ADHD’s Silent Partner: The Sleep Hormone Connection

How the sleep hormone could transform ADHD treatment

I’ve been taking a time-release 10 mg tablet of melatonin every night for about three decades (maybe four); I first learned about it when I was doing international relief work and was constantly whacked by jet-lag. The past years since I’ve cut back on international travel, I’ve just been taking it to help get a good night’s sleep.

Little did I know it may have something to do with the reduction of my ADHD “symptoms”; I’d attributed that to aging. But it may not be that simple.

Scientists have just uncovered an intriguing connection between the body's natural sleep hormone and ADHD symptoms in children. A major study from Japan’s Hamamatsu University School of Medicine suggests that the way our bodies produce melatonin — often called the “sleep hormone” — might play a bigger role in ADHD than we previously thought.

Let’s break this down: melatonin is like your body’s internal nighttime signal. When darkness falls, your brain’s pineal gland starts pumping out melatonin, essentially telling your body “Hey, it’s time to wind down.” It’s the conductor of your body’s sleep orchestra, keeping everything on a steady daily rhythm. But for Hunters with ADHD, this nightly routine often goes off track.

As I noted in the latest edition of my book ADHD: A Hunter in a Farmer’s World, there are multiple studies indicating that people diagnosed with ADHD are often twice as likely to also have difficulties falling asleep or staying asleep. My mom used to joke that I almost flunked kindergarten because I couldn’t take a nap; I don’t recall ever having taken a daytime nap in my entire life.

Now comes this research on melatonin that may explain what’s going on.

Dr. Nagahide Takahashi, who led the research at Tokyo’s National Center of Neurology and Psychiatry, was curious about why so many children with ADHD struggle with sleep. “We see sleep problems all the time in kids with ADHD,” he explains, “but nobody really understood why. We wanted to know if there might be a genetic connection between sleep patterns and ADHD symptoms.”

To get to the bottom of this mystery, Takahashi’s team looked at genetic data from more than 30,000 people across different countries. They tracked melatonin production by measuring its byproducts in urine — kind of like following footprints to find where someone’s been. What they found was fascinating: kids whose genes predicted lower melatonin production typically showed more severe ADHD symptoms, especially when it came to paying attention.

But here’s where it gets interesting. You might think the connection would be simple — less melatonin means worse sleep, which leads to more ADHD symptoms, right? Actually, the relationship turned out to be more complicated. The researchers discovered that genes affecting melatonin production seem to influence ADHD symptoms directly, not just through sleep disruption.

They also found something unexpected: a connection to inflammation in the body. The study revealed that a molecule called interleukin-6, which is involved in inflammation, might be the missing link between melatonin and ADHD symptoms. Kids with ADHD often have higher levels of this molecule, and it seems to be connected to both sleep patterns and ADHD behaviors.

What does all this mean for families dealing with ADHD? According to Dr. Takahashi, it reinforces something many parents and doctors already suspected: good sleep habits really matter. “Creating healthy sleep routines could help manage ADHD symptoms,” he says. The research suggests that helping kids maintain regular sleep patterns might do more than just fight fatigue — it could actually help with their ADHD symptoms by affecting the body's internal chemistry.

Looking ahead, researchers want to explore whether treatments focusing on melatonin might help kids with ADHD. This could include anything from melatonin supplements to new ways of supporting the body’s natural sleep-wake cycle. “We’re excited to see how we might use this knowledge to help children with ADHD,” Takahashi adds.

While the study wasn't perfect — they couldn’t directly measure melatonin in the children’s blood, for instance — it’s a big step forward in understanding how ADHD works in the body. It shows that ADHD isn’t just about behavior or brain chemistry; it’s connected to fundamental processes like sleep and inflammation that affect the whole body.

For parents and healthcare providers, the takeaway is clear: paying attention to sleep patterns could be crucial in helping kids with ADHD. Future treatments might take a more comprehensive approach, considering not just behavior and attention, but also sleep patterns and the body's natural rhythms.

The research team is now planning to investigate how they might use this knowledge to develop better treatments. They’re particularly interested in finding ways to help children with ADHD get their sleep patterns back on track, which could make a real difference in managing their symptoms.

“This isn’t just about telling kids to go to bed earlier,” Takahashi notes. “We’re discovering that sleep, ADHD, and the body's internal chemistry are all connected in ways we never realized before. Understanding these connections could lead to better ways to help children with ADHD and their families.”