The goal of this clinical trial is to evaluate a smartphone based just-in-time adaptive intervention (JITAI) tool to deliver somatic behavioral recommendations for anxiety management among youth. The main questions it aims to answer are:

• Is the JITAI tool acceptable among the adolescent study population?
• Is the JITAI tool feasible to deliver to the adolescent study population?
• Does the study support preliminary efficacy of the JITAI tool among the adolescent study population?

The tool will be pilot-tested among a sample of 50 rural adolescents experiencing elevated anxiety levels who will be randomly assigned to the JITAI tool or a waitlist control, for a treatment period of 3 months.

Participants will be asked to:

• Use the smartphone based JITAI tool which will deliver somatic behavioral recommendations intended to manage anxiety levels for a treatment period of 3 months
• Respond to the tool's prompts on a daily basis and follow the delivered behavioral recommendations
• Complete anxiety and interoception assessments at study start, study end (3 months), and one-month follow-up
• Complete usability and user experience instruments at study end (3 months)

It is imperative to improve the inclusive reach of effective anxiety treatments for adolescents. Anxiety disorders are among the most common psychiatric conditions in adolescents yet they are largely undertreated, particularly in rural areas. Behavioral interventions are efficacious in reducing anxiety symptoms while providing individuals with a toolkit of knowledge, skills, and techniques that empower self-care. As anxiety disorders involve an interconnected relationship between psychological and physiological processes, behavioral interventions that combine mind-body practices are coming to be seen as a particularly powerful therapeutic approach. Such treatments can include physical exercises, expressive movements, and other activities that emphasize interoception, autonomic reactivity, and the role of the body in processing and regulating emotions. However, research is needed to tailor these somatic approaches to an adolescent population, more rigorously evaluate their efficacy in diverse settings, and enhance their accessibility in traditionally underserved communities. Further, it is key to ensure such interventions are responsive and available in real-time, considering in-the-moment support is a critical aspect of quality anxiety care. Mobile technology is a promising platform for delivering personalized behavioral interventions at-scale and on-demand, including through emerging designs like just-in-time adaptive intervention(JITAI). This project aims to design, develop, and test a smartphone based JITAI tool to deliver somatic behavioral recommendations to manage anxiety levels. It will use a community-engaged research approach that partners with adolescents. Following qualitative needfinding to understand anxiety experiences and care needs as well as participatory design of the digital intervention, the tool will be pilot tested with a sample of 50 rural adolescents experiencing elevated anxiety levels who will be randomly assigned to the JITAI tool or a waitlist control, for a treatment period of 3 months. Objectives include demonstrating the acceptability, feasibility, and preliminary efficacy of this intervention approach.

Inclusion Criteria:

• Adolescent (age 13-17 years old)
• New Hampshire resident
• Fluency in English
• Able to provide assent
• At least mild (≥5) anxiety based on the GAD-7 assessment

Exclusion Criteria:

• Under 13 years old
• Over 17 years old
• Not a New Hampshire resident
• Unable to provide assent
• Less than mild (<5) anxiety based on the GAD-7 assessment