Randomized Controlled Trial on the Treatment Effects of Melatonin and Light Therapy on Delayed Sleep Phase Syndrome

Overview

In this study the investigators will examine the effects of melatonin and light therapy on delayed sleep phase syndrome in adolescents 16 up to 20 years old. 60 subjects will be randomized into four different groups; melatonin + light therapy (N=15), melatonin + placebo light (N=15), placebo + light therapy (N=15) and placebo + placebo light. This is a double-blinded treatment and the participants will receive this treatment for 2 weeks. Then they will be re-randomized into two groups; full treatment with light therapy + melatonin (N=30) and no treatment (N=30) for 3 months unblinded. The investigators will test the subjects pre-treatment, post 2 week treatment and after 3 months.

Delayed sleep phase syndrome (DSPS) is a circadian rhythm sleep disorder where the sleep-wake rhythm is significantly delayed according to the environmental demands. Hence, the symptoms consist of major difficulties falling asleep and problems awakening in due time and patients often experience work- and school related impairments (The International Classification of Sleep Disorders: Diagnostic and Coding manual, 2005). However, correct diagnosis is often not made and the treatment offered is, accordingly, often inadequate. DSPS normally develops in interplay between dysfunctional habits/behaviour and biological vulnerability. Bright light therapy and administration of exogenous melatonin comprise the most common interventions. Timed bright light has been shown to effectively phase advance the rhythm (Rosenthal et al., 1990), but no standardized guidelines regarding the duration, intensity or timing of light exposure have been established. Compliance to the treatment is often poor because it involves structuring the daily schedule, which may be hard for the relevant age group. Similarly, administration of melatonin in the evening has been shown to phase advance the rhythm (Lewy et al., 1998; Mundey, Benloucif, Harsanyi, Dubocovich, \& Zee, 2005), but a standardized approach for dose, duration and timing is lacking. It is important to establish effective treatment guidelines for delayed sleep phase syndrome. Large scale studies on the effects of melatonin and bright light treatment in randomized placebo-controlled designs are needed. In a clinical trial we aim to investigate the efficacy of bright light and melatonin treatment using a 4 armed randomized placebo controlled design.