Obsessive-compulsive disorder, as the name suggests, involves both obsessions–intrusive worries about bad things happening–and compulsions, which are intended to prevent the feared outcomes.
Or does it? Based on the diagnostic criteria in DSM-5, OCD can be diagnosed if obsessions or compulsions are present. Accordingly, a significant number of OCD sufferers describe themselves as “pure obsessional” or “Pure O,” meaning they have obsessions without compulsions.
However, what appears to be “Pure O” typically turns out to involve mental compulsions (like saying a ritualized prayer), which functionally are the same as compulsions that others can see (such as repetitive hand washing). Both types of compulsions are meant to reduce the chance of something bad happening, and to reduce the person’s distress.
Every instance of “Pure O” that I’ve encountered has included the presence of mental compulsions, which is in line with research findings. In a study (1) of over 1000 OCD sufferers, every single person was found to have both obsessions and compulsions–including the 1 percent of individuals who initially thought they had only obsessions. A related study (2) reported that individuals who supposedly have “Pure O” engage in mental compulsions and reassurance seeking.
The study authors strongly recommended that the updated OCD criteria reflect their, and others’, findings. However, for reasons that are unclear the DSM-5 work group that updated the OCD criteria chose not to require the presence of both obsessions and compulsions for an OCD diagnosis.
Does it matter that “Pure O” actually includes rituals, or is it an academic distinction without a difference? In practice it probably matters a great deal. The psychological treatment of choice for OCD is exposure and response prevention (ERP), and preventing the compulsive response is a crucial part of the treatment. If the OCD sufferer (or therapist) doesn’t recognize mental compulsions and reassurance seeking as compulsions, then treatment will not effectively deal with these behaviors. As a result the person is likely to stay stuck with the OCD.
When the compulsions are recognized for what they are, they can be treated just like any other ritual in ERP (see this related post).
1. Leonard, R. C., & Riemann, B. C. (2012). The co-occurrence of obsessions and compulsions in OCD. Journal of Obsessive-Compulsive and Related Disorders, 1, 211-215.
2. Williams, M. T., Farris, S. G., Turkheimer, E., et al. (2011). Myth of the pure obsessional type in obsessive-compulsive disorder. Depression and Anxiety, 28, 495-500.