The relationship between obsessive compulsive disorder and mental contamination (MC): Psychometric properties of vancouver obsessive compulsive inventory-MC scale and thought-action fusion-contamination scale

Abstract

Objective: Mental contamination is defined as feelings of internal dirtiness in absence of actual contact with a dirty physical object or a person. Mental contamination is considered to play an important role in maintenance and persistence of obsessive compulsive disorder (OCD). This study aimed to examine psychometric properties of the Turkish version of two objective measures of mental contamination: Vancouver Obsessive Compulsive Inventory-Mental Contamination Scale (VOCI-MC) and Thought-Action Fusion-Contamination Scale (TAF-CS). Method: The participants were 255 university students (183 females and 70 males) with the age range of 18-28 years. The participants were asked to fill out the questionnaire set consisted of VOCI-MC, TAF-CS, Thought-Action Fusion Scale (TAFS), Disgust Scale-Revised, Trait Anger Expression Inventory and Obsessive Compulsive Inventory-Revised (OCI-R). Results: Reliability analyses indicated that internal consistency of VOCI-MC and TAF-CS were 0.93 and 0.92, and test-retest reliabilities were 0.79 and 0.61, respectively. Consistent with the original study, the results of explanatory and confirmatory factor analysis indicated that both scales had one factor structure. Convergent and divergent validity analyses revealed that both scales were positively correlated with OCI-R total scores and its subscales as well as TAF total score and its subscales; but this relationship was significantly less strong for Trait Anger and Disgust Sensitivity. While VOCI-MC significantly predicted OCD symptomatology, TAF-CS had no predictive power in this regard. Conclusions: The results support that psychometric properties of the Turkish versions of the scales meet acceptable standards for validity and reliability, and therefore can be used among Turkish population.