Validity of the PANSS cognitive factor as a measurement of cognitive performance in schizophrenia

IntroductionThe Positive and Negative Syndrome Scale (PANSS) is a widely used instrument for measuring symptomatology in patients with schizophrenia. Numerous studies have analyzed the factorial structure of this scale and have suggested a five factor model, namely: negative, positive, excited, anxiety/depression, and disorganized (or cognitive). The latter factor has been related to neuropsychological tests, with a view to analyzing its utility as a measure of cognitive functioning in schizophrenia, but data are inconclusive. The aim of the present study was to analyze the factorial structure of the PANSS and to assess the relationships between factors and neurocognitive tests.Material and methodsThe sample comprised 235 outpatients diagnosed with schizophrenia. To investigate the factorial structure of the PANSS, a principal component factor analysis was performed. Cognitive functioning was measured with a shortened version of the Barcelona Test.ResultsUnlike previous studies, our study obtained a six-factor model, with disorganized and cognitive symptoms separated in two different factors. The cognitive factor obtained in this study was related to all subtests of the Barcelona Test. The disorganized factor, however, was only related to two of these subtests.ConclusionsOur results support the use of a six-factor model and suggest that the cognitive factor could be a valid measure of cognitive deficits in schizophrenia, although the use of a standard neuropsychological battery is advisable.

ResumenIntroducciónLa Escala de los Síndromes Positivo y Negativo (PANSS) es uno de los instrumentos más utilizados para valorar la sintomatología de los pacientes con esquizofrenia. Numerosos estudios han analizado la estructura factorial de esta escala, y han propuesto la existencia de cinco factores: negativo, positivo, excitación, ansiedad/depresión y desorganización (o cognitivo). Este último factor se ha relacionado con pruebas neuropsicológicas con la finalidad de analizar su utilidad como medida del rendimiento cognitivo en esquizofrenia, aunque no se han obtenido resultados concluyentes. El objetivo del presente estudio es analizar la estructura de la PANSS y relacionar los factores obtenidos con pruebas cognitivas.Material y métodosLa muestra del estudio está compuesta por 235 pacientes, diagnosticados de esquizofrenia, que viven en la comunidad. La estructura de la PANSS se valoró mediante un análisis factorial de componentes principales. Para evaluar el rendimient