Whīria moe: a pilot trial of the Sleep Ninja CBT-I app for adolescents in Aotearoa, New Zealand

Objective Digital sleep interventions offer scalable early mental health support for youth. This study evaluated the feasibility and preliminary impact of Sleep Ninja, a self-guided Cognitive Behavioural Therapy for Insomnia (CBT-I) app, on insomnia and depression symptoms among adolescents in Aotearoa, New Zealand. Method Participants aged 16–18 ( n = 47, 11% Māori, n = 5) with a self-reported desire to improve sleep were recruited via social media and snowball sampling. Users engaged with the app for 30 days. Online assessments of insomnia, depression, and well-being occurred at baseline, post-intervention (30 days), and follow-up (90 days). App acceptability and feasibility were explored via the User Version of the Mobile Application Rating Scale (uMARS) and qualitative interviews ( n = 7). Results Quantitative results showed high app acceptability (uMARS) and feasibility, with participants engaging for an average of 17 days. Significant improvements in insomnia and depression symptoms and well-being were observed at 30 days, with some effects sustained at 90 days. Qualitative interviews further supported acceptability; participants emphasised the importance of cultural relevance and suggested incorporating Te Reo Māori to enhance engagement. Conclusions Sleep Ninja is acceptable to adolescents in Aotearoa, New Zealand. Preliminary results suggest improvements in insomnia, depression, and well-being, supporting further evaluation in a larger trial.