(PS2-64) Accounting for Depressive Symptoms in the Study of Intolerance of Uncertainty & Obsessive-compulsive Symptoms

Intolerance of uncertainty (IU)—the extent to which one responds negatively to a lack of certainty—is a transdiagnostic cognitive vulnerability factor. It is particularly salient to obsessive-compulsive disorder (OCD), generalized anxiety disorder (GAD), and depression (Gentes & Ruscio, 2011). That noted, the extant literature is mixed regarding the association between specific OC symptom dimensions and the Intolerance of Uncertainty Scale (IUS-12)—both its total score and its subscales: Prospective IU (IUS-P; distress related to potential uncertainty in the future) and Inhibitory IU (IUS-I; functional and cognitive impairment in uncertain situations). For example, Jacoby et al. (2013) controlled for depression and found that IU predicted only harm and symmetry OC symptoms, but Pinciotti et al. (2021) did not control for depression and found that IU predicted all assessed OC symptoms. Notably, Pinciotti et al. (2021) also found that inhibitory IU—which Jensen et al. (2016) found may be particularly associated with depression—independently predicted unacceptable thought and contamination OC symptoms. Since IU did not predict unacceptable thought and contamination OC symptoms when Jacoby et al. (2013) controlled for depression, these discrepant findings may be due to the relationship between inhibitory IU and depression. Our study sought to investigate the extent to which this methodological difference might affect conclusions, by evaluating the correlations between the IUS-12 (and its subscales) and OC symptom dimensions before and after partialling out depression.

Participants (N = 257) were undergraduate students who completed a series of questionnaires, including the IUS-12, the Dimensional Obsessive-Compulsive Scale (DOCS), and the Depression, Anxiety, and Stress Scales Depression scale (DASS-D).

Zero-order correlations revealed that the IUS-12 was significantly correlated with the DOCS total score, as well as with all four subscales: Contamination, Harm, Symmetry, and Unacceptable Thoughts. The DOCS total score was more strongly correlated with IUS-I (r = .54) than with IUS-P (r = .43; z = 2.32, p = .013). Similar differences were found between the IUS-12 subscales and both Harm and Symmetry. This pattern extended to the DASS-D, as it also was more strongly associated with IUS-I (r = .59) than IUS-P (r = .48), z = 2.32, p = .01. After partialling out the DASS-D, all but one of the between-subscale differences were rendered non-significant. The exception was that DOCS Symmetry still was more strongly associated with IUS-I (r = .28) than IUS-P (r = .15), z = 1.95, p = .025.

These results indicate that depression may explain disparate findings regarding the extent to which IU—particularly inhibitory IU—predicts various OC symptom dimensions. Statistically controlling for depression in the analysis substantially changed findings regarding between-subscale differences. Thus, researchers studying IU should carefully consider how the data analytic approach accounts for the large covariance among OC and depressive symptoms and the potential confounding effects this may have on conclusions. Future research should investigate whether this is a meaningful conceptual issue worth pursuing or merely a measurement artefact.