(PS3-C56) Rumination and Metacognitions Mediate the Relationship Between Intolerance of Uncertainty and OCD Symptoms

Intolerance of uncertainty (IU) is an individual's dispositional incapacity to endure the possibility of a negative event occurring, irrespective of the likelihood of that occurrence (Carleton et al., 2007). IU is thought to be a vulnerability and maintenance factor in a variety of disorders such as depression, generalized anxiety disorder (GAD), and obsessive-compulsive disorder (OCD). In an erroneous effort to quell IU-related discomfort, these individuals often engage in disorder-specific ruminative processes (i.e., rumination, worry, obsessional thinking). Indeed, research has demonstrated that rumination mediates the relationship between IU and symptom severity for both depression and GAD. However, the explanatory factors underlying the relationship between IU and OCD symptoms are less clear.

Metacognition broadly refers to one’s understanding of their cognitive processes. Individuals with OCD tend to perceive meaning in their obsessive thoughts (e.g., “I thought of stabbing someone, I must be a violent person”) which leads to compulsive rituals and mental acts (e.g., mental review/checking emotions around the thought of stabbing someone). Thus, it is likely that both metacognitions about the meaning of thoughts and ruminative processes play a role in the relationship between IU and symptom severity in OCD.

To evaluate the possible mechanisms underlying the relationship between IU and OCD symptoms, the current study tested a parallel mediation model to understand the relative contributions of rumination and metacognitive beliefs in a large, unselected community sample. Participants (N = 245; M age = 43.58, SD = 10.68) recruited via Amazon’s Mechanical Turk completed The Dimensional Obsessive-Compulsive Scale (DOCS), Intolerance of Uncertainty Scale (IUS-12), The Metacognition Questionnaire 30 (MCQ-30), and The Ruminative Thought Style Questionnaire (RTS). Cross-sectional parallel mediation analyses were conducted using the PROCESS macro for SPSS (Model 4). The total effect of IU on OCD symptoms was significant which replicates previous literature, b = .2268, s.e. = .0503, p < .0001. Individuals who scored higher on IU were more likely to endorse ruminative thought styles, b = 1.7072, s.e. = .1113, p < .0001. Likewise, those higher in IU were more likely to assign meaning to their thoughts and worries, b = .8326, s.e. = .0578, p < .0001. However, when both rumination and metacognitive beliefs were included in the model, the direct effect of IU on OCD was not significant (p = .06) indicating full mediation, b = -.1301, s.e. = .0698, 95% CI [-.2676, .0074]. Examination of both rumination (b=.2165, s.e.=.0514, 95% CI [.1222, .3228]), and metacognitive beliefs (b = .1403, s.e. = .0502, 95% CI [ .0493, .2467]) suggested parallel mediation of the IU – OCD symptom relationship.

Broadly, findings suggest that the relationship between IU and OCD symptoms may be explained by two relevant cognitive processes: the style of engagement with thoughts (rumination) and the meaning assigned to thoughts (metacognition). Future studies examining the replicability of findings in longitudinal data and clinical samples are needed. Clinical and transdiagnostic implications, alongside observed nuances in mediator subscales, will be discussed.