It's the feeling inside my head: a qualitative analysis of mental contamination in obsessive-compulsive disorder

It was recently proposed that feelings of dirtiness and pollution can arise in the absence of physical contact with a contaminant. At present, there is limited data regarding the qualitative features of this construct of "mental contamination", although it is hypothesized to be particularly relevant to Obsessive Compulsive Disorder (OCD), where compulsive washing in response to contamination fear is a common symptom presentation (Rachman, 2006).

The aim of this research was to explore the qualitative features of mental contamination in 20 people with contamination-based OCD, using a semi-structured interview.

All participants reported times when they had felt dirty or contaminated in the absence of physical contact with a dirty or dangerous object. Mental contamination generated diffuse feelings of internal dirtiness not localized to the hands, which evoked urges to wash (100% participants), neutralize (80% participants) and avoid (85% participants).

In support of the theory outlined by Rachman (2006), mental contamination was found to take a number of forms, be primarily associated with a human source, generate internal dirtiness and cause emotional distress and urge to wash. The clinical implications of these findings are discussed and ideas for future research are proposed.