Melatonin Changes in Dementia
Melatonin is a hormone made by the pineal gland in the brain. It helps control sleep and wake cycles. In healthy people, melatonin levels rise at night to promote sleep and drop during the day. But in dementia, especially Alzheimer’s disease, these patterns change a lot.
People with Alzheimer’s often have lower melatonin levels at night. Their blood and spinal fluid show less melatonin than normal. The peak time for melatonin release also shifts. It might happen too early or too late in the day. This leads to phase misalignment, where the body’s clock gets out of sync.
Studies show that the main sleep-promoting part of melatonin, called 6-sulfatoxymelatonin, is reduced over 24 hours in Alzheimer’s patients. The difference between day and night levels flattens out. This makes sleep fragmented and worsens problems like sundowning, where confusion increases at dusk.
These changes happen because of damage in the brain’s master clock, the suprachiasmatic nucleus. Proteins like beta-amyloid and tau build up and harm cells there. Inflammation adds to the problem. About 25 to 60 percent of Alzheimer’s patients have these rhythm issues. Over 80 percent of those over 65 show big disruptions.
Lower melatonin harms the brain more. It makes it harder to clear toxic proteins, speeding up dementia. Aging alone cuts melatonin production, but dementia makes it worse.
Some research looks at melatonin supplements to help. They might slow memory loss and protect brain cells. But caution is key. People with dementia process melatonin slowly. This can cause daytime sleepiness and raise fall risks, especially in moderate or severe cases. Experts do not recommend it as a long-term fix for chronic sleep problems in dementia.
Exercise may help fix these disruptions naturally. It supports clock genes and boosts melatonin rhythms.
Sources
https://pmc.ncbi.nlm.nih.gov/articles/PMC12738941/
https://hcasouthatlantic.com/blog/entry/4-reasons-to-be-cautious-about-melatonin
https://www.thailandmedical.news/news/melatonin-emerges-as-a-surprise-weapon-against-alzheimer-s-disease
https://www.neurology.org/doi/10.1212/WNL.0000000000214513
https://primaryimmune.org/about?id=c_say-goodbye-to-sleepless-nights-dnutrixn-advance-melatonin-10mg-sleep-gummies-blueberry-flavour
