He may have insomnia, you can try valarian root, to help him sleep better at night. I have insomnia, and have delt with it for years. You can also tame him to a doctor andask them what to do about it. Most medications don't work for alot of types of insomnia. I have been on just about all of them. Valarian root will help and it's all natural which is a plus. Hope this helps.
Try letting him listen to music. An iPod with music he likes and you approve of might help him settle. All my kids listened to music at bedtime (tapes then). They are good sleepers now and music lovers! They also read books until lights out.