Optimizing Duration of Therapist-guided Internet-delivered Cognitive Behaviour Therapy

All clients will receive the Wellbeing Course developed at Macquarie University, Australia. The Wellbeing Course is a transdiagnostic Internet-delivered cognitive behaviour intervention targeting symptoms of depressive and anxiety disorders. It comprises 5 online lessons targeting: 1) symptom identification and the cognitive behavioural model; 2) thought monitoring and challenging; 3) de-arousal strategies and pleasant activity scheduling; 4) graduated exposure; and 5) relapse prevention. Materials are presented in a didactic (i.e., text-based with visual images) and case-enhanced learning format (i.e., educational stories demonstrate the application of skills) and include homework activities. Lessons are released gradually in a standardized order over 8 weeks. Phone calls will only be made if there is a significant clinical issue requiring therapist attention that cannot be addressed over email (e.g., sudden increase in symptoms). Therapists will spend \~15 mins. per week/per client.