Meta-analysis of the symptom structure of obsessive-compulsive disorder.
ABSTRACT 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.
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.
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.
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.
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ABSTRACT: The Dimensional Obsessive-Compulsive Scale (DOCS) is a promising measure of obsessive-compulsive disorder (OCD) symptoms but has received minimal psychometric attention. We evaluated the utility and reliability of DOCS scores. The study included 832 students and 300 patients with OCD. Confirmatory factor analysis supported the originally proposed four-factor structure. DOCS total and subscale scores exhibited good to excellent internal consistency in both samples (α = .82 to α = .96). Patient DOCS total scores reduced substantially during treatment (t = 16.01, d = 1.02). DOCS total scores discriminated between students and patients (sensitivity = 0.76, 1 - specificity = 0.23). The measure did not exhibit gender-based differential item functioning as tested by Mantel-Haenszel chi-square tests. Expected response options for each item were plotted as a function of item response theory and demonstrated that DOCS scores incrementally discriminate OCD symptoms ranging from low to extremely high severity. Incremental differences in DOCS scores appear to represent unbiased and reliable differences in true OCD symptom severity. © The Author(s) 2014.Assessment 11/2014; · 3.29 Impact Factor
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ABSTRACT: Disgust propensity is associated with contamination/washing symptoms.•Reduction in disgust propensity is associated with improvement in contamination/washing symptoms.•Disgust propensity may be a marker specific to the contamination/washing subtype of OCD.Journal of Obsessive-Compulsive and Related Disorders 11/2014; 4. · 0.81 Impact Factor
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ABSTRACT: Objective: The purpose of this study was to examine the acute effectiveness of manualized exposure-based CBT with a family-based treatment, as an initial treatment for pediatric OCD delivered in regular community child and adolescents outpatient clinics. The report summarizes outcome of the first treatment step in the NordLOTS, which was conducted in Denmark, Sweden and Norway. Method: 269 participants, age 7–17, with OCD, received treatment for 14 weekly sessions. Treatment response was defined as CY-BOCS score of ≤15 at post treatment. Results: 241 participants (89.6%) completed all 14 weeks of treatment. Treatment response, among the participants was 72.6% (95% CI 66.7%-77.9%). Mixed effects model revealed a statistically significant effect of time F(1,479)=130.434. Mean symptom reduction on the CY-BOCS was 52.9% (SD=30.9). The estimated within-group effect size between baseline and post treatment was 1.58 (95% CI: 1.37-1.80). Conclusion: This study found that manualized CBT can be applied effectively in community mental health clinics. These findings underscores the feasibility of implementing exposure-based CBT for pediatric OCD in a regular child and adolescent mental health setting. Clinical Trials Registration Information: This study was registered in Current Controlled Trials; Nordic Long-term Obsessive compulsive disorder (OCD) Treatment Study (www.controlled-trials.com ISRCTN66385119). Keywords: Child and adolescent; obsessive-compulsive disorder; Cognitive-behavioral therapy; Exposure and response prevention; Treatment outcome.Behaviour Research and Therapy 11/2014; · 3.85 Impact Factor