Internet-based cognitive behavioral intervention for adolescents with anxiety disorders: a study protocol for a parallel three armed randomized controlled trial.

Background: Anxiety disorders are among the most prevalent mental health concerns affecting children and adolescents. Despite their high prevalence, statistics indicate that fewer than 25% of individuals in this demographic seek professional assistance for their condition. Consequently, there is a pressing need to develop innovative interventions aimed at improving treatment accessibility.

Objectives: This study aims to assess the effectiveness of Internet-delivered Cognitive Behavioral Therapy (iCBT) for adolescents with anxiety, with a specific emphasis on involving parents in the treatment process.

Methods: The study is structured as a parallel three-armed randomized controlled trial, comparing Internet-delivered Cognitive Behavioral Therapy (iCBT) with planned feedback, iCBT with on-demand feedback, and a waitlist control group, each group including 56 participants. Participants in the two iCBT conditions will undergo a 14-week treatment regimen, while those in the waitlist control group will wait for 14 weeks before starting iCBT with planned feedback. Additionally, participants in the iCBT groups will be randomly assigned to receive a booster session or not. The study design is factorial including two factors: type of therapist feedback (factor 1) and booster or no booster (factor 2). The study population comprises adolescents aged between 12 and 17 years, residing in Denmark, diagnosed with an anxiety disorder according to DSM-5 criteria. The primary outcome measures are the Youth Online Diagnostic Assessment and the Spence Children's Anxiety Scale. Assessments will occur at baseline, post-treatment, and at 3-, 6-, and 12-month follow-ups post-treatment.

Discussion: The findings of this study are anticipated to contribute to improving the accessibility of evidence-based treatments for adolescents with anxiety.

Trial Registration: The study is registered at clinicalTrials.gov, under protocol ID 22/59602. The Initial release was the 16.10.2023, first posted due to technical problems 16.04.2024. https://clinicaltrials.gov/study/NCT06368557?locStr=Odense,%20Denmark&country=Denmark&city=Odense&page=2&rank=13 .