Group bright light therapy compared to treatment as usual for delayed sleep-wake phase disorder among patients in psychiatric care (the SIP trials): a protocol for a pragmatic, randomised controlled trial.

introductionCircadian rhythm sleep-wake disturbances appear to be prevalent in psychiatric populations and may maintain and exacerbate psychiatric symptoms. Bright light therapy (BLT) is, in addition to exogenous melatonin, the treatment of choice for circadian rhythm disorders like delayed sleep-wake phase disorder (DSWPD) and has yielded promising results in patients with comorbid psychiatric illness. However, such patients are rarely offered this treatment in outpatient clinics. The aim of this randomised controlled trial is to investigate whether group BLT for psychiatric outpatients is superior to treatment as usual (TAU). METHODS AND ANALYSIS: 60 patients with moderate-to-severe psychiatric illness who meet the criteria for DSWPD will be recruited from an outpatient psychiatric clinic in Norway. They will be randomised (1:1) to a group-based Sleep School Wake Up! For Circadian (SSWU-C) programme conjointly with TAU or to TAU while on a wait list for SSWU-C. The SSWU-C will be delivered over four biweekly sessions, each lasting 120 min; hence treatment will last 6 weeks. Assessments will be collected at baseline (T1) and after the intervention (T2). The primary outcome will be changes in sleep timing using measures such as sleep diaries, actigraphy and dim light melatonin onset (DLMO) at 6 weeks postintervention. Secondary outcomes include changes in other sleep metrics, symptoms of depression, anxiety, fatigue, problems with work and social adjustment and well-being. Mixed models will be used for data analyses. ETHICS AND DISSEMINATION: Ethical approval was granted in 2020 by the Regional Ethics Committee in Western Norway (REK 2020/66304). Findings will be published in peer-reviewed journals and be presented at research conferences and in relevant media. The results may document the need for more specific sleep-directed treatments in psychiatric clinics as a way of treating not only circadian rhythm sleep-wake disorders but also as a treatment to alleviate psychiatric symptoms. TRIAL REGISTRATION NUMBER: NCT05177055.