Recently I was invited to the ABC studios in Brisbane to talk about sleep, in particular; naps. The segment is called Focus (with Emma Griffiths) and allows for some discussion between the host and her guests, then calls are fielded from listeners. One particular listener called to ask about the long term effects of taking melatonin. Her child, who has a high functioning form of autism is taking melatonin currently. Admittedly I didn’t know the answer, my understanding of melatonin use is limited to its short term use for treating insomnia driven from environmental causes such as jet lag and shift work. I promised to look into this for the caller, and post my findings on our website…
Here is what I found:
What does it do?
Melatonin helps to regulate the day/night cycle, or circadian rhythm. The level of melatonin naturally increases in the evening, and is thought to play a role in sleepiness, sleep initiation and sleep maintenance. Interestingly, the nobel prize for medicine went to researchers in the field of circadian rhythms, or body clock. See here for more information on this: http://thoracicandsleep.com.au/medical-newsletter/and-the-nobel-prize-goes-to-sleep/
How can it be used?
Taking melatonin can help to shorten the amount of time taken to fall asleep. Melatonin also seems to improve the quality of sleep in some patient groups (inc the amounts of REM sleep seen and reduces the likelihood of waking or arousing from sleep), and it increases the overall duration of sleep. It may not work for everyone though.
Who may benefit?
The groups who may benefit from melatonin include, but are certainly not limited to:
- Shift work disorder (i.e. going onto or coming off from night shift)
- Jet lag
- Children with developmental/intellectual disorders (inc autism and other central nervous system disorders)
- Elderly persons with sleep/wake disorders (i.e. sundowning, dementia)
Can it be used long term?
Sadly the high level evidence needed to answer this question is just not there, that I could find anyway. Some pharmacological guidelines exist, but I couldn’t find any strong recommendations for or against the long term use of melatonin.
It seems as though melatonin can be used reasonably safely for up to 2 years. It may be safe to use for longer than this, and it may not be safe to use for this long. Thankfully you are unlikely to become addicted to melatonin, or experience a medication induced hangover after taking it. It may however interfere on normal melatonin production within the body.
The benefits/risks of taking melatonin need to be carefully evaluated. Melatonin does impact on other hormones in the body, and as such may cause developmental issues in children and adolescents, over the short or long term.
Some sources state that melatonin, as a medication, is likely to continue its efficacy over time, i.e. the dosage may not need to be increased with prolonged use. However some literature does suggest the effectiveness of melatonin does decrease over time. Neither of these sources were particularly high level evidence.
So I must apologise to the listener, I don’t have a definitive answer for you. I honestly wish you all the best, and hope the small amount of information I have for you is in some small way helpful.
Warning to others:
Do not operate heavy machinery (or drive) within 5 hrs of taking melatonin, or other sleep promoting medication for that matter.
References:
- https://www.sleephealthfoundation.org.au/pdfs/melatonin.pdf
- https://watermark.silverchair.com/sleep-33-12-1605.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAccwggHDBgkqhkiG9w0BBwagggG0MIIBsAIBADCCAakGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMpb9mug4VQhYXFu8CAgEQgIIBek7-JIRKdP5qROgKx7Jl7NR2ltHDsJbJGdV-l-Q4OjRJiX9Zqt0EZMuDkpgGwo1Gd6QaPJSydyZvf1IRX6dJNN9HFXMdP020Zu3vKq9KcsEyRXzu_wwofKbPQnZcAQykeZKeinqjG2aFVGK2mtmqgMeE1cFOHNgzL-5REza0MacBwo7p45nuIXXZpd71nKXxeWu0a4BoH1XlAn4y_CtGRsHZwHI59xA49xdKHsMuGN4ZvzFQBY2vTVi2_SncYjvTsKkuERXvCJeZXFd8yiJKvRj87hndRuVqbnbMAE2A0OnRimM8xhAjldv4xbMUmeWZZDjw6FIrn10bUOsPHHhnMRccTr7tm0yXOKnWyVSZNq514g_PQI6X96oJVUPh86YYJNd3E0jI9A7r0HoBfan0paiAuFzryQOGRuepV8mhREknWMW_DERtkxyrKSX9sCO2FEY7mFEnfgn6nb4o7Q9u6z-UKyVU923N5t2gMQNAYLhNq4D_iJakUwt-Bg
- https://www.ncbi.nlm.nih.gov/pubmed/2151834
- http://jcsm.aasm.org/ViewAbstract.aspx?pid=30219
- http://jcsm.aasm.org/ViewAbstract.aspx?pid=30954
- http://jcsm.aasm.org/ViewAbstract.aspx?pid=26297
- https://www.ncbi.nlm.nih.gov/pubmed/16423108
- https://www.ncbi.nlm.nih.gov/pubmed/23432361
- https://www.webmd.com/vitamins/ai/ingredientmono-940/melatonin
