Multidimensional scaling analysis of paranoid symptoms in the context of depressive and psychotic disorders

The present study examined a continuum of paranoid symptoms in the context of depressive and psychotic disorders from a multidimensional perspective on psychopathology. Based on the self-ratings of 404 community residents, 96 depressed patients, and 65 psychotic patients, similarities or dissimilarities among multiple measures of paranoia (i.e. mild, moderate, and severe types), along with 16 other psychiatric symptom scales taken from the Psychiatric Epidemiology Research Interview (PERI; Dohrenwend, Shrout, Egri & Mendelsohn, 1980, Dohrenwend, Levav & Shrout, 1986b, were analysed using multidimensional scaling supplemented by cluster analysis. Four hypotheses were tested. Only one hypothesis was fully supported and two were partially supported. No distinct dimension for the continuum of paranoia emerged, but a global dimension of severity of psychopathology was pervasive and stable across diagnostic subgroups. The latter finding replicated and extended previous multidimensional studies of psychopathology.