This meta-analysis synthesized data from 138 independent samples involving a total of 28,693 individuals to evaluate the structural relationship between intolerance of uncertainty (IU), worry, and various anxiety disorders. The study specifically examined conditions including Generalized Anxiety Disorder (GAD), Post-Traumatic Stress Disorder (PTSD), Social Anxiety Disorder, Obsessive-Compulsive Disorder (OCD), and Panic Disorder, as well as non-specific anxiety. The primary objective was to establish a structural model of the path from IU through worry to specific anxiety outcomes.
The analysis focused on the correlation between IU and worry, which showed a robust association with an effect size of r =.59. Furthermore, the study examined the direct associations between IU and specific clinical diagnoses. The strongest association in the hierarchy was found between IU and GAD (r =.54). Other significant associations included IU and non-specific anxiety (r =.48), IU and PTSD (r =.46), and IU and social anxiety disorder (r =.45). Weaker associations were observed for IU and OCD (r =.41) and the weakest link in the hierarchy was found between IU and panic disorder (r =.27).
A critical component of the analysis was determining the mediating role of worry. Worry demonstrated a strong association with GAD (r =.67). The meta-analytic structural equation modeling indicated that worry served as a partial mediator for several pathways. Specifically, worry partially mediated the IU to GAD relationship (r =.32), the IU to non-specific anxiety relationship (r =.22), the IU to social anxiety disorder relationship (r =.17), and the IU to panic disorder relationship (r =.15). In cases of PTSD and OCD, worry also served as a partial mediator with effect sizes of r =.14 and r =.13, respectively.
Additional analysis looked at moderating factors. It was noted that overlapping self-report measures for IU, GAD, non-specific anxiety, and worry resulted in significantly stronger effects (p <.05). This suggests that measurement overlap may influence the observed strength of associations between these constructs.
These findings provide a transdiagnostic framework for understanding how patients process uncertainty. By identifying IU as a distal factor and worry as a proximal cognitive process, the results suggest that while both are relevant to anxiety, they function differently in the clinical hierarchy. The varying degrees of mediation across different disorders (ranging from r =.13 to r =.32) may reflect differences in how specific conditions manifest cognitively.
Methodologically, the study is based on a meta-analysis of 738 effect sizes from 115 studies. While this provides a large sample size and high statistical power, it is important to note that these results are based on associations and mediation models rather than primary clinical trials. Therefore, the data do not establish causality between IU, worry, and anxiety symptoms.
Clinical implications for practice include the identification of IU as a potential target for early intervention or as a marker for risk in patients with GAD, PTSD, social anxiety, OCD, and panic disorder. Understanding the role of worry as a mediator may help clinicians tailor cognitive interventions to address specific proximal processes. However, since these results are meta-analytic, they should be interpreted as evidence of a structural relationship rather than a direct causal pathway for treatment planning.
Several questions remain regarding the practical application of these findings. Specifically, it is not yet clear how targeting IU specifically—rather than general worry—impacts long-term outcomes in patients with panic disorder or OCD, where the association was weaker. Additionally, the impact of measurement overlap on reported effect sizes suggests that future research should utilize more distinct instruments to clarify the unique contribution of each construct.
How this fits prior evidence
How this fits prior evidence
This meta-analysis provides a transdiagnostic framework for anxiety disorders, including PTSD and OCD. It complements previous findings where acupoint stimulation was noted as an adjunct for OCD (reducing symptoms by 3.14 points on Y-BOCS) and VRET was shown to reduce PTSD symptoms in military veterans. While those studies focused on specific interventions, this meta-analysis identifies the underlying cognitive mechanisms—specifically intolerance of uncertainty and worry—that may drive these conditions.
