All intervention participants will separately complete 6 lessons of Internet based cognitive behavioural therapy (iCBT) about the management of symptoms of depression over 10 weeks. One lesson will be completed every 7 to 14 days (it will become available after the preceding lesson has been completed, with a minimum of 7 days between lessons and a maximum of 14 days). Each lesson will take about 15 minutes to complete. Participants will have access to summaries of each lesson, homework exercises