Why ADHD Brains Struggle with Sleep (And How to Help)

There’s an increasing amount of research showing that ADHD and sleep problems are significantly correlated. In adults with ADHD, up to 80% also have insomnia, with similar rates of up to 82% in children with ADHD.

These studies have found that problems with falling asleep and staying asleep persist in ADHD even after controlling for co-occurring anxiety and depression. Researchers have also found differences in chronotype, melatonin onset, and cortisol levels in those with ADHD.

All of this can make it very difficult for people with ADHD to get the amount of rest they need, which in turn can exacerbate ADHD symptoms and create a hard cycle to break.

In today’s blog we’ll look at some of the reasons ADHD interferes with sleep and a few evidence-based ways to help.

Why

Evidence shows that people with ADHD are more likely to have an evening chronotype, with sleep patterns shifted later by about 90 minutes compared to neurotypical adults.

A study conducted with both adults and children found that those with ADHD have a smaller pineal gland, which is the gland responsible for secreting melatonin. This may contribute to why children with ADHD tend to have melatonin onset delayed by an average of 45 minutes, and adults by an average of about 90 minutes.

Lastly, a meta-analysis found that children with ADHD exhibit lower cortisol levels compared to controls, especially in the morning. Researchers haven’t proven the cause yet, but one theory is that because individuals with ADHD are more prone to being night owls, they may have more nighttime light exposure, which can disrupt the circadian rhythm.

What to do

Melatonin

Since one reason for sleep problems in ADHD is delayed melatonin production, several studies have looked at how melatonin supplementation might affect sleep.

In a randomized trial of adults with ADHD, participants who were given 0.5 mg of melatonin per night released melatonin about 88 minutes earlier and showed a 14% reduction in ADHD symptoms.

In another randomized trial of 101 medication-free children with ADHD and insomnia, researchers found that giving children 3 to 6 mg of melatonin nightly for four weeks moved melatonin release earlier by 44 minutes. Total sleep time also increased by about 20 minutes per night.

These studies on melatonin are promising, but it’s important to remember that melatonin is a powerful hormone. Even though it’s sold over the counter, it’s not well regulated, and it’s always recommended to speak with a doctor before using it.

Bright light therapy

Another intervention that has been studied is bright light therapy.

One study exposed participants to a week of natural light-dark cycles only. These participants began releasing melatonin about 2.6 hours earlier than they had at baseline.

Even larger changes were seen when bright light therapy was combined with melatonin. Adults with ADHD shifted their sleep onset about two hours earlier than baseline.

This may be particularly relevant in the winter, since about 27% of adults with ADHD also experience seasonal affective disorder, with females being at the highest risk.

Exposure to natural light in rhythm with the sun will always be the best and cheapest option. However, if the sun rises too late in your area during certain times of year, a 10,000 lux medical grade light box can be a safe and effective alternative.

Behavioral interventions

Behavioral interventions have also been studied as a way to improve sleep in individuals with ADHD.

In a randomized trial of 244 children with ADHD, a behavioral sleep intervention significantly improved ADHD symptom severity, sleep quality, behavior, functioning, and overall quality of life at a six month follow up.

Although they haven’t been specifically studied in ADHD populations, several behavioral strategies have been shown to benefit people with an evening chronotype, which may also apply to individuals with ADHD who tend to be night owls.

One intervention is exercise, which has been shown to move melatonin onset earlier in people with later chronotypes. Other helpful strategies include waking up two to three hours earlier, waking up at the same time every day, maximizing morning light exposure, avoiding late dinners, avoiding caffeine after 3pm, exercising in the morning, and avoiding late afternoon naps.

One study found that within three weeks, participants who made these behavioral changes released melatonin an average of two hours earlier, woke up 1.9 hours earlier, and had a cortisol peak 2.2 hours earlier. Subjective depression scores also decreased by 58% and stress scores by 40%.

While more studies are needed specifically in ADHD populations, applying interventions that work for individuals with a later chronotype may be an effective and low cost strategy for supporting sleep in people with ADHD.

Final Thoughts

There are both biological and behavioral reasons that people with ADHD are more susceptible to sleep issues, but there are also interventions that can help.

More research is still needed specifically for individuals with ADHD. However, based on the evidence we have right now, melatonin supplementation with guidance from a doctor, bright light therapy, and behavioral strategies such as exercise, consistent wake times, and limiting caffeine can help people with ADHD start to regain some control over their sleep.

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Luu B and Fabiano N (2025) ADHD as a circadian rhythm disorder: evidence and implications for chronotherapy. Front. Psychiatry 16:1697900. doi: 10.3389/fpsyt.2025.1697900