Meta-Analysis of the Symptom Structure of Obsessive-Compulsive Disorder

• Published in: The American journal of psychiatry Vol. 165; no. 12; pp. 1532 - 1542
• Main Authors: Bloch, Michael H., Landeros-Weisenberger, Angeli, Rosario, Maria C., Pittenger, Christopher, Leckman, James F.
• Format: Journal Article
• Language: English
• Published: Arlington, VA American Psychiatric Association 01.12.2008
• Subjects: Adult and adolescent clinical studies; Anxiety disorders. Neuroses; Biological and medical sciences; Clinical trials; Diagnostic and Statistical Manual of Mental Disorders; Factor Analysis, Statistical; Humans; International Classification of Diseases; Matrix; Medical imaging; Medical sciences; Meta-analysis; Neuroses; Obsessive compulsive disorder; Obsessive-Compulsive Disorder - diagnosis; Obsessive-Compulsive Disorder - psychology; Obsessive-compulsive disorders; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Religion; Severity of Illness Index; Studies; Surveys and Questionnaires; Systematic review; Obsessive compulsive disorder; Symptomatology; Review; Anxiety disorder; Metaanalysis
• ISSN: 0002-953X; 1535-7228; 1535-7228
• DOI: 10.1176/appi.ajp.2008.08020320

Objective: OCD is a clinically heterogeneous condition. This heterogeneity has the potential to reduce power in genetic, neuroimaging, and clinical trials. Despite a mounting number of studies, there remains debate regarding the exact factor structure of OCD symptoms. The authors conducted a meta-analysis to determine the factor structure of the Yale-Brown Obsessive Compulsive Scale Symptom Checklist. Method: Studies were included if they involved subjects with OCD and included an exploratory factor analysis of the 13 Yale-Brown Obsessive Compulsive Scale Symptom Checklist categories or the items therein. A varimax-rotation was conducted in SAS 9.1 using the PROC FACTOR CORR to extract factors from sample-size weighted co-occurrence matrices. Stratified meta-analysis was conducted to determine the factor structure of OCD in studies involving children and adults separately. Results: Twenty-one studies involving 5,124 participants were included. The four factors generated were 1) symmetry: symmetry obsessions and repeating, ordering, and counting compulsions; 2) forbidden thoughts: aggression, sexual, religious, and somatic obsessions and checking compulsions, 3) cleaning: cleaning and contamination, and 4) hoarding: hoarding obsessions and compulsions. Factor analysis of studies including adults yielded an identical factor structure compared to the overall meta-analysis. Factor analysis of child-only studies differed in that checking loaded highest on the symmetry factor and somatic obsessions, on the cleaning factor. Conclusions: A four-factor structure explained a large proportion of the heterogeneity in the clinical symptoms of OCD. Further item-level factor analyses are needed to determine the appropriate placement of miscellaneous somatic and checking OCD symptoms.