Does mental contamination mediate the association between childhood trauma and obsessive-compulsive symptoms in adults?

Previous research has shown that individuals with obsessive-compulsive disorder (OCD) and OCD symptoms have higher rates of childhood trauma. Although it has been suggested that this relationship is due to mental contamination that developed in response to trauma, no studies have investigated the associations between childhood trauma, mental contamination, and OCD, and none have examined whether the relationship between childhood trauma and OCD is mediated by mental contamination. We hypothesized that OCD, childhood trauma, and mental contamination are positively correlated, and that mental contamination would mediate the association between childhood trauma and OCD symptoms We tested these hypotheses in a sample of 245 individuals, which comprised 158 MTurk workers recruited via CloudResearch.com and 87 individuals recruited through social media with OCD diagnoses or OCD symptoms above the clinical cutoff on the Obsessive-Compulsive Inventory-Revised. Participants completed online self-report questionnaires on childhood trauma, mental contamination, and OCD symptoms. The results revealed statistically significant positive correlations between childhood trauma, mental contamination, and OCD, and statistically significant total and indirect effects for the simple mediational model. Exploratory re-analyses with participants who had high OCD symptoms (n = 87) showed similar results. Our research shows that the association between childhood trauma and OCD may be explained by mental contamination. We recommend that mental contamination should be assessed and addressed in OCD patients with a history of childhood trauma.