Does intolerance of uncertainty mediate improvement in anger during group CBT for GAD? A preliminary investigation

BACKGROUND: Individuals with generalized anxiety disorder (GAD) have elevated intolerance of uncertainty (IU) and anger, and IU mediates the relationship between GAD symptoms and anger. AIMS: The current pilot study examined whether group cognitive behavioural therapy (CBT) improves anger in people with GAD, and the degree to which change in IU mediates improved anger. METHOD: Individuals diagnosed with GAD completed measures of worry, IU, and facets of anger, before and at the end of group CBT for GAD. RESULTS: Worry, IU, and internally felt and outwardly expressed anger, reduced significantly over treatment, but anger control (inwardly and outwardly) did not. CBT for GAD led to improvement in both internally felt and outwardly expressed anger, even though anger is not directly targeted in this treatment. Improvement in IU significantly mediated improvement in internally felt and outwardly expressed anger. CONCLUSIONS: This preliminary study contributes to the literature on the importance of IU in understanding worry and other symptoms such as elevated anger, experienced by people with excessive worry.