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.

We have other opposite problems with circadian rhythms that can happen when you - a lot of times with older adults. They start to go to bed at 6:00, 7:00 at night and they wake up at 2:00 in the morning. And they're rhythms actually shift earlier, but sometime it can just kind of miss the mark and shift too much earlier and that's when we need to treat it with bright light.

There are some that are - REM Behavior Disorder, we'll see some court documented cases. And they really need to have a thorough evaluation with a sleep specialist.

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.

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.

We're not really sure why it [broken circadian rhythm] continues, but when they become adults, we usually have to treat it because many people need to get up early to go to work and they can't be sleeping until 11:00 or 12:00. So we use treatments like bright light therapy, melatonin, things like that that are very effective.

We'll work on relaxation strategies and also changing the times you go to bed will actually make them sleep a little bit less for a few nights so their body's natural sleep drive starts to kick in. That is very effective in about 60% to 70% of patients who do it, four to eight sessions, not even every week; it works for 60% to 70% of patients.