(PS7-C71) The Roles of Behavioral Inhibition and Intolerance of Uncertainty in Predicting Obsessive Compulsive Spectrum Symptom Severity

Background: Behavioral inhibition, the sensitivity to and avoidance of novel stimuli, has been identified as a risk factor for the development of anxiety and obsessive compulsive (OC) disorders (Coles et al., 2006; Sportel et al., 2011). Intolerance of uncertainty is an additional known risk factor for obsessive compulsive disorder (OCD) and has been highlighted in the relationship between behavioral inhibition and general anxiety disorder (Zdebik et al., 2022). However, despite evidence linking behavioral inhibition, intolerance of uncertainty, and OC spectrum disorders separately, no research has examined the three together. Thus, the purpose of this study was to examine the roles of behavioral inhibition and intolerance of uncertainty in predicting OCD, obsessive compulsive personality disorder (OCPD), and hoarding symptom severity. 

Method: 195 clinical participants were recruited as part of a larger longitudinal study on OC spectrum and anxiety disorders. The following measures were administered: the Behavioral Inhibition Scale, the 12-item Intolerance of Uncertainty Scale, the Yale-Brown Obsessive-Compulsive Scale, the Pathological Obsessive Compulsive Personality Scale, and the Hoarding Rating Scale. Based on prior research, behavioral inhibition and intolerance of uncertainty were selected as potential predictors for hierarchical linear regression analyses assessing their relationships with year 1 and 2 OC spectrum symptom severity.

Results: Baseline intolerance of uncertainty significantly predicted greater OCD symptom severity at year 1 (p = .006) and year 2 (p = .007). Intolerance of uncertainty was the strongest predictor across both timepoints, significantly explaining an additional 8.15% (F(1, 82) = 7.88, p < .001) and 10% (F(1, 64) = 7.76, p = .007) of the variance in OCD symptom severity at years 1 and 2, respectively, than behavioral inhibition alone. Intolerance of uncertainty had the largest effect in OCPD, significantly accounting for 28.41% more variance at year 1 (F(1, 82) = 36.37, p < .001) and 26.83% more variance at year 2 (F(1, 63) = 25.96, p < .001) than only behavioral inhibition. Hoarding alone was not significantly predicted by intolerance of uncertainty at either year 1 (p = .06) or year 2 (p = .98), and was significantly predicted by behavioral inhibition at year 1 only (p = .04,  r = -0.21).

Conclusion:  Intolerance of uncertainty accounted for significantly more variance in OCD and OCPD severity than behavioral inhibition alone, suggesting that behavioral inhibition may not be uniquely predictive of OCD and OCPD severity over time. Additionally, intolerance of uncertainty may be an especially important factor in OCPD. Hoarding, however, differed in that it was not strongly related to either behavioral inhibition or intolerance of uncertainty, which may be reflective of the distinctions existing between hoarding disorder and OCD and OCPD. These preliminary findings suggest that, although behavioral inhibition may impact symptom severity, intolerance of uncertainty may be a more beneficial treatment target for OCD and OCPD. Given our findings, future research should seek to further understand the role of intolerance of uncertainty in OC spectrum conditions.