Sleep onset latency

Method

Interval from lights-out to the first epoch of persistent sleep, by polysomnography, actigraphy or sleep diary, with the instrument recorded on the edge.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

The endpoint melatonin trials most consistently move, and the one where instrument choice changes the answer most: diary-reported latency runs longer than polysomnographic latency in the same night, and actigraphy cannot see wakeful stillness at all. Separate from total sleep time, which can stay flat while this falls.

Findings

2 findings from 1 compound, strongest first.

• melatonin — decreases

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.Findingreplicated ×1

  “The pooled SMD in healthy subjects showed that exogenous melatonin significantly decreased SOL compared to placebo.”

  Study

  meta-analysis

  Population

  Healthy adult participants; pooled RCTs of exogenous melatonin vs placebo, sleep onset latency by polysomnography or actigraphy

  Melatonergic agents influence the sleep-wake and circadian rhythms in healthy and psychiatric participants: a systematic review and meta-analysis of randomized controlled trials.2022PMID:35115662

• melatonin — decreases

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.Findingreplicated ×1

  “Our meta-analysis demonstrated melatonin had a significant benefit in reducing sleep latency.”

  Study

  meta-analysis

  Population

  Adults and children with primary sleep disorders (insomnia, delayed sleep phase syndrome, REM sleep behaviour disorder) in placebo-controlled trials; primary outcome; fixed-effects pooled estimate, latency measured by polysomnography/actigraphy or by sleep diary depending on trial

  Meta-analysis: melatonin for the treatment of primary sleep disorders.2013PMID:23691095