The negative syndrome of schizophrenia: three -underlying components are better than two.

Abstract:

AIMS: To analyse the underlying structure of the negative syndrome of schizophrenia as it is represented in the Brief Negative Symptom Scale. METHODS: Cross-sectional, multicentre study, employing data from 190 evaluations. STATISTICS: Exploratory factor analysis using the principal component analysis method. RESULTS: The three-component solution explained 77.4% of the total variance. Pearson correlation coefficients between components were: 1-2=-0.494, 1-3=-0.117, and 2-3=0.179. CONCLUSION: Our solution favours a three-component structure of the negative syndrome, consisting of: external world (anhedonia and asociality), inner world (avolition and blunted affect), and alogia, with the latter only marginally related to the two former components.