Autism and Sleep: Why Can Getting a Good Night's Sleep Be So Difficult?

adminaspect
2 days ago
10 min read

Feeling exhausted but unable to switch off.

Taking hours to fall asleep.

Waking repeatedly throughout the night.

Finding that the smallest noise, light or sensation suddenly becomes impossible to ignore.

For many autistic people, sleep can be complicated.

Research increasingly suggests that sleep difficulties are particularly common among autistic children and adults. These difficulties can range from struggling to fall asleep and waking frequently during the night to irregular sleep patterns and waking much earlier than intended.

But why?

The answer appears to be more complicated than simply needing a better bedtime routine.

Researchers are investigating connections between autism and sensory processing, circadian rhythms, melatonin, anxiety, co-occurring conditions and the body's ability to transition from wakefulness into sleep.

Understanding these connections may help us understand why an autistic person can be completely exhausted — yet still find it incredibly difficult to sleep.

Sleep Difficulties Are Common in Autism

Sleep problems have been recognised in autistic people for many years.

They can include:

difficulty falling asleep
frequent waking during the night
waking very early
difficulty returning to sleep
irregular sleep and wake times
restless or disrupted sleep
reduced overall sleep
difficulty establishing a consistent sleep routine.

Importantly, this doesn't appear to be limited to autistic children.

A systematic review and meta-analysis examining sleep in autistic adults compared both subjective reports and objective measurements, including actigraphy and polysomnography.

Researchers identified differences across numerous measures of sleep.

Compared with non-autistic adults, autistic adults showed poorer sleep efficiency, took longer to fall asleep on objective sleep testing and spent more time awake after initially falling asleep.

In other words, the difference wasn't simply that autistic people felt as though they were sleeping badly.

Differences could also be detected through objective measurements.

Why Might Autism Affect Sleep?

There probably isn't one single explanation.

Autism involves differences in the way the brain processes information, including sensory information and signals from within the body.

Sleep, meanwhile, is controlled by a complicated interaction between our internal body clock, hormones, environment, behaviour, physical health and nervous system.

Several of these systems may work differently in autistic people.

Researchers are therefore investigating multiple possible explanations.

Sensory Processing Doesn't Stop at Bedtime

Imagine trying to sleep while being intensely aware of:

The hum of an appliance.

A clock ticking.

A streetlight coming through the curtains.

The texture of your pyjamas.

A crease in the bedsheet.

Your partner breathing.

The temperature of the room.

A neighbour closing a car door outside.

For somebody else, the brain may gradually filter these sensations into the background.

For an autistic person with heightened sensory sensitivity, that may be much more difficult.

Sensory processing differences are extremely common in autism and can involve sound, light, touch, smell, temperature, movement and internal bodily sensations.

And emerging research suggests that sensory differences and sleep problems may be closely connected.

A 2026 systematic review examined 16 studies investigating sleep and sensory processing in autistic children and adolescents.

The researchers found significant associations between sleep difficulties — particularly insomnia symptoms and waking during the night — and sensory differences, especially sensory sensitivity and sensory avoidance.

Tactile and vestibular sensory processing also appeared particularly relevant.

However, the researchers cautioned that much of the evidence relied on parent-reported questionnaires and that more longitudinal and objective research is needed.

At present, we can say that sensory difficulties and sleep problems frequently occur together.

We cannot yet say with certainty that one directly causes the other.

The Autistic Brain May Find It Difficult to "Switch Off"

Sleep isn't simply the absence of activity.

The brain has to transition from wakefulness into sleep.

For some autistic people, that transition itself may be difficult.

A person may be physically exhausted while their mind remains extremely active.

Thoughts may continue looping.

Conversations from earlier in the day may be replayed.

An unfinished task might feel impossible to put aside.

A special interest may occupy the person's attention.

Tomorrow's plans may be mentally rehearsed repeatedly.

An unexpected event that occurred earlier may still be being processed.

This can sometimes overlap with anxiety, ADHD, perseverative thinking or a strong need for predictability.

And unfortunately, trying very hard to sleep can sometimes make sleep feel even further away.

Circadian Rhythms and the Body Clock

Our bodies operate according to an approximately 24-hour internal clock known as the circadian rhythm.

This system helps regulate when we feel awake and when we begin to feel sleepy.

Light entering the eyes provides one of the most important signals to this internal clock.

As evening approaches and light levels decrease, the body normally begins preparing for sleep.

