One-third of the U.S. population experience anxiety disorders in their lifetime and only 25% of them seek treatment, reporting logistics and cost of treatment among the primary barriers. A potential way to prevent and treat multiple anxiety disorders is to target the risk factors that contribute to their etiology. One such well-researched risk factor is anxiety sensitivity (AS), a fear of anxiety-related sensations. Given a need for affordable and accessible brief treatments, we and our colleagues have been iteratively developing Brief Enhanced Anxiety Sensitivity Treatment (BEAST), a one-session virtual treatment targeting AS. Older versions of BEAST include psychoeducation, interoceptive exposure (IE), and IE homework. Several studies showed that the previous versions of BEAST reduced AS and, through the reductions in AS, they also reduced anxiety. However, the effect sizes for the decrease in anxiety were modest. Efficacy and personalization may be improved using Ecological Momentary Intervention (EMI). EMI delivers brief interventions remotely in real-time and in natural settings. The goal of the current study is to test the efficacy of adding EMI to BEAST. Participants will be randomly assigned to EMI and control (no EMI) conditions. All participants will receive a virtual 1.5-hour-long intervention group session facilitated by a therapist. The EMI group will receive individualized intervention messages helping them to use new skills for two weeks after the session. After the two-week EMI period, all participants will complete post-treatment measures of AS and anxiety. A month later, they will complete a follow-up assessing AS and anxiety. The efficacy of the EMI component in reducing AS and anxiety will be tested using multilevel modeling. Improving the efficacy of BEAST, while keeping it brief, affordable, and accessible online, is an important step towards making it a treatment that may be used on a large scale.

There is a high need for prevention and treatment of anxiety disorders and for more accessible and affordable treatments. Targeting a risk factor for development and maintenance of multiple anxiety disorders may be an efficient way to prevent and treat anxiety. Anxiety sensitivity (AS)-the fear of anxiety sensations because of the belief that these sensations may lead to catastrophic outcomes-is a potent prevention and treatment target because it predicts development and maintenance of anxiety over time. Anxiety Sensitivity Amelioration Training (ASAT) is an ultra-brief, affordable treatment delivered virtually that targets AS. ASAT is a potent prevention and treatment protocol that reduces anxiety by reducing AS. However, the effect sizes were modest.

Adding Ecological Momentary Intervention (EMI) to the treatment could motivate the participants to apply skills they learned in treatment in a variety of real-life situations and to practice homework exercises. EMI delivers the intervention remotely in real-time and in natural settings, providing better learning through deeper processing. EMI alone is an effective treatment for anxiety and has been an efficacious enhancement to a 6-session treatment for generalized anxiety disorder. However, adding EMI to a 6-session panic disorder treatment did not improve the efficacy of the intervention. Because EMI can reduce anxiety as a stand-alone treatment and due to the inconclusive results about the efficacy of EMI as an added component, it is important to test the effect of adding EMI to the ASAT. We called the treatment including EMI the Brief Enhanced Anxiety Sensitivity Treatment (BEAST).

The goal of this study is to compare the efficacy of the BEAST with and without the EMI component. Interventions will be delivered to the adult community members and students in Athens, Ohio. Based on the power analysis, 75 adult participants will be recruited using email and online advertising. Based on methods used in the prior studies and the current design, inclusion criteria are elevated AS symptoms, access to a smartphone with internet connection. Exclusion criteria are heart disease, respiratory disorders, renal disease, seizure disorder, uncontrolled hypertension or migraines, current substance use disorder (severe), uncontrolled manic or psychotic symptoms, and suicidal ideation that requires hospitalization. All participants will receive a one-hour manualized group intervention educating about anxiety as an alarm system, the benign nature of anxiety sensations, myth-busting, and modifying biases about feared stimuli. The session will also include therapist-guided interoceptive exposure. Participants will be asked to do the exposure at home at least once a day for two weeks. For two weeks after the session, four times a day, the EMI group will receive prompts via the HIPAA-compliant EMI application (metricwire.com). The prompts will ask them about their current anxiety level. If they endorse elevated anxiety, they will be provided with a brief message reminding them about the coping skills covered during the session. They will also receive daily prompts to do exposures and enter the results in the app. The control group will not receive the EMI prompts and will be offered to complete EMI four weeks after the treatment. The intervention will be delivered by graduate students in a clinical Ph.D. program using Microsoft Teams, in groups of 4-6 participants.

AS and anxiety will be assessed using online questionnaires at baseline, at week two and week six after the delivery of the intervention session. Brief interview will be administered at baseline to assess the pathology listed in the exclusion criteria. Multilevel modeling will be used compare AS and anxiety between the groups at both follow-ups controlling for the baseline AS and anxiety. BEAST is an affordable intervention that can be used for prevention and treatment of anxiety and can be administered virtually. This is the first study testing the efficacy an added EMI component to a one-session-long anxiety intervention.

Inclusion Criteria:

• elevated anxiety sensitivity symptoms (i.e., ASI-3 scores greater than or equal to 17),
• have access to a device smartphone with internet connection.

Exclusion Criteria:

• cardiovascular disease or stroke
• respiratory disorders (asthma, COPD, other),
• renal disease,
• epilepsy or other seizure disorder,
• and uncontrolled hypertension or migraines.
• current substance use disorder (severe),
• uncontrolled manic symptoms,
• uncontrolled psychotic symptoms,
• suicidal ideation that requires hospitalization,
• if the participants endorse that English is not their first language in the screening questionnaire and demonstrate significant impairment in understanding the interviewer, they will be considered not proficient in English and will be excluded from the study.

During the consent process, participants are provided information that some of them may receive additional phone app intervention. This is not stressed at any other time during the study. After randomization has been completed, treatment session groups will be formed including participants from both conditions. After the the session, participants receive an email reminding them about the surveys and reminders they will be getting through the app during the upcoming 2 weeks.