Temporal stability of symptom dimensions in adult patients with obsessive-compulsive disorder.

Background: Although symptoms of obsessive-compulsive disorder (OCD) are heterogeneous, considerable advances have been made in subtyping OCD based on factor-analysed symptom dimensions. However, there is very little empirical data on the longitudinal course of symptom dimensions in adult OCD.

Methods: We examined prospectively the temporal symptom stability in adult OCD patients. Of 54 baseline OCD inpatients, 43 (80%) were re-assessed with the Yale-Brown Obsessive-Compulsive Scale symptom checklist after 6 years on average.

Results: Significant changes occurred within the symptom dimensions aggressive/checking, symmetry/ordering, and contamination/cleaning, whereas the others (hoarding, sexual/religious) remained unchanged from baseline to follow-up. Shifts between different dimensions from baseline to follow-up were rare, the score of each dimension at follow-up was most strongly predicted from the score of the same dimension at baseline.

Limitations: The main limitation of the present study is the relatively small sample size. Furthermore, not the same raters conducted the baseline and follow-up assessments.

Conclusions: Symptom dimensions seem to be remarkably stable over several years in adult OCD, despite various treatments and significant improvements in symptom severity. This underlines the usefulness of these symptom dimensions for studies of biological and genetic markers, comorbidity and treatment response predictors.