The nature and correlates of avoidance in obsessive-compulsive disorder.

Objectives: Avoidance in obsessive-compulsive disorder (OCD) has been neglected by research. This study aimed (i) to collect information on the nature and frequency of avoidance in people with OCD and ascertain the types of obsessions related to avoidance; (ii) compare OCD individuals with and without avoidance, and (iii) determine predictors of avoidance in people with OCD.

Method: A total of 124 OCD adults underwent a comprehensive assessment. Participants were asked whether they engaged in any avoidance behaviour because of their OCD, and the nature and number of instances of such avoidance were recorded. The instances of avoidance were grouped according to the type of obsession and compulsion that they were related to.

Results: A total of 74 (59.7%) participants reported OCD-related avoidance. Avoidance was most commonly related to contamination obsessions. Almost 80% of all contamination obsessions and more than 50% of all aggressive obsessions were associated with avoidance, and contamination obsessions were significantly more common among the participants with avoidance. In contrast, very few obsessions about a need to collect and keep objects and obsessions about a need for ordering, arranging and doing things right or in an exact way were associated with avoidance; these types of obsessions were also significantly more common among the participants without avoidance. The strongest predictor of avoidance was the presence of contamination obsessions. Participants with avoidance had a significantly more severe OCD than those without avoidance.

Conclusions: Avoidance is common in OCD, and it is particularly frequently associated with contamination obsessions. There is a weak link between avoidance and hoarding and between avoidance and ordering/arranging/symmetry obsessions and compulsions. These results, along with the finding that OCD with avoidance is a more severe illness, have implications for the future diagnostic criteria, description, subtyping and treatment of OCD and for its relationship with other anxiety disorders.