title: Further support for five dimensions of obsessive-compulsive symptoms.
abstract: Attempts to explain the phenotypic heterogeneity of obsessive-compulsive disorder (OCD) have resulted in three to six OCD symptom dimensions. This study aimed to clarify the nature of these symptom dimensions using a self-report instrument (Vancouver Obsessional Compulsive Inventory [VOCI]) in addition to the clinician-rated Yale-Brown Obsessive Compulsive Scale-Symptom Checklist (YBOCS-SC). Participants (N = 154) were recruited to a study designed to specifically assess OCD symptom dimensions. Symptoms assessed via the YBOCS-SC and the VOCI were subjected to principal components analysis (PCA). Linear regression was used to assess the relationship between the YBOCS-SC-derived symptom dimensions and the VOCI symptom subscales. PCA of the YBOCS-SC and the VOCI revealed five OCD symptom dimensions that explained 68% and 60% of the variance, respectively. The results also supported a distinction between the doubt/checking symptom dimension and the unacceptable/taboo thoughts dimension that includes mental rituals. The YBOCS-SC-derived symptom components were predicted by their respective VOCI symptom subscale scores.
authors.affiliation: Discipline of Psychiatry, Sydney Medical School-Nepean, University of Sydney, Sydney/Penrith, Australia. vbrakoulias@bigpond.com
authors.forename: Vlasios
authors.initials: V
authors.lastname: Brakoulias
authors.forename: Vladan
authors.initials: V
authors.lastname: Starcevic
authors.forename: David
authors.initials: D
authors.lastname: Berle
authors.forename: Peter
authors.initials: P
authors.lastname: Sammut
authors.forename: Denise
authors.initials: D
authors.lastname: Milicevic
authors.forename: Karen
authors.initials: K
authors.lastname: Moses
authors.forename: Anthony
authors.initials: A
authors.lastname: Hannan
authors.forename: Andrew
authors.initials: A
authors.lastname: Martin
mesh_terms: D057189:Checklist; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000523:psychology*; D025341:Principal Component Analysis; D011569:Psychiatric Status Rating Scales