One hormone involved in this process is melatonin.

Melatonin is produced primarily at night and helps signal to the body that it is time for sleep.

Researchers have investigated whether differences in circadian regulation and melatonin production may contribute to sleep difficulties in some autistic people.

This does not mean that every autistic person has a "melatonin deficiency".

The biology is considerably more complicated than that.

However, differences involving melatonin production, timing and circadian rhythms have been proposed as one possible contributor to sleep disturbance in autism.

This may also help explain why melatonin has become one of the most extensively studied treatments for sleep difficulties in autistic children.

What Does the Research Say About Melatonin?

Melatonin has been studied considerably more than many other sleep interventions in autism.

A 2023 systematic review and meta-analysis examined 15 eligible studies investigating melatonin for sleep problems in autistic people.

Overall, melatonin was associated with improvements in:

total sleep time
the amount of time it took to fall asleep
sleep efficiency.

The researchers did not find a statistically significant overall improvement in every measure, including waking after sleep onset and night-time awakenings.

Another 2023 meta-analysis specifically examining autistic children also found that melatonin shortened the time taken to fall asleep, increased total sleep time and reduced night waking in the studies included.

More recently, a 2025 systematic review and meta-analysis found that melatonin significantly improved sleep quality and total sleep time in autistic children.

So there is genuine evidence that melatonin can be helpful for some autistic people.

However, it is not necessarily the answer for everyone.

Sleep difficulties can have many causes, and treating a sensory, behavioural, environmental or medical sleep problem purely as a melatonin problem may overlook what is actually keeping the person awake.

In the UK, NICE recommends first assessing the nature of an autistic child or young person's sleep problem and developing an individualised sleep plan. Medication is considered when sleep difficulties persist despite this and are having a significant negative impact.

Sometimes the Environment Is the Problem

This is particularly important when thinking about autistic children.

A conventional sleep recommendation might say:

"Make the bedroom calm and comfortable."

But what exactly does comfortable mean to that particular autistic person?

A bedroom that appears perfectly comfortable to a parent may contain numerous sources of sensory discomfort for an autistic child.

Perhaps the room is too warm.

Perhaps the bedding feels uncomfortable.

Perhaps the hallway light shines underneath the door.

Perhaps there is an electrical noise nobody else notices.

Perhaps total darkness is frightening.

Perhaps silence itself feels uncomfortable and predictable background noise is actually calming.

This is why autism-friendly sleep support needs to be individualised rather than simply prescriptive.

The goal isn't necessarily to create the bedroom that somebody else considers ideal.

It's to create an environment in which that particular nervous system feels able to settle.

Routine Can Be Both Helpful and Complicated

Predictability can be extremely regulating for many autistic people.

A consistent sequence before bed can therefore help the brain recognise that the day is ending.

For example:

bath or shower → pyjamas → preferred drink → quiet activity → bed.

Repeating the same sequence can reduce uncertainty and make the transition towards sleep more predictable.

However, routines can also become extremely specific.

An autistic child may become accustomed to sleeping only when particular conditions are present.

A specific parent may need to be nearby.

A particular object may need to be positioned correctly.

A certain programme may need to be playing.

The sequence may need to happen in exactly the expected order.

If something changes — perhaps during a holiday, hospital stay, house move or even because a favourite item is unavailable — sleep can become considerably more difficult.

Understanding this as a need for predictability rather than simply "difficult behaviour" can completely change how adults respond.

ADHD Can Complicate the Picture

Autism and ADHD commonly co-occur.

For autistic people who also have ADHD, sleep may become even more complicated.

ADHD itself is associated with sleep difficulties and differences in circadian rhythms.

Someone may be physically tired but mentally stimulated.

They may lose track of time during an activity and suddenly realise it is 2am.

They may struggle to disengage from something interesting.

They may need stimulation to regulate themselves but simultaneously require reduced stimulation to fall asleep.

This can create a frustrating situation where the person desperately wants to sleep but their brain appears to have other plans.

Anxiety Can Follow Us Into Bed

Anxiety is also common among autistic people.

Bedtime removes many of the distractions that occupy us throughout the day.

Suddenly there is space to think.

For someone who has spent the day navigating social situations, sensory environments, uncertainty or masking, those thoughts may arrive all at once.

Did I say something wrong?

What is happening tomorrow?

What if something changes?

Why did that person respond like that?

