Restless legs syndrome

RLS often occurs in children with ADHD. This includes many of those who already have nighttime cramping and jerking in their arms or legs. Symptoms of RLS include an uncomfortable tingling, burning, or crawling sensation in the legs when the child lies down to sleep. This causes an almost uncontrollable need to twitch, move the legs, or thrash around. Among those who have RLS, as many as 80% also have symptoms of PLMS.

Periodic leg or limb movements (PLMS) during sleep

This sleep disorder causes your child's arms or legs to cramp and jerk during sleep. The sudden movements may wake them up. Because these movements often jolt children awake, they can cause trouble falling back asleep or staying asleep.

Episodes of PLMS can last from a few seconds to nearly 2 minutes. They may happen often, too. The episodes may occur again and again over several hours. They may badly disrupt sleep.

If your child with ADHD is losing sleep from these involuntary movements, the resulting sleep loss can affect their mood. Behavior problems and irritability are common. Children with PLMS may also have symptoms of RLS as they try to fall asleep.

Causes

Experts don't yet fully understand the causes of PLMS and RLS. But they're looking at a possible connection with the central nervous system. Studies suggest that RLS is linked to a lack of iron or trouble processing iron, a mineral important to many brain activities. It's also been tied to nerve damage; conditions such as diabetes; and certain medicines, such as antidepressants and allergy pills that contain antihistamines. In some cases, symptoms of RLS will improve when the medicine is stopped. RLS has also been found to run in families.

Less is known about the cause of PLMS. But it also seems to be linked to iron deficiency and anemia. Kidney disease and diabetes may also contribute.

Researchers don't know why ADHD seems so often connected to these sleep disorders. They're trying to better understand the tie between them.

How these sleep conditions affect children

Children who don't get enough sleep can suffer in daily life. They may struggle to pay attention in school or have aggressive outbursts. Unlike adults, who tend to slow down when sleep deprived, kids may become more hyperactive the more tired they are.

In kids with ADHD, lack of sleep tends to make their symptoms worse. One study looked at the impact of improving sleep in children with ADHD. It found that consistently good sleep helped limit and, in some cases, even completely control symptoms of hyperactivity and inattention.

Managing ADHD and sleep problems

Medicines are commonly used to manage ADHD. But the stimulant medicines that are effective in controlling symptoms can often cause sleep problems, such as insomnia. Because insomnia can make ADHD worse, some parents choose not to use medicines for their ADHD. Instead, they focus on therapy, counseling, and social skills training to change the child's behavior. It's important for a child who takes stimulant medicine twice a day to take the second dose no later than 2 p.m. so that it's less likely to cause sleep problems.

Remember that children need a certain number of hours of sleep each night for their health. Grade-schoolers need 9 to 12 hours per night. Teens should be getting 8 to 10 hours of sleep every night.

These are other steps parents can take to control and prevent symptoms and help children with ADHD sleep better:

• Massage the affected limbs when they hurt.

• Do some stretches.

• Have an inviting bedtime ritual and consistent time for sleep.

• Get regular exercise.

• Remove the TV, video games, phone, and computer from the child's bedroom to create a distraction-free sleep environment.

• Turn off all TV, computer, phone, and tablet screens at least 1 hour before bedtime.

• Be a role model. Make adequate sleep a family priority. 

• Don't overschedule your child. Children need unstructured time to relax.