Validating a Measure of Mental Contamination in Adolescent OCD: A Psychometric Study

Mental contamination (MC) refers to a persistent feeling of internal dirtiness triggered by thoughts, images, or memories in the absence of physical contact (Rachman, 2011), often lingering long after a distressing or humiliating event (Coughtrey, 2010). MC is closely linked to obsessive-compulsive disorder (OCD), as intrusive thoughts can lead to compulsive cleaning behaviours aimed at reducing discomfort. More recently, MC has been conceptualised as a broader phenomenon that can appear in both clinical and milder forms. The Vancouver Obsessional Compulsive Inventory – Mental Contamination subscale (VOCI-MC) (Rachman, 2005) has been validated for assessing MC symptoms in adults. However, its suitability for adolescents remains untested. Patient and Public Involvement (PPI), which focuses on centring people with lived experiences in the research design, was carried out. Young people, including those diagnosed with OCD, found the VOCI-MC to be adequate upon a change in wording for one of the questions. Therefore, our study aims to empirically evaluate the psychometric properties of the refined VOCI-MC in 13-18-year-olds using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to assess its potential use in community and clinical settings.