Researchers will compare three different groups, with 56 adolescents in each group. The first group will receive iCBT with weekly scheduled feedback. The second group will get iCBT with feedback whenever the adolescents ask for it. The last group will be on a waiting list for 14 weeks, before receiving treatment. conditions: Anxiety Disorders studyType: INTERVENTIONAL phases: NA allocation: RANDOMIZED interventionModel: FACTORIAL interventionModelDescription: The RCT is designed as a superiority RCT with the three conditions 1) iCBT with planned feedback 2) iCBT with on-demand feedback and 3) waitlist control. The allocation ratio is 1:1:1 for each condition. The participants will be stratified by aged into the age groups 12-14 years and 15-17 years respectively to secure an even age distribution across conditions. Additionally upon completing session 8 in the program, participants will be randomized to receive or not receive a booster session 12 weeks after finishing the intervention with an allocation ratio of 1:1. The design of the randomized trial is thus factorial including two factors: type of therapist feedback (factor 1) and booster or no booster (factor 2). Data will be collected with parent and adolescent questionnaires at five time points: pre-treatment, post-treatment and at follow-ups after 3, 6 and 12 months. primaryPurpose: TREATMENT masking: NONE maskingDescription: As the study concerns itself with psychotherapy and examines the difference in therapist support, it is practically impossible to blind participants and clinicians, and thus they are not blinded. The research team is involved in the day-to-day operation of the project, including the screening for suicidality, why blinding of the research team is also practically impossible with the current setup. However the analyzes of the trial results will be pseudo-anonymized, so that only the ID number appears on the data sheet in order to get as close to blinding as possible in relation to the research design. count: 168 type: ESTIMATED name: CoolMinds: Internet-based cognitive behavioral therapy (iCBT) measure: The Youth Online Diagnostic Assessment - Child and Parent Versions measure: Spence Children's Anxiety Scale- Child and Parent Versions measure: Child Anxiety Life Interference Scale- Child and Parent Version measure: The Mood and Feelings Questionnaire- Child and Parent Version measure: Working Alliance Inventory - Short Form measure: Working Alliance Inventory for Online Interventions measure: Children´s Anxiety Scale measure: The Short Mood and Feelings questionnaire measure: EuroQol-5 Dimension Youth measure: Client Satisfaction Questionnaire-8 measure: Systems Usability Scale measure: Negative Effects Questionnaire measure: Sociodemographic measures measure: Engagement measure: Cost-effectiveness measure: Cost-effectiveness measure: The Anxiety Disorders Interview Schedule for Children sex: ALL minimumAge: 12 Years maximumAge: 17 Years stdAges: CHILD facility: Centre for Digital Psychiatry status: RECRUITING city: Odense state: Region Of Southern Denmark zip: 5000 country: Denmark name: Helene Skaarnes, MSc (psych)) role: CONTACT phone: +4529649702 email: helene.skaarnes@rsyd.dk name: Kim Mathiasen, Ph.d. role: CONTACT phone: +4561677747 email: kmathiasen@health.sdu.dk lat: 55.39594 lon: 10.38831 hasResults: False