Intolerance of uncertainty on distress and impairment: The mediating role of repetitive negative thinking.

Repetitive negative thinking and intolerance of uncertainty are risk and maintenance factors for emotional disorders. Although emerging evidence suggests that intolerance of uncertainty predicts increases in distress through repetitive negative thinking, these relationships have yet to be investigated among veterans. The present study examines if repetitive negative thinking mediates the relationships of intolerance of uncertainty with stress, disordered symptoms and impairment among a mixed clinical sample of veterans. Two hundred and forty-four treatment-seeking veterans with diagnoses of major depressive disorder, panic disorder, or posttraumatic stress disorder completed measures of intolerance of uncertainty, repetitive negative thinking, stress, impairment, depression, panic, and posttraumatic stress prior to receiving treatment. Mediation models revealed indirect effects of intolerance of uncertainty through repetitive negative thinking on stress and impairment in the full sample, and on disordered symptoms in subsamples with major depressive disorder and posttraumatic stress disorder. Conversely, intolerance of uncertainty did not have direct or indirect effects on disordered symptoms in a panic disorder subsample. Findings suggest that repetitive negative thinking and intolerance of uncertainty uniquely contribute to stress, impairment, and disordered symptoms, but repetitive negative thinking, may, in part, drive intolerance of uncertainty's contribution to emotional disorders. Interventions for repetitive negative thinking might improve the efficacy of existing transdiagnostic treatment protocols. Cross-sectional data is a limitation of the present study. Prospective designs in civilian samples can better establish the temporality of these relationships and if they are generalizable to the larger population.