Is melatonin (melatonin) effective for treating sleep disorders, such as insomnia and jet lag?

Effectiveness of Melatonin for Sleep Disorders

Melatonin is effective for specific sleep disorders, particularly circadian rhythm sleep disorders like jet lag and delayed sleep phase syndrome, but has limited efficacy for primary insomnia in adults.

Effectiveness by Sleep Disorder Type

Circadian Rhythm Sleep Disorders

• Melatonin is highly effective for jet lag, particularly for eastward travel across five or more time zones, with a Number Needed to Treat (NNT) of 2 1
• Melatonin helps regulate circadian rhythms by binding to M1 and M2 receptors, suppressing REM sleep motor tone and normalizing circadian features of sleep 2
• For optimal jet lag management, melatonin should be taken close to target bedtime (10pm-midnight) at the destination 1
• Doses between 0.5-5mg are similarly effective for jet lag, with 5mg providing slightly better sleep quality than lower doses 1

Insomnia in Adults

• The American Academy of Sleep Medicine suggests against using melatonin for treating sleep onset or maintenance insomnia in adults (weak recommendation) 2
• Meta-analyses show melatonin has small effects on sleep latency with little effect on wake after sleep onset (WASO) or total sleep time in adults 2
• The 2017 AASM Clinical Practice Guideline found minimal overall evidence for melatonin's efficacy in improving sleep onset, maintenance, or quality in adults 2
• Studies using 2mg doses in older adults (>55 years) showed improvements that did not reach clinical significance thresholds 2

Insomnia in Children with Autism Spectrum Disorder (ASD)

• Melatonin is effective for improving sleep in children with ASD, particularly for reducing sleep latency and increasing total sleep time 2
• Studies show significant improvements in Children's Sleep Habits Questionnaire (CSHQ) values with melatonin treatment in children with ASD 2
• Sleep latency improved from 42.9 to 21.6 minutes (p<.001) in children with ASD using melatonin 2
• Melatonin is safe and well-tolerated in children with ASD and improves aspects of daytime behavior and parenting stress 2

REM Sleep Behavior Disorder

• The American Academy of Sleep Medicine makes a conditional recommendation for immediate-release melatonin in the treatment of REM sleep behavior disorder 2
• Starting dose is usually 3mg at bedtime, which can be titrated up to 15mg if needed 2
• Melatonin suppresses REM sleep motor tone and normalizes circadian features of REM sleep in patients with RBD 2

Dosing and Administration

• For jet lag: 0.5-5mg taken at destination bedtime (10pm-midnight), with 5mg providing slightly better sleep quality 1
• For REM sleep behavior disorder: 3mg immediate-release at bedtime, titrated up to 15mg if needed 2
• For children with ASD: 1-4mg taken 30-40 minutes before bedtime 2
• Timing is critical: taking melatonin at the wrong time (early in the day) can cause sleepiness and delay adaptation to local time 1

Safety Profile

• Melatonin is generally well-tolerated with few adverse effects in short-term use 3
• Unlike benzodiazepines and z-drugs, melatonin does not cause hangover, withdrawal effects, or addiction 4
• Caution is advised in people with epilepsy due to case reports of adverse effects 5
• Potential interaction with warfarin has been reported 5, 1
• Long-term safety data is limited, and pharmaceutical quality control of melatonin products varies 1

Clinical Application Algorithm

1. Identify the specific sleep disorder:

   • For jet lag: Melatonin is first-line therapy 1
   • For REM sleep behavior disorder: Consider melatonin as one of four recommended agents 2
   • For children with ASD and sleep problems: Melatonin is effective after behavioral interventions 2
   • For primary insomnia in adults: Consider other interventions before melatonin 2

2. Select appropriate dosing based on condition:

   • Jet lag: 0.5-5mg at destination bedtime 1
   • RBD: Start with 3mg, titrate up to 15mg if needed 2
   • Children with ASD: 1-4mg, 30-40 minutes before bedtime 2

3. Monitor effectiveness:

   • For jet lag: Assess adaptation to new time zone 1
   • For chronic conditions: Use sleep diaries, actigraphy, or validated questionnaires 2

4. Consider combination approaches:

   • For jet lag: Combine with light exposure management for optimal results 5
   • For RBD: Consider combination with clonazepam if monotherapy is inadequate 2