Mental contamination and scrupulosity: Evidence of unique associations among Catholics and Protestants

• Mental contamination was positively associated with scrupulosity.
• Observed association was not accounted for by relevant covariates.
• Pattern of results nearly identical among Catholics and Protestants.

Mental contamination refers to an internal sense of dirtiness and research supports its relevance to obsessive–compulsive disorder (OCD). Scrupulosity is a moral/religious subtype of OCD and yet no known published study has examined an association between mental contamination and scrupulosity. The present study sought to fill this gap in the literature using a sample of self-identifying Catholic (n=102) and Protestant (n=128) community adults. Mental contamination shared a strong association with scrupulosity in the present study and this association was unaccounted for by overestimation of threat, responsibility, importance/control of thoughts, perfection/certainty, thought-action fusion, contact contamination, religiosity, or negative affect. In fact, mental contamination was the only targeted variable that shared a unique association with scrupulosity across all analyses. A nearly identical pattern of results emerged among Catholic and Protestant respondents. Implications of incorporating mental contamination into existing conceptualizations and treatments of scrupulosity are discussed.