Really, a nightmare just really has to evoke some sort of, we call it, dysphoric emotion or something uncomfortable. You could be sad, you could be unhappy; you could be scared, anxious. But traditionally, the definition is you have to awaken from this nightmare.

I'll work on patient's thoughts about sleep, "So I must get eight hours of sleep tonight or I won't sleep tomorrow." That sometimes - or "I won't function tomorrow." That sometimes makes it very difficult for you to sleep at night

Now narcolepsy is really hard though because they're very tired during the day, they're sleepy during the day and it's managed mostly with medications. So we use medications to help them sleep better at night and to stay away during the day. But there are behavioral things you can do also by changing diet, exercise, having an actual nap schedule.

The other option we have are medication treatments. So you'll have the treatments such as Ambien, Lunesta, Sonata, and we'll also have Rozerem and for some patients we use Benzodiazopine/Clonazepam. Things like that to help with anxiety.

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.

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.

It's uncommon, but there are some people who just have a delayed circadian rhythm and they just - they sleep better during the day then they do at night. So they've - a lot of those people with delayed sleep phase disorder they start to work in bars, they work some of the late night shifts, they sort of adjust to doing it more and more as time goes on.