 Sleep disorders and ADHD commonly co @-@ exist . They can also occur as a side effect of medications used to treat ADHD . In children with ADHD , insomnia is the most common sleep disorder with behavioral therapy the preferred treatment . Problems with sleep initiation are common among individuals with ADHD but often they will be deep sleepers and have significant difficulty getting up in the morning . Melatonin is sometimes used in children who have sleep onset insomnia . 
