Effect of a smartphone app, Sleep Ninja, on insomnia, sleep and depression in young people experiencing insomnia and depression symptoms

Sleep Ninja Sleep Ninja is a smartphone app that delivers CBT-I in an accessible, relevant way for young people. It was developed by the Black Dog Institute and includes the core CBT-I approaches: psychoeducation, sleep scheduling, stimulus control, sleep-focused cognitive therapy, sleep hygiene and behavioural activation. Users communicate with the Sleep Ninja, a sleep coach, via a forced-choice text messaging platform. The app is based on gaming principles and users progress through six levels of ‘belts’, starting with a white belt and working their way to black belt status. To obtain each belt, users must complete one ‘training session’ (module), which takes about 5 minutes, and log three nights (within 7 days) of sleep tracking within the app’s sleep diary. When they have completed each belt, they receive feedback on their sleep and specific advice if they indicate that their wake-up time varies by more than 2 hours from the previous day or if they log that they had less than 6 hours of sleep. Optional features include access to a meditation recording, extra sleep information, sleep tips, and ‘get help now’ that links directly to New Zealand crisis support services and helplines. If participants agree, the app sends reminder notifications to enter sleep diaries, begin winding down for sleep, complete training sessions, and return after periods of inactivity. The standard duration of the intervention is 6 weeks (one week per belt level), though because of the 3 sleep logs per level, it can be completed in a minimum of 18 days. The active study period tracks participants over 30 days.