Melatonin Deficiency in ASD

Can This Contribute To Sleeplessness In Your Child?

Nov 5, 2008

A recent research article found that 65% of individuals with ASD have a reduction in melatonin. This is due to a reduced ability to convert serotonin into melatonin.

Melatonin is a hormone found naturally in humans and other organisms that has several biological activities. It has antioxidant and immuno-modulating properties but its most vital role is in regulating circadian rhythms which impact sleeping and feeding patterns. Because melatonin has benefits for sleep, it has become a common dietary supplement in the United States. A study published in 2008 in Molecular Psychiatry found that individuals with autism spectrum disorders (ASD) have lower amounts of melatonin in their blood. The researchers found that this deficit was caused by a reduction in ASMT (acetylserotonin methyltransferase) gene. This gene encodes for the last enzyme in melatonin synthesis from serotonin.

Melatonin Synthesis: From Tryptophan to Serotonin to Melatonin

Melatonin is produced by the pineal gland in the brain as well as in parts of the eye and gastrointestinal tract in four primary steps.

Researchers have discovered that individuals with ASD have significantly higher amounts of serotonin than control individuals. This is due to the reduced ASMT activity that converts serotonin into melatonin. They found reduced plasma melatonin levels in 65% of individuals with ASD.

Does This Cause Autism?

Previously, it was thought that autism was caused by mercury in MMR vaccines, teratogens (known to cause birth defects), or maternal nutritional status. But recent research has started examining genetic causes to the disease. This research paper is one of many examples of genetic variations that can contribute to ASD. The primary investigators found that the reduction in ASMT activity is due to variations in the ASMT gene. They discovered several ASMT variations including a splice-site mutation, four non-synonymous variations and two synonymous variations. All of these variations resulted in less melatonin found in the blood. Without adequate melatonin in the body, individuals can have trouble sleeping, insomnia, irritability, lack of concentration as well as more serious chronic diseases such as breast or prostate cancer.

Melatonin Supplement?

The use of melatonin supplements has grown tremendously with more people having trouble sleeping. Melatonin is available in the United States and Canada without a prescription. It appears to have very little side-effects with short-term use at low doses (up to 3 mg/day) and can be a beneficial natural sleep aid. There have not been any long-term studies completed examining the safety of melatonin so it is not encouraged to use continue melatonin supplementation for more than 3 consecutive months.

Due to a reduction in ASMT activity in some individuals with ASD, the use of a high quality melatonin supplement may help alleviate sleeplessness and chronic insomnia.

Melke, J., et al. Abnormal melatonin synthesis in autism spectrum disorders. Molecular Psychiatry. 13(1): 90-98, 2008.

The copyright of the article Melatonin Deficiency in ASD in Autism Research is owned by Brooks W. Leigh. Permission to republish Melatonin Deficiency in ASD in print or online must be granted by the author in writing.