Behavioural and Cognitive Changes During Self-Guided Internet-Delivered Cognitive-Behavioural Therapy for Anxiety and Depression: A Randomised Controlled Trial

Participants will be randomly allocated to either an active internet-delivered cognitive-behavioural therapy (iCBT) treatment group, or to a wait-list control group, who will receive the same iCBT treatment when the active treatment group has finished. The iCBT treatment course, The Wellbeing Course, is a 5-lesson program focusing on the management of anxiety and depression. All 5 Lessons will be administered online (via the internet); each lesson will be completed every 7 to 10 days. Each lesson will take about 15 minutes to complete. Participants will also have access to summaries of each lesson, and will read anonymous stories about other people with depression and anxiety, taking a further 20 minutes per summary. All participants will also receive weekly reminder emails informing them when lessons become available. The duration of the reminder emails will take an additional 2 minutes to access and read. The duration of the program is 8 weeks. Study questionnaires will be administered at application, pre-treatment, during the treatment, post-treatment, and 3 months post-treatment. These questionnaires at application, pre-treatment, post-treatment and 3-months follow up will take about 10-15 minutes to complete. The questionnaires administered during the treatment will take approximately 3 minutes to complete. The software presenting the iCBT treatment course will also record information to inform adherence to the intervention (e.g. lessons completed, download history of other treatment materials in the course, number of logins, and duration of logins)