Symptom dimensions in obsessive-compulsive disorder: phenomenology and treatment outcomes with exposure and ritual prevention

Background: Obsessive-compulsive disorder (OCD) is a severe condition with varied symptom presentations. Currently, the cognitive-behavioral treatment with the most empirical support is exposure and ritual prevention (EX/RP); however, clinical impression and some empirical data suggest that certain OCD symptoms are more responsive to treatment than others.

Methods: Prior work identifying symptom dimensions within OCD is discussed, including epidemiological findings, factor analytic studies, and biological findings. Symptom dimensions most reliably identified include contamination/cleaning, doubt about harm/checking, symmetry/ordering, and unacceptable thoughts/mental rituals. The phenomenology of each of these subtypes is described and research literature is summarized, emphasizing the differential effects of EX/RP and its variants on each of these primary symptom dimensions.

Results: To date it appears that EX/RP is an effective treatment for the various OCD dimensions, although not all dimensions have been adequately studied (i.e. symmetry and ordering).

Conclusions: Modifications to treatment may be warranted for some types of symptoms. Clinical implications and directions for future research are discussed.