Common reasons ADHD sleep goes sideways
- Sarah Hooper
- May 19
- 3 min read
A second wind at night
A lot of ADHD brains don’t start powering down at “normal” times. If your child looks more alert at 8 to 10 pm, that can be a mix of circadian rhythm differences and nervous system arousal. Sometimes it is also bedtime pressure building all day, then releasing as soon as demands stop.
What helps is not “earlier bedtime” by force. It is usually earlier downshifting, less stimulation, and consistent morning light to anchor the body clock.
Cortisol competing with melatonin production
Melatonin is the hormone that helps the body feel sleepy. Cortisol is a hormone that helps the body feel alert and mobilised. When cortisol is running high in the evening, melatonin tends to be lower or delayed.
In real life this looks like:A child who seems tired after dinner, then suddenly gets wired.Bedtime turns into chatting, bouncing, negotiating, silliness, tears, or sudden hunger.They say they feel tired but cannot switch off.
Common cortisol drivers in the evening can be:Overstimulation, screens, bright light, noisy households, late sport, homework stress, sensory overload, conflict, or a nervous system that has been holding it together all day.
This is why calming routines are more than a “nice” sentiment. They are helping with biochemistry; Lowering arousal helps melatonin do its job.
Low sleep pressure because of late naps or late screen time
Sleep pressure is basically how much the brain has built up the need for sleep across the day. Late naps reduce that pressure. Screens can also delay sleep through two pathways:Light exposure, especially blue light, which tells the brain it is daytime.Dopamine activation, because screens are stimulating and reward based. ADHD brains are often more sensitive to that dopamine hit, so “just one more video” can genuinely keep the brain in gear.
Sensory seeking and restless bodies
Many ADHD kids regulate through movement and input. At bedtime, when they are asked to be still, the body can feel uncomfortable. What looks like “won’t lie down” can be a nervous system trying to find the right level of input.
You might notice:Legs that cannot stop moving. Constant repositioning. Touching, climbing, pressing into you. A need for noise, stories, or repetitive requests.
This is where body based regulation can work better than talking. Think pressure, warmth, stretching, massage, compression, heavy work earlier in the evening, or a predictable sensory wind down.
Anxiety loops, or can’t turn brain off
Bedtime is quiet. Quiet is when some thoughts get loud.
For some kids it is worries. For others it is replaying the day, making plans, scripting conversations, or getting stuck on a topic. ADHD also overlaps with higher rates of anxiety, and the nervous system can sit closer to “on” by default. Practical supports here are usually externalising the brain load. A short bedtime “worry dump” on paper, the same closing script each night, or a predictable check in routine can help the brain stop scanning.
Blood sugar dips overnight
This one gets missed. If dinner is light on protein and fat, or if a child runs on high sugar snacks late afternoon, blood sugar can drop during the night. When blood sugar drops, the body can release stress hormones like adrenaline and cortisol to bring it back up.
That can look like:Waking at 1 to 3 am. Nightmares. Sweaty restless sleep. Waking hungry. Early morning wake ups.
This is one reason I care about protein at dinner, and sometimes a small balanced supper if needed.
Low iron or ferritin, or higher nutrient demand
Iron and ferritin matter for brain function, sleep quality, and sometimes restless legs. Kids can look “wired” at bedtime because their nervous system is under resourced, not because they are choosing chaos.
If restless legs, constant moving, and poor sleep are in the picture, ferritin is one of the things worth checking properly with your GP, alongside the broader clinical picture.
Gut discomfort
Gut pain does not always show up as “my tummy hurts”. It can show up as fidgeting, irritability, refusing to lie down, or waking frequently. Constipation is a classic bedtime saboteur because the gut slows down overnight and discomfort increases when the body is finally still. If a child is regularly constipated, pushing bedtime routines harder rarely works. Fixing bowel function often improves sleep more than any fancy sleep trick.
