What do you do when your cat refuses to sleep?

[Ivar]

I don't think there's any way to force a cat to sleep when it doesn't want to. My friend is having a serious challenge with his cat right now all efforts to get his cat sleep proves abortive. I told him to take the cat and see his vet for him to know exactly what's wrong.

Before he goes to the vet next week they have scheduled for an appointment, do you know of any way to help a cat sleep?