How Does Mild Sleep Restriction Affect Children With and Without ADHD?

What you need to know

Even a small reduction in sleep time (about 20 minutes per night) can impact children’s attention and emotional regulation
Children with and without ADHD were similarly affected by mild sleep restriction
When children went to bed later, they partially made up for lost sleep by falling asleep faster and waking less during the night

How much sleep do children need?

Getting enough sleep is crucial for children’s health, learning, and behavior. But how much sleep is enough, and what happens when children don’t get quite as much sleep as they need?

Experts generally recommend that school-age children (ages 6-12) get 9-12 hours of sleep per night. However, many children get less than this recommended amount. Some research has found that even small amounts of sleep loss over time can affect how children function during the day.

This study aimed to look at what happens when children’s sleep is mildly restricted - meaning they get a little less sleep than usual, but not a dramatically shortened night. The researchers were particularly interested in comparing children with and without attention-deficit/hyperactivity disorder (ADHD), since sleep problems are common in ADHD.

How the study worked

The study included 36 children ages 6-11:

18 children with ADHD
18 typically developing children without ADHD

The children participated in two different week-long sleep conditions:

Typical sleep - Children went to bed and woke up at their usual times
Restricted sleep - Children went to bed 1 hour later than usual, but woke up at the same time

At the end of each week, the children came to a sleep lab. There, the researchers measured their sleep overnight and then had the children complete various tests of attention, memory, and emotional functioning the next day.

What happened to children’s sleep?

Even though the children went to bed an hour later during the restricted sleep week, they didn’t actually lose a full hour of sleep each night. On average, they got about 20 minutes less sleep per night.

This is because the children’s bodies partially compensated for the later bedtime:

They fell asleep about 10 minutes faster after going to bed
They spent about 15 minutes less time awake during the night after initially falling asleep

So the children’s bodies naturally tried to make up some of the potential sleep loss. This shows how quickly our sleep systems can adjust to try to get the sleep we need.

How did mild sleep loss affect children’s daytime functioning?

Even with only about 20 minutes of sleep loss per night, there were some noticeable effects on how children functioned during the day:

Attention

On a computerized test of attention, children showed some changes in performance after restricted sleep:

They were more likely to miss targets they were supposed to respond to
They made fewer impulsive errors (responding when they weren’t supposed to)

This pattern suggests the children may have been processing information more slowly when mildly sleep restricted.

Interestingly, parents, teachers, and the children themselves did not report noticing any differences in attention between the typical and restricted sleep weeks. So the effects were subtle enough that they weren’t obvious in everyday life, but could be detected with sensitive tests.

Emotional functioning

Parents reported that children showed more emotional lability/negativity during the restricted sleep week. This means the children’s emotions may have been less stable and more negative when they got a bit less sleep.

However, teachers did not report noticing any differences in children’s emotions between the two weeks. The children also did not report feeling any differently. So again, the effects were fairly subtle.

Memory and learning

The study did not find any significant effects of mild sleep restriction on children’s memory or learning abilities. The memory and learning tasks were fairly short, so it’s possible that more prolonged or difficult tasks might have shown some impacts.

Were children with ADHD affected differently?

One of the key questions in this study was whether sleep restriction would impact children with ADHD differently than typically developing children. Interestingly, the effects of mild sleep loss were very similar for both groups of children.

Children with ADHD did show more symptoms of inattention overall compared to the typically developing children. But the amount that their attention changed between typical and restricted sleep weeks was about the same as for children without ADHD.

This suggests that children with ADHD may not be more vulnerable to the effects of mild sleep loss than other children. However, since children with ADHD often have more difficulty with attention to begin with, any additional impairment from sleep loss could potentially have a more meaningful impact in their daily lives.

What does this mean for families?

While this study found some effects from even mild sleep restriction, it’s important to keep a few things in mind:

The sleep loss was very small - only about 20 minutes per night on average
Many of the effects were subtle and only detectable with sensitive tests
Children’s bodies naturally compensated for some of the potential sleep loss

So parents shouldn’t panic if their child occasionally stays up a bit later than usual. Our bodies have ways to cope with small fluctuations in sleep.

However, the study does highlight that even small amounts of lost sleep can have some impact, particularly on attention and emotional regulation. Over time, these small effects could potentially add up.

Some tips for helping ensure children get enough sleep:

Try to keep consistent bedtimes and wake times, even on weekends
Create a calm, consistent bedtime routine
Limit screen time in the hour before bed
Keep bedrooms dark, quiet, and cool
Avoid caffeine, especially later in the day
Get plenty of physical activity during the day, but not too close to bedtime

If you have concerns about your child’s sleep, talk to their pediatrician. They can help determine if there are any underlying sleep issues and suggest strategies to improve sleep.

Limitations and future directions

As with any study, there are some limitations to keep in mind:

The study only looked at one week of mildly restricted sleep. The effects of more severe or more prolonged sleep restriction may be different.
The sample size was relatively small, with only 18 children in each group. Larger studies are needed to confirm the findings.
The children knew they were participating in a sleep study, which could have influenced their behavior or performance.

Future research could explore:

The effects of different degrees of sleep restriction
How long the effects of sleep restriction last
Whether some children are more vulnerable to sleep loss than others
The impact of improving sleep in children who are chronically sleep-deprived

Conclusions

Even small amounts of sleep loss can impact children’s functioning, particularly attention and emotional regulation
Children’s bodies can partially compensate for later bedtimes, but not completely
Children with ADHD seem to be similarly affected by mild sleep loss as typically developing children
Consistent sleep routines are important for helping children get the sleep they need

While occasional fluctuations in sleep schedules are normal, this study highlights the importance of prioritizing healthy sleep habits for all children. Even small improvements in sleep quantity or quality could potentially have meaningful benefits for children’s daytime functioning.