Workplace accidents with people who are sleep deprived or people who work shifts and they don't get the right amount of sleep during the day or at night.

In general, there are patients with insomnia who - many patients with insomnia will actually over report the lack of sleep that they are getting.

So when you go to sleep at night, if you're someone who hasn't had any sleep deprivation, you have a very normal sleep pattern, what we tend to see is that, in adults, they go to bed and they start off by going into the deeper stages sleep.

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.

We haven't really - it's harder for us to set those rhythms. So it's really important to keep a steady bedtime and wake time to really lock in those rhythms.

So when it comes to circadian rhythms, it's a clock that's basically programmed in our body. So if you think back to times when people lived on farms and we didn't have electricity.

When you are more awake at nights, they'll toss and turn, they'll think more, they get frustrated. And when that starts to happen, you really don't sleep even more because you're making your body tense and your mind is getting more and more active.