Sometimes a child's nightmares can be so petrifying kids will prohibit their own melatonin release.
I remember having really scary dreams when I was that age. Everything from having to walk through grizzly bear infested fields, to mummies trying to catch me and take all my feelings away, to black shadows stalking our family. I could not handle sleep. The problem was that I felt responsible to find a way to make these creatures in my nightmares stop what they were doing. I think if I would have known that life was about developing self-control rather than floundering to control everyone else I would have been much more successful in my nightmares as well.
As it was, it wasn't until I was much older when an English teacher in highschool taught us about how we could make decisions in our dreams and change their outcomes. Then my nightmares became something I actually looked forward to facing and I would try out different choices in my dreams and totally change them.
My teacher gave this example:
He had a reoccuring nightmare for most of his youth where he was running away from a bad guy. He knew all he had to do was leap over the edge of the bridge to reach the opposite shore to safety, but he always did it too soon and landed in the water instead and woke up mid-drowning. So this nightmare kept happening until one night where he consciously waited until he was at the end of the bridge to leap over the guard rail. Then he safely reached the place where the bad guy couldn't get him. I thought, well if he can be the master of his dreams, well, then I want to too. It kind of opens up a whole new amazing world for us as people. I especially now like to turn the tides of my own dreams and swim under water, fly, or diffuse a tense situation using validation.
However, the whole life approach of focusing on changing one's self is the most powerful lesson I got from all that and it is something one can use every moment of the day, not just in the night while they are sleeping.
Some other ideas:
We have a big library of children's books on tape. If they have a wired evening, the books on tape helps them a lot to wind down. I turn the story on about 15 minutes before lights out and they settle down to listen to it. I have 5 kids and it helps a lot on nights like that.
Another thing to consider is if you and your spouse are ones who enjoy each other's company in the evening or ones that despise it? Generally, if parents' hearts are respecting each other through the day and after bedtime a child tends to sleep better. Of course, that usually means the parents are modeling self-control oriented behavior and can educate their child on it through example and the sharing of wisdom.
Lastly, sometimes kids pick up pin worms and they are too uncomfortable to sleep.