What if I can't sleep?

And once someone becomes anxious about sleep itself, another cycle can develop.

They worry that they won't sleep.

That worry makes them more alert.

Being more alert makes sleep harder.

Not sleeping confirms the worry.

And the cycle continues.

Physical Health Shouldn't Be Forgotten

Not every sleep problem experienced by an autistic person is caused by autism.

This is extremely important.

Someone may be waking because they are experiencing:

pain
reflux
gastrointestinal discomfort
restless legs
breathing difficulties
medication effects
seizures
another sleep disorder.

Obstructive sleep apnoea, for example, can cause disrupted sleep and repeated waking.

NICE specifically recommends specialist assessment when an autistic child or young person snores loudly, chokes or appears to stop breathing while asleep.

Just as we discussed in our article on autism and chronic pain, physical symptoms should not automatically be attributed to autism.

Autistic people can develop the same medical conditions as everybody else.

Poor Sleep Can Make Everything Else Harder

The relationship between autism and sleep can also work in the opposite direction.

Autism may contribute to sleep difficulties, but poor sleep can make everyday autistic challenges much harder to manage.

After a poor night's sleep, sensory tolerance may be reduced.

Sounds may feel louder.

Lights may feel brighter.

Small frustrations may become harder to manage.

Executive functioning may become more difficult.

Communication may require more effort.

Social interaction may feel exhausting.

The person may have less capacity to cope with unexpected changes.

For some autistic people, this can mean increased distress, shutdowns, meltdowns or a much greater need for recovery time.

This doesn't necessarily mean that their autism has suddenly become "more severe".

Their nervous system may simply have considerably fewer resources available after inadequate sleep.

Supporting Better Sleep

There isn't one autism sleep routine that will work for everybody.

Instead, it can be useful to investigate why sleep is difficult for that particular person.

Questions might include:

Is the bedroom sensory environment comfortable?
Is the person actually sleepy at the expected bedtime?
Is there a predictable transition into sleep?
Are anxiety or repetitive thoughts keeping them awake?
Is ADHD contributing?
Are they experiencing pain or gastrointestinal discomfort?
Are they waking frequently?
Are there signs of breathing difficulties or another sleep disorder?
Does their sleep pattern change depending on stress, routine or sensory demands?

Keeping a sleep diary can sometimes help reveal patterns that aren't immediately obvious.

For autistic children and young people, NICE recommends considering the person's sleep pattern, bedtime routine, bedroom environment, physical activity, physical illness, medication, emotional factors and the impact of the sleep problem on the family when assessing sleep difficulties.

That broader approach is important.

The question shouldn't only be:

"How do we make this person sleep?"

It should also be:

"What is preventing this person from sleeping?"

What Does the Research Tell Us So Far?

There is convincing evidence that sleep difficulties are common in autism and that they can continue into adulthood.

Research also suggests connections between sleep and:

sensory processing
circadian rhythms
melatonin
anxiety
ADHD and other co-occurring conditions
physical health
environmental factors.

However, autism is enormously diverse.

One autistic person's insomnia may be predominantly sensory.

Another person's may relate to anxiety.

Someone else's may involve ADHD and delayed sleep timing.

Another person may have an underlying medical sleep disorder.

And for many people, several factors may interact.

This is why individualised support is so important.

Final Thoughts

Sleep is fundamental to our physical and emotional wellbeing.

Yet for many autistic people, something that appears simple from the outside — lying down and falling asleep — can involve an incredibly complicated interaction between the brain, body and environment.

Understanding this can help us move away from viewing sleep difficulties as stubbornness, poor behaviour or simply "refusing to go to bed".

Instead, we can ask what the autistic person is experiencing.

Is their nervous system still processing the day?

Is their bedroom uncomfortable from a sensory perspective?

Is their mind unable to disengage from thoughts or interests?

Is anxiety keeping them alert?

Is their internal body clock working differently?

Or is something physical disturbing their sleep?

Sometimes the most useful change begins with asking a better question.

At Aspect Autism, we believe that understanding autism means looking beyond what we can see from the outside and understanding the experiences behind behaviour.

We provide comprehensive autism assessments for children and adults, alongside post-diagnostic support designed to help autistic individuals and their families better understand their needs, experiences and strengths.

If you think that you or someone you care for may be autistic, or you would like support following an autism diagnosis, please contact Aspect Autism to find out more about how we can help.