According to research reviewed by Gram, a comprehensive analysis of 183 studies spanning 1980-2024 reveals that people with autism frequently have differences in multiple hormone systems, including stress hormones, growth hormones, sleep hormones, and oxytocin, though these differences don’t directly cause autism but may explain certain symptoms and guide future treatments.
Scientists reviewed 183 studies to understand how hormones might be connected to autism spectrum disorder (ASD). They found that people with autism often have differences in several hormone systems, including stress hormones, growth hormones, and sleep hormones. The research also suggests that exposure to certain chemicals during pregnancy might increase autism risk. While these hormone differences don’t cause autism directly, understanding them could help doctors detect autism earlier and develop new treatments to help people with autism feel better.
Key Statistics
A systematic review of 183 human studies conducted between 1980 and 2024 found that people with autism often have abnormal patterns in stress hormones like cortisol, growth-related hormones called IGF-1, and sleep hormone melatonin.
Research examining data from 183 studies identified connections between autism and exposure to endocrine-disrupting chemicals including phthalates found in plastics and certain pesticides, as well as vitamin D deficiency commonly seen in people with autism.
The comprehensive review found that the social bonding hormone oxytocin often works differently in people with autism, which may relate to social challenges, and thyroid hormones are sometimes imbalanced during pregnancy in mothers who later have children with autism.
The Quick Take
- What they studied: How different hormones and hormone-disrupting chemicals might be connected to autism spectrum disorder
- Who participated: Data from 183 different human studies conducted between 1980 and 2024, involving thousands of people with and without autism
- Key finding: People with autism often have differences in multiple hormone systems, including stress, growth, sleep, and social bonding hormones
- What it means for you: If you or your child has autism, hormone imbalances might explain some symptoms and could be targets for future treatments, though more research is needed
The Research Details
Researchers searched through decades of scientific studies to find patterns in how hormones work differently in people with autism. They looked at studies from major medical databases spanning 44 years of research. This type of review helps scientists see the big picture by combining results from many smaller studies. The researchers focused on human studies only, examining everything from stress hormones to vitamin D levels to chemical exposures during pregnancy.
By combining results from 183 studies, researchers can identify patterns that might not be obvious in smaller individual studies. This approach helps separate real connections from coincidental findings.
This review covers a large number of studies over many decades, published in a respected neuroscience journal. However, the quality depends on the individual studies included, and the researchers acknowledge that proving cause-and-effect is still difficult.
What the Results Show
The review found that people with autism frequently have differences in several hormone systems. Stress hormones like cortisol often follow unusual daily patterns in people with autism. Growth-related hormones called IGF-1 are often at abnormal levels. Sleep hormone melatonin is commonly disrupted, which explains why many people with autism have trouble sleeping. The social bonding hormone oxytocin often works differently, which might relate to social challenges in autism. Thyroid hormones, which affect brain development, are sometimes imbalanced during pregnancy in mothers who later have children with autism.
The research also found connections between autism and exposure to certain chemicals called endocrine disruptors, including phthalates (found in plastics) and some pesticides. Vitamin D deficiency was commonly seen in people with autism. Sex hormones also showed unusual patterns, with some studies suggesting higher levels of certain hormones during fetal development.
This review confirms and expands on previous smaller studies that suggested hormone differences in autism. It’s the first comprehensive look at multiple hormone systems together, showing that autism involves more than just brain differences - the whole body’s hormone system may be affected.
The studies reviewed used different methods and measured different things, making it hard to compare results directly. Most importantly, these studies show associations but can’t prove that hormone differences cause autism - they might be results of autism instead.
The Bottom Line
People with autism may benefit from having their hormone levels checked, especially for sleep, stress, and growth hormones. However, hormone treatments should only be considered under medical supervision as part of comprehensive care.
Families affected by autism, healthcare providers treating people with autism, and pregnant women concerned about environmental exposures should find this research relevant.
This research points toward future treatments rather than immediate solutions. Hormone-based therapies for autism are still experimental and need more testing before becoming standard care.
Frequently Asked Questions
What hormones are different in people with autism?
According to Gram Research analysis of 183 studies, people with autism show differences in stress hormones (cortisol), growth hormones (IGF-1), sleep hormone (melatonin), social bonding hormone (oxytocin), and thyroid hormones. These differences don’t cause autism but may explain certain symptoms.
Can hormone imbalances be treated in autism?
Hormone-based therapies for autism are still experimental and require medical supervision. Checking hormone levels for sleep, stress, and growth hormones may be beneficial, but treatments should only be considered as part of comprehensive care under qualified healthcare provider guidance.
What chemicals during pregnancy might increase autism risk?
Research reviewed by Gram identified endocrine-disrupting chemicals including phthalates (found in plastics) and certain pesticides as potentially connected to autism risk. Reducing exposure to these chemicals during pregnancy and early childhood may be beneficial.
Why do many people with autism have sleep problems?
The review of 183 studies found that sleep hormone melatonin is commonly disrupted in people with autism, which explains why many experience trouble sleeping. This hormone difference is one of several identified in autism spectrum disorder.
Want to Apply This Research?
- Track sleep patterns, stress levels, and mood changes daily to identify patterns that might relate to hormone fluctuations
- Monitor and log exposure to plastics and chemicals, focusing on reducing contact with products containing phthalates during pregnancy or early childhood
- Create long-term tracking of behavioral symptoms alongside potential hormone-related factors like sleep quality, stress events, and seasonal changes that might affect vitamin D levels
This research is for educational purposes only and should not replace professional medical advice. Any hormone-related treatments for autism should only be considered under the guidance of qualified healthcare providers who specialize in autism spectrum disorders.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.