Autism and Intrusive Sleep

Greetings Earthlings! 🙂

To kickstart 2026, this week I’m going to take a look at the issue of autism and intrusive sleep.

So what exactly is that when it’s at home?

As discussed in my previous post on sleep and autism, 40 to 80% of autists experience issues with sleep. Intrusive sleep (not to be confused with narcolepsy) occurs when you suddenly experience drowsiness or involuntarily lose consciousness, a phenomenon that is usually triggered by boredom/loss of interest in autists with co-morbid ADHD (aka AuDHD). Also known as theta wave intrusion, this phenomenon occurs when slow theta brain waves associated with relaxation, meditation and deep sleep are triggered by a boring task, causing the brain to abruptly disengage, and you to nod off. Essentially these theta waves act as bridges between consciousness and wakefulness.

So many college lectures drifting in and out of consciousness are starting to make sense!

For much of my adult life I’ve struggled with daytime sleepiness hitting me at the most unfortunate times- in the middle of lectures, in crowded theatres during a musical, and several times throughout the work day, especially when dealing with monotonous tasks. I always thought it was due to a lack of sleep the previous night (and as a night owl admittedly, it often is), but I’ve noticed it happening more and more despite having a decent nights sleep. One minute I’m working away, the next I get the sudden urge to take a nap. Conversely if I’m engaged and stimulated, I could be running on 3 hours of sleep and not feel in the least bit sleepy!

But is there any reason the neurodivergent brain is susceptible to intrusive sleep?

People with autism and ADHD tend to have excess theta waves compared with neurotypicals particularly in the frontal cortex of the brain. Higher levels of theta are associated with lower levels of fast beta brainwaves which are needed for focus and alertness, making neurodivergent brains more prone to intrusive sleep and other sleep disturbances.

So don’t judge me too harshly the next time you see me struggling to stay awake in the middle of the day 🫠

Hope you enjoyed this post dear Earthlings! 🙂

Have a lovely weekend!

Aoife