I get asked very often for suggestions on children's sleep problems. We go down the basic suggestions such as keeping a consistent bedtime routine, not too much gross-motor activity 30-60 minutes before bedtime, keeping the noise down in the home, eliminating caffeine from the diet, putting away electronic devices 30 minutes before bedtime, and staying away from anxiety-inducing activities (e.g. if the child hates his hairwashed then do it earlier in the day not prior to bedtime). And then we start to analyze that particular child's possible problems related to sleep. For example, a child with cerebral palsy may need to be stretched and massaged so that his muscles can relax, whereas a child with an autism spectrum disorder may need lots of pillows confining the child in the bed along with a heavy quilt and "white noise" playing in the background for that additional calming sensory input. Sometimes those ideas work, and other times they don't. Although I have not ever personally used melatonin as a supplement for sleep, many of the families I work with have used it. Most of them have success and the child sleeps better. Some do not have success. Check out this article at the link below to to see if it might be of assistance to you or your child.
Melatonin and Sleep | National Sleep Foundation - Information on Sleep Health and Safety
As I type this half of my family is still asleep and it is 9 a.m. But I'm letting them sleep in since it is a holiday- Memorial Day! Thank you to all of the veterans who have fought for freedom for all of us in the USA!