Delayed sleep phase syndrome response to melatonin

Area of Science:

• Chronobiology
• Sleep Medicine

Background:

• Delayed sleep phase syndrome (DSPS) is a circadian rhythm disorder characterized by a persistent difficulty in falling asleep and waking up at conventional times.
• Melatonin, a hormone regulating the sleep-wake cycle, has been explored for its therapeutic potential in circadian rhythm disorders.

Purpose of the Study:

• To investigate the effects of melatonin on the sleep-wake cycle in subjects diagnosed with delayed sleep phase syndrome.
• To determine if melatonin administration can advance sleep onset and wake times in DSPS patients.

Main Methods:

• A randomized, double-blind, placebo-controlled trial was conducted involving 8 subjects with DSPS.
• Subjects received either melatonin (5 mg daily) or a placebo for 4 weeks, with a 1-week washout period.
• Melatonin or placebo was administered at 2200 h, 5 hours before the subjects' habitual sleep onset time.

Main Results:

• Melatonin treatment resulted in a significant advancement of both sleep onset time (mean advance 82 minutes) and wake time (mean advance 117 minutes) compared to placebo (p < 0.01).
• Mean total sleep time was slightly reduced during melatonin treatment (8 h 12 min) compared to placebo (8 h 46 min).
• The alertness acrophase, an indicator of the timing of peak alertness, remained unchanged by melatonin treatment.

Conclusions:

• Melatonin administration effectively advances sleep and wake times in individuals suffering from delayed sleep phase syndrome.
• The findings support the role of melatonin as a phase-setting agent for the sleep-wake cycle in DSPS.
• While melatonin advances sleep timing, its effect on total sleep duration and alertness timing warrants further investigation.