There are some patients who just have insomnia and they've had it since they were a kid and we don't quite know why. So when we look at the cause, we definitely want to treat whatever else is going on, but insomnia often because it becomes its own diagnosis and that requires its own treatment.

So a lot of people who work rotating shifts and they work at night, their bodies are set to want to be awake during the day and sleep at night. So there are some people who have a lot of trouble adjusting their rhythms and they have trouble working the night shift, they're sleepy, they're drowsy driving home.

So people only focus on getting the really deep sleep, but in reality, we spend almost 60% of the night in the stage two sleep.

So, sleep deprivation, and sometimes an insomnia, which is a little bit of a different form, but just getting a lack of sleep, can lead to a number of different decrements.

Sleep paralysis is something that is actually very common. Many people have it, I've had it myself. And what happens is, when you're in that REM stage of sleep, your brain is very active. You're dreaming your most during that stage, you're mind, your eyes are moving, there's a lot going on. It's like fireworks going on in your brain.

We've looked at sleep diaries of patients with insomnia, and they'll say that they don't sleep for one or two days. And the body actually has a natural function, after about the third day to start catching up and you get a little bit more sleep the third night. And that's usually what I tell my patients.

Well, the actual function of the brain, not so sure yet. There's a lot of different theories about it, but when you talk about psychologically in your brain, a lot of people with insomnia, though not all, report that they can't turn their minds off.