Uncertainty Intolerance Higher in Outpatients with ADHD

Adult psychiatric outpatients with attention-deficit/hyperactivity disorder (ADHD) had higher levels of uncertainty intolerance compared with outpatients without ADHD, according to a poster presented at the virtual 2021 American Psychiatric Association Annual Meeting.

“[E]merging evidence suggests that intolerance of uncertainty is related to risky/impulsive decisions, and that this effect is driven by the desire to mitigate uncertainty-driven distress,” wrote researchers from the START Clinic for Mood and Anxiety Disorders in Toronto, Ontario, Canada. “Despite the recognition that decision-related deficits and impulsivity are core symptoms of ADHD, research has seldom explored intolerance of uncertainty within an adult ADHD population."

To investigate the relationship between ADHD and intolerance of uncertainty, researchers compared 217 adult outpatients with ADHD with 487 adult outpatients at the same psychiatric clinic without ADHD. Participants completed the self-administered Intolerance of Uncertainty Scale, which evaluates both impaired functioning in response to uncertainty (inhibitory intolerance of uncertainty) and the desire for predictability (prospective intolerance of uncertainty).

According to the poster, patients with ADHD had higher total, inhibitory, and prospective intolerance of uncertainty compared with patients without ADHD. Patients with ADHD and a comorbid anxiety disorder had higher total score on the Intolerance of Uncertainty Scale compared with patients with ADHD only, an anxiety disorder only, or neither disorder.

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Generalized anxiety disorder and post-traumatic stress disorder (PTSD) predicted increased uncertainty intolerance in patients with ADHD. Meanwhile in patients without ADHD, generalized anxiety disorder, obsessive-compulsive disorder, and social anxiety disorder predicted increased uncertainty intolerance in patients without ADHD.

Comorbid generalized anxiety disorder, PTSD, and social anxiety disorder stood out as significant predictors of increased uncertainty intolerance in patients with comorbid ADHD and together accounted for 18.9% of the variance in total intolerance of uncertainty, a hierarchical stepwise regression indicated.

“Intolerance of uncertainty may serve as a potential mechanism underlying comorbid ADHD and anxiety,” researchers advised, “and more broadly, the findings support intolerance of uncertainty as a transdiagnostic factor across various forms of externalizing and internalizing psychopathology.”

—Jolynn Tumolo

Reference

Mason G, Lokuge S, Sternat T, Katzman M, Fotinos K. Intolerance of uncertainty in attention-deficit/hyperactivity disorder and comorbid anxiety disorders. Poster presented at the American Psychiatric Association Annual Meeting; May 1-3, 2021; Virtual.