Factor structure of paranoid schizophrenia: A prospective study

Paranoid schizophrenics were scored and analyzed using PANSS and principal component method on admission (T1, 480 patients), after 4 weeks (T2, 223 patients), after 8 weeks (T3, 146 patients) and after 6 months of treatment (T4, 104 patients). Seven factor models accounted for 68-74% of the variances (including models of 104 patients present at all four stages). T1 and T2 models comprised 6-7 factors and were dominated by positive and excitement symptoms. The grandiosity factor could only be identified in T1. T3 and T4 models were reduced to 5 factors and incorporated a greater expression of depressive disorders and a relatively greater expression of negative and cognitive symptoms. Negative and cognitive dimensions were the most stable elements of all the models. The concept of the depressive factor appeared to be too restrictive to describe a whole variety of the affective dimension. Copyright (C) 2003 S. Karger AG, Basel.