A meta-analysis of the relation of intolerance of uncertainty to symptoms of generalized anxiety disorder, major depressive disorder, and obsessive-compulsive disorder.

Intolerance of uncertainty (IU) has been suggested to reflect a specific risk factor for generalized anxiety disorder (GAD), but there have been no systematic attempts to evaluate the specificity of IU to GAD. This meta-analysis examined the cross-sectional association of IU with symptoms of GAD, major depressive disorder (MDD), and obsessive-compulsive disorder (OCD). Random effects analyses were conducted for two common definitions of IU, one that has predominated in studies of GAD (56 effect sizes) and another that has been favored in studies of OCD (29 effect sizes). Using the definition of IU developed for GAD, IU shared a mean correlation of .57 with GAD, .53 with MDD, and .50 with OCD. Using the alternate definition developed for OCD, IU shared a mean correlation of .46 with MDD and .42 with OCD, with no studies available for GAD. Post-hoc significance tests revealed that IU was more strongly related to GAD than to OCD when the GAD-specific definition of IU was used. No other differences were found in the magnitude of associations between IU and the three syndromes. We discuss implications of these findings for models of shared and specific features of emotional disorders and for future research efforts.