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.

So, it's not every patient that I see, but I'd say a good 70% to 80% of the patients when they go to bed it's like a stereo is playing at an 11 or 12 and they can't turn it down, at all. So it makes it very hard for their body to down regulate to be able to go to bed at night.

Now there's some night terrors that happen in adults. And if it starts as an adult and you've never had them before, then there might be other things that are happening; it might be anxiety, depression, stress. And that's when you might have more of a thorough psychological evaluation.

Some patients are still having insomnia, but it's seems worse to them than actually it is. So, if they say they're sleep deprived, they haven't slept at all in three days; if we actually take them into a lab, most of the time we actually do see they're sleeping on and off here and there.

So you have Sleep Stage One, Two, and then Three/Four. One is a little bit lighter stage of the quiet, non-REM sleep and then Three/Four is really deep, deep sleep. And what you want is, you actually want a number of - you want to go through all of these stages throughout the night.

Narcolepsy is a disorder that affects many different areas of life. So in typical patients with narcolepsy, they have something called "excessive daytime sleepiness." So, they're very sleepy during the day. Yet, at night, they're still sleepy, but their sleep is very broken.

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.