The relationships between obsessive-compulsive symptom dimensions and cognitions in obsessive-compulsive disorder.

Several studies have linked obsessive-compulsive symptoms to specific obsessive-compulsive cognitions, however methodologies have varied, and no study has determined obsessive-compulsive symptoms using the most widely used clinician rating scale, the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Considering that almost all studies that used factor analysis to ascertain OCD symptom dimensions were based on the Y-BOCS and that self-report instruments assessing obsessive-compulsive symptoms correlate poorly with the Y-BOCS, there is a need to use the Y-BOCS to examine the relationship between obsessive-compulsive cognitions and obsessive-compulsive symptom dimensions. This study examined the relationship between five Y-BOCS-derived obsessive-compulsive symptom dimensions and the three obsessive-compulsive cognitive domains identified by the obsessive-beliefs questionnaire (OBQ). The symmetry/ordering symptom dimension was associated with increased perfectionism/intolerance of uncertainty, the unacceptable/taboo thoughts symptom dimension was associated with increased importance/control of thoughts and the doubt/checking symptom dimension was associated with increased responsibility/threat estimation. There was no statistical evidence of an association between any OBQ belief sub-scale and the hoarding symptom dimension nor the contamination/cleaning symptom dimension. The findings encourage symptom-based approaches to cognitive-behavioural therapy for some OCD symptoms and call for further research on cognitions associated with contamination/cleaning symptoms and hoarding.