The Sleep Clinic Outcome and Practice Study

1. The effect of light exposure follows a phase-response curve where circadian phase advancement is strongest in the biological morning, whereas light in the biological evening/night may lead to a phase delay. Light therapy is provided by 30 min light exposure using 10 000 lux light boxes. 2. Melatonin 3 milligram is prescribed in tablet forms (not depot), usually 12 hours before the planned rise time. 3. Additionally, blue-light-blocking glasses are used to block light exposure at night, which has been found to advance circadian rhythms. Patients are advised to wear their blue-blocking glasses 12 hours before rise time. Which chronotherapeutic interventions that are used, is considered individually by the clinicians in the Sleep Clinic, but often all three treatment components are used at the same time. Duration of chronotherapy given in the Sleep Clinic vary from 4 to 8 consultations over 1 to 4 months depending on the patients' needs and progress during treatment.

All participants will receive treatment as usual. CBT-I has several components and consists of the following interventions including psychoeducation about sleep: sleep hygiene, sleep restriction therapy, stimulus control, and challenging beliefs and perceptions of sleep. Special emphasis is placed on providing a rationale for behavior change as a primary means of improving sleep as well as addressing dysfunctional beliefs the patients may hold about sleep. During treatment, tapering sleep medication is not necessary. However, if the patients are motivated to do so, this is discussed and a plan for tapering is provided. Treatment duration is typically between 4 to 8 consultations over 1 to 4 months depending on the patients' needs and progress during treatment.