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 the deeper stages of sleep are really those times of quiescence, you're really restoring your body and we have a few different stages of sleep.

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.

So, more times than not, but not every time, it can be linked to a medical problem, such as menopause, cancer, chronic pain, it can be linked to anxiety and depression. Those are the more common causes.

When they [people with insomnia] start worrying about not sleeping, I'll say, "Say the mantra to myself; if I don't sleep tonight, I'll likely sleep tomorrow, and if not tomorrow then definitely the third" because our body has a way of naturally catching up.

When you're in the more deeper stages of sleep - REM sleep, your body is quiet, but your mind is actually very active. So it's a time when your body and your brain is restoring itself. It's repairing any cell damage that happened during the day, it's really repairing, like I said, repairing your body, but also helps with digestion, helps with memory.

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.