Melatonin for sleep disorders

Ferracioli-Oda, E., Qawasmi, A.

Published in PLoS One

Abstract

Meta-analysis of melatonin effectiveness for sleep disorders

Methodology

Meta-analysis of 19 randomized controlled trials examining melatonin effects on sleep quality and duration in adults with insomnia. Analyzed sleep onset latency, total sleep time, sleep efficiency, and sleep quality across various dosing regimens (0.3-10mg). Evaluated both immediate-release and controlled-release formulations.

Key Findings

Melatonin reduced sleep onset latency by average of 7.2 minutes (p<0.001) Increased total sleep time by 8.2 minutes Improved sleep quality scores significantly (p=0.003) No significant improvement in sleep efficiency Lower doses (0.3-2mg) as effective as higher doses (5-10mg) Controlled-release formulations better for sleep maintenance Effects more pronounced in delayed sleep phase syndrome No significant side effects or next-day drowsiness No dependency or tolerance development in short-term studies

Conclusions

Melatonin demonstrates modest but consistent benefits for sleep onset and quality in adults with insomnia. Effects are small but clinically meaningful for many individuals. Lower doses appear as effective as higher doses with better safety profile. Melatonin represents a safe first-line option for insomnia management, particularly for circadian rhythm disorders.

Limitations

Small effect sizes for most outcomes High heterogeneity between studies Most studies relatively short duration (<3 months) Varying definitions of insomnia across studies Different formulations and timing of administration Limited data on long-term safety and efficacy Publication bias possible