The role of intolerance of uncertainty in current and remitted internalizing and externalizing psychopathology.

Intolerance of uncertainty (IU) is a putative key, transdiagnostic factor in internalizing psychopathologies. However, it is unclear if elevated levels of IU, as measured by the Intolerance of Uncertainty Scale, short form (IUS-12) and its subscales (prospective and inhibitory IU), persist into remission of internalizing psychopathologies (or particular types of internalizing psychopathologies; e.g., fear vs. distress-misery disorders). It is also unknown if IU is specifically characteristic of internalizing (vs. externalizing) psychopathology and whether this relationship is independent of neuroticism/negative affectivity (N/NA). A large community sample (n = 517) completed a diagnostic interview and self-report measures of IU and N/NA. Results indicated that, independent of N/NA, IU was elevated in current fear and distress/misery disorders, but not externalizing disorders. Individuals with remitted fear disorders also displayed significantly elevated levels of IU in comparison to healthy controls after adjusting for levels of N/NA. In terms of subscales, elevated levels of inhibitory IU, and not prospective IU, demonstrated more reliable relationships with internalizing psychopathologies. In summary, IU was more consistently related to fear disorders, demonstrated incremental validity over and above the effects of N/NA, and may be a key, transdiagnostic mechanism in fear disorders.