Developing scales measuring disorder-specific intolerance of uncertainty (DSIU): a new perspective on transdiagnostic.

Intolerance of uncertainty (IU) is a construct of growing prominence in literature on anxiety disorders and major depressive disorder. Existing measures of IU do not define the uncertainty that respondents perceive as distressing. To address this limitation, we developed eight scales measuring disorder-specific intolerance of uncertainty (DSIU) relating to various anxiety disorders and major depressive disorder. We used exploratory factor analysis and item characteristic curves in two large undergraduate samples (Ns=627 and 628) to derive eight three-item DSIU scales (24 items total) that exhibited excellent psychometric properties. Confirmatory factor analysis supported the factor structures of the scales and the transdiagnostic nature of IU. Each scale predicted unique variance in its respective symptom measure beyond a traditional measure of IU. DSIU represents a theoretically proximal and causal intermediary between known vulnerability factors and disorder symptomatology. The DSIU scales can be used to advance theories of psychopathology and inform case conceptualization and treatment planning.