Children are more sensitive to the ADHD medication and thus are more likely to experience sleeping disorder symptoms than adults. One possible explanation for this is because even if children and adults take medication with the same duration of effects, children often go to bed earlier than adults. As a result, the medicine may still be in their system at bedtime, making it more difficult for them to fall asleep. Furthermore, children are more at risk of sleeping problems and disorders if they have a sleeping disorder that existed beforehand or have comorbid anxiety and/or depression.