Neurokognitive Veränderungen und Negativsymptomatik bei schizophrenen Erkrankungen

Abstract

It is widely recognized that schizophrenic disorders are often associated with impairments of cognitive performance. More recently, disorders of higher cognitive control processes ("executive control functions") have captured the attention of researchers as they can considerably impair patients' abilities to live an independent life. Apart from that, considering the heterogeneity of schizophrenia, there have been attempts to relate psychopathological syndromes to changes in distinct cognitive domains. The present review selectively focuses on evidence associating negative symptoms in schizophrenia with deficient performance in specific executive domains. Neurobiological evidence points to biochemical, structural and functional abnormalities in the frontal cortex and associated fronto-subcortical circuits as a common basis of both schizophrenic negative symptoms and disorders of executive control. In a multitude of neuropsychological studies, an association between negative symptoms and problems in the domains of response inhibition, multitasking, cognitive flexibility, contextual updating, problem solving and verbal fluency has been reported. In some cases, however, the disorganization syndrome but not the negative syndrome has been linked with impaired behaviour in these domains. The inconsistencies might be partly due to the unsatisfactory differentiation between the two symptom complexes. Future research should furthermore consider a more precise differentiation between primary and secondary negative symptoms. Finally, the assessment of executive control functions should be both specific and ecologically valid.

The relationship between executive functions and fluid intelligence in schizophrenia

“…In parallel to this factor analytic work, neuropsychological studies of schizophrenia show deficits in a range of executive tests, including the WCST, multitasking and tests of social cognition (e.g., Liddle and Morris, 1991; Frith et al, 1992; Thoma and Daum, 2005; Thoma et al, 2007; Kim et al, 2009; Egan et al, 2011; Banno et al, 2012; Cochrane et al, 2012; Erol et al, 2012; Baez et al, 2013; Fond et al, 2013; Sánchez-Torres et al, 2013). Again there is evidence for some link to fluid intelligence.…”

Decline in working memory in stable schizophrenia may be related to attentional impairment: mediating effects of negative symptoms

“…These ndings suggest that targeting negative symptoms may lead to improvements in attention and working memory, thereby bene ting overall cognition. Neurobiological evidence further supports the connection between negative symptoms and executive/attentional dysfunction in schizophrenia, involving biochemical, structural, and functional abnormalities in the frontal cortex and related subcortical circuits [25][26][27]. Additionally, signi cant negative correlations were observed between intrinsic hippocampal activity in schizophrenia, a broad range of cognitive measures, and its association with negative symptoms [28] .…”

Decline in Working Memory in Stable Schizophrenia May Be Related to Attentional Impairment: Mediating Effects of Negative Symptoms, a Cross-Sectional Study

“…Neurobiological evidence further supports the connection between NS and executive/attentional dysfunction in SCZ, involving biochemical, structural, and functional abnormalities in the frontal cortex and related subcortical circuits. 34–36 Additionally, significant negative correlations were observed between intrinsic hippocampal activity in SCZ, a broad range of cognitive measures, and its association with NS. 37 NS and cognitions in schizophrenia have always been a challenge to treat.…”