Efficacy of melatonin and ramelteon for the acute and long-term management of insomnia disorder in adults: A systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of placebo-controlled trials
PubMed 37434463 · doi:10.1111/jsr.13939
What was done
A systematic review and meta-analysis following PRISMA criteria was conducted to assess the efficacy of melatonin and ramelteon compared with placebo on sleep quality and quantity in adults with insomnia disorder. The review included 22 studies encompassing 4,875 participants (925 receiving melatonin, 1,804 receiving ramelteon, and 2,297 receiving placebo) evaluating acute and long-term outcomes.
What was found
Compared with placebo, prolonged-release (PR) melatonin significantly improved subjective sleep onset latency (sSOL; weighted difference = -6.30 min, p = 0.031), objective sleep onset latency (oSOL; weighted difference = -5.05 min, p < 0.001), and objective sleep efficiency (oSE; weighted difference = 1.91%, p = 0.043). In patients aged ≥55 years, PR melatonin improved oSE with a weighted difference of 2.95% (p < 0.001). Ramelteon at 4 weeks significantly improved objective total sleep time (oTST; weighted difference = 17.9 min, p = 0.010), subjective total sleep time (sTST; weighted difference = 11.7 min, p = 0.006), sSOL (weighted difference = -8.74 min, p = 0.009), and oSOL (weighted difference = -14 min, p = 0.017). For long-term effects, ramelteon improved oTST (weighted difference = 2.02 min, p < 0.001) and sTST (weighted difference = 14.5 min, p < 0.001).
Why it matters
This review quantifies the sleep improvements offered by melatonin and ramelteon over placebo, demonstrating modest but statistically significant benefits that appear larger in older adults (≥55 years) and with ramelteon.
Limits
The absolute numerical improvements are small (such as ~5–6 minutes reduction in sleep latency with PR melatonin and ~2 minutes long-term gain in oTST with ramelteon). Most melatonin studies only evaluated acute efficacy. The abstract does not report adverse events, safety data, dosage ranges, or study quality assessments.