizophrenia.ResultsBoth deficit (d= 1.04–1.53) and non-deficit (d= 0.68–1.19) schizophrenia were associated with significant deficits in all cognitive domains. Deficit patients underperformed non-deficit patients in all cognitive domains (d= 0.24–0.84) and individual tasks (d= 0.39–0.93). The relationship between deficit syndrome and impairment in olfaction, social cognition, verbal fluency, and speed-based cognitive tasks were relatively stronger.ConclusionsOur findings suggest that there is consistent evidence for a significant relationship between deficit syndrome and more severe cognitive impairment in schizophrenia.