Up to 85% of children with ADHD also have problems falling asleep or staying asleep. Medications used to help ADHD symptoms can sometimes cause sleep problems or make them worse. Long-acting stimulant medications and afternoon or evening doses of medication can make it hard for some kids to fall asleep. But, children with very high levels of hyperactivity might need stimulant medication to help them settle down enough for sleep.
Talk to your doctor about the dosage, timing and type of medication your child is taking. If your child has just started a new medication, wait at least 2 weeks for your child to adjust to the medication before making changes based on sleep problems.