Anxiety disorders have been estimated to impact roughly 1 in 5 (19%) adults in the United States over the past year, and almost a third (31%) of adults in the United States over the course of their life. Further, these disorders are impairing to individuals; 23% of individuals with anxiety disorders describing their impairment as serious. Given this public health impact, it is crucial, that interventions are designed to alleviate symptoms of anxiety, or to reduce risk factors that may predispose individuals to develop anxiety. Further, it is expected that the COVID-19 will have long-lasting impacts on mental concerns worldwide. With these concerns come new opportunities to improve mental health care, through ultra-brief, self-paced, web-based interventions. These interventions are ideal to increase access to care given their high dissemination value and low cost. Building on prior experimental and intervention work conducted by Dr. Allan, we aim to conduct pilot testing of an ultra-brief, CBT-informed intervention targeting intolerance of uncertainty, or an extreme aversion to and fear of uncertainty.

Intolerance of uncertainty is an ideal construct to target in a broad web-based intervention given theoretical and empirical links between intolerance of uncertainty and a broad spectrum of anxiety and related disorders. Theoretically, intolerance of uncertainty amplifies the experience of stress and anxiety causing people to engage in maladaptive cognitive (e.g., worry) and behavioral (e.g., checking, avoidance) strategies to reduce distress, preventing an opportunity to habituate to the uncertainty. Empirically, a recent meta-analysis reported effect sizes (ds) ranging from .4 to .6 across generalized anxiety disorder, major depression, obsessive compulsive disorder, social anxiety disorder, panic disorder and agoraphobia, and eating disorders. Other studies have implicated intolerance of uncertainty in posttraumatic stress disorder as well as suicidal thought and behavior. More recent evidence has demonstrated that intolerance of uncertainty is not only a "fundamental fear" underlying anxiety disorder etiology but has also been implicated in a host of other mental health problems, including substance use. We recently examined the impact of intolerance of uncertainty on anxiety and depression during the COVID-19 pandemic over three months and found intolerance of uncertainty was concurrently associated with and significantly predictive of symptoms of generalized anxiety disorder and depression. Therefore, not only is there strong theoretical and empirical support for intolerance of uncertainty as a transdiagnostic risk factor for anxiety and related conditions, but there is also evidence that supports intolerance of uncertainty as particularly relevant to the current environmental conditions due to COVID-19.

To date, we have conducted the only pilot RCT of a CBT-based intervention (clinicaltrials.gov NCT04199884). In a sample of 84 participants with elevated intolerance of uncertainty during their screening appointment, we compared a researcher-facilitated Intolerance of Uncertainty Treatment (IUT) to a time-matched healthy living control condition. IUT contains psychoeducation, challenging negative automatic thoughts regarding uncertainty through "mythbusting" exercises, and designing behavioral experiments to challenge these negative automatic thoughts. In this study, significant, medium effect size differences (d = .46) emerged between IUT and the control condition, but not until the month 1 follow-up. In addition, reductions in intolerance of uncertainty served as indirect effects from treatment condition to anxiety and depression symptoms. Further, most people found the intervention easy to understand, helpful, and applicable to their daily lives. Building on this prior work, we plan to adapt the existing ultra-brief intolerance of uncertainty intervention to be disseminated via a web-based computerized platform. Given the flexibility afforded via this digital platform, we also propose to include ecological momentary intervention (EMI) to enhance learning through the application of critical interventions skills as needed. EMI is ideal for these brief interventions as it allows for participants to gain the much-needed practice of challenging negative automatic thoughts and completing behavioral experiments critical to internalizing the skills and strategies taught during the intervention. Similar augmentations to brief interventions for stress, generalized anxiety disorder, and panic disorder (d = .5) have been successful in enhancing intervention effects (i.e., an additional d of .4 to .6), further underscoring the promise of including EMI to optimize outcomes.

The goals specific to this project are to 1) engage stakeholders in the design of an ultra-brief intolerance of uncertainty intervention (Enhanced Intolerance of Uncertainty Treatment \[E-IUT\]) and 2) to conduct a pilot trial to evaluate the acceptability, feasibility, and preliminary effect size estimates of E-IUT, in support of a larger fully powered test of E-IUT.