Use of factor analysis to detect potential phenotypes in obsessive-compulsive disorder

This study aimed to identify symptom dimensions in obsessive-compulsive disorder (OCD) in order to reveal distinct clinical phenotypes. Factor analysis of the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) checklist on item level was performed on data from 335 outpatients with primary OCD. The relationship of demographic and clinical characteristics to the resulting factor scores was examined. A principal component analysis identified the following five consistent symptom dimensions: (1) contamination and cleaning, (2) aggressive, sexual and religious obsessions, (3) somatic obsessions and checking, (4) symmetry and counting/arranging compulsions and (5) high-risk assessment and checking. We observed significant differences in sex distribution, age of onset, Y-BOCS scores and familial prevalence of OCD in relation to the symptom dimensions. These findings provide further evidence for distinct clinical phenotypes in OCD.