There are people who have repetitive nightmares. And what happens is their brain is trying to process the stress and help their brain actually deal with what happens if this stress happens again, so their brain's preparing them to deal with it in case the stress happens again, but it's so scary that they awaken from it.

There's a problem for them [teens] when they have to get up and go to school in the morning, they're very sleepy, yet on the weekends, they'll sleep 12 hours, they'll sleep late and then go to bed late and wake up late. And on vacations, it's not a problem.

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.

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.

There are other people that think that dreams actually do serve a purpose. But what that purpose is, we're not really sure. So some people believe that it actually does have some psychological representation of what's going on in the day, but there's no need to sit and really analyze it.

People tend to remember their dreams in the morning a little bit better and if earlier in the night, when you're in a lot of deep sleep, if someone wakes you, or the phone rings or something, you're really confused.

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.