TY - JOUR
T1 - Hierarchical structure of the cognitive processes in schizophrenia
T2 - The fundamental role of processing speed
AU - Ojeda, N.
AU - Peña, J.
AU - Schretlen, D. J.
AU - Sánchez, P.
AU - Aretouli, E.
AU - Elizagárate, E.
AU - Ezcurra, J.
AU - Gutiérrez, M.
N1 - Funding Information:
This research was partially supported by the Spanish Ministry of Health , Instituto de Salud Carlos III , CIBERSAM , Instituto de Salud Carlos III, FIS grant number PIO70245 and EITB-Maratoia ( BIO09/EM/023 ).
PY - 2012/3
Y1 - 2012/3
N2 - Objective: Decreased processing speed (PS) is a key feature of schizophrenia with respect to cognition, functional outcome and clinical symptoms. Our objective was to test whether PS slowing mediates other neuropsychological deficits among patients with chronic schizophrenia. Method: One hundred patients with schizophrenia and 53 healthy adults completed a series of neuropsychological measures that assess six cognitive domains. In addition to PS these included attention, verbal memory, visual memory, working memory, and executive functioning. Confirmatory factor analysis (CFA) was used to evaluate the fit of the 6-factor model. The cognitive performances of both groups were compared before and after controlling for the effect of PS, but also after controlling for the effect of each cognitive factor at a time. Finally, the PS-related variance was removed and the effect of the other cognitive factors was tested again. Results: CFA supported the hypothesized 6-factor cognitive structure. As expected, the patients and controls differed on all cognitive measures. However, after controlling for the effects of PS, group differences on the other five cognitive factors decreased substantially. Controlling for other factors produced smaller attenuation of group differences, and these effects were also partially accounted for by decreased PS. Conclusions: PS deficits account for most of the differences in cognition between patients with schizophrenia and healthy controls. PS slowing appears to be a core feature of schizophrenia, one that underlies impairments of working memory, executive functioning, and other abilities.
AB - Objective: Decreased processing speed (PS) is a key feature of schizophrenia with respect to cognition, functional outcome and clinical symptoms. Our objective was to test whether PS slowing mediates other neuropsychological deficits among patients with chronic schizophrenia. Method: One hundred patients with schizophrenia and 53 healthy adults completed a series of neuropsychological measures that assess six cognitive domains. In addition to PS these included attention, verbal memory, visual memory, working memory, and executive functioning. Confirmatory factor analysis (CFA) was used to evaluate the fit of the 6-factor model. The cognitive performances of both groups were compared before and after controlling for the effect of PS, but also after controlling for the effect of each cognitive factor at a time. Finally, the PS-related variance was removed and the effect of the other cognitive factors was tested again. Results: CFA supported the hypothesized 6-factor cognitive structure. As expected, the patients and controls differed on all cognitive measures. However, after controlling for the effects of PS, group differences on the other five cognitive factors decreased substantially. Controlling for other factors produced smaller attenuation of group differences, and these effects were also partially accounted for by decreased PS. Conclusions: PS deficits account for most of the differences in cognition between patients with schizophrenia and healthy controls. PS slowing appears to be a core feature of schizophrenia, one that underlies impairments of working memory, executive functioning, and other abilities.
KW - Chronic schizophrenia
KW - Neurocognition
KW - Processing speed
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U2 - 10.1016/j.schres.2011.12.004
DO - 10.1016/j.schres.2011.12.004
M3 - Article
C2 - 22226902
AN - SCOPUS:84857235422
SN - 0920-9964
VL - 135
SP - 72
EP - 78
JO - Schizophrenia Research
JF - Schizophrenia Research
IS - 1-3
ER -