• intolerance of uncertainty;
  • anxiety;
  • depression;
  • psychotherapy outcome

Intolerance of uncertainty (IU) is a characteristic predominantly associated with generalized anxiety disorder (GAD); however, emerging evidence indicates that IU may be a shared element of emotional disorders.


This study aimed to examine IU across diagnostic categories, change in IU during transdiagnostic treatment, and the relationship between change in IU and treatment outcome.


Patients diagnosed with heterogeneous anxiety and depressive disorders received up to 18 weeks of a transdiagnostic cognitive-behavioral therapy intervention. Patient self-reported IU and self-report and clinician-rated symptom/functioning measures were administered at pretreatment and posttreatment.


When controlling for negative affectivity, IU correlated with measures of depressive symptoms and worry severity at pretreatment. Patients with GAD and panic disorder exhibited the highest pretreatment IU scores, yet IU scores did not differ significantly based on the presence or absence of a specific diagnosis. A significant decrease in IU was observed, and change in IU was related to reduced anxiety and depressive symptom levels at posttreatment across diagnostic categories.


Change in IU can be observed across problem areas in transdiagnostic treatment and such change is correlated with treatment outcome.