Deep slow-wave sleep that you get, the very first sleep cycle, is when you get a big bolus of growth hormone release ... If you miss that first deep slow-wave sleep period, you also miss that big bolus of growth hormone release.

I don't think you can oversleep ... People who sleep over 9 hours, it's probably indicative of some other problem. Because, in fact, if you have a lot of different conditions, it will cause you to sleep a lot more, probably because what it does is it interferes with... the efficiency of your sleep. So, if you find yourself sleeping consistently 9 hours plus every night, then you might want to consult a doctor.

Alcohol is a REM sleep suppressant, and it even suppresses some of that stage 2 transition to REM with those sleep spindles. And those sleep spindles... they're really important for moving memories to our cortex.

Antidepressants... leave norepinephrine, actually, out there in the synapses. And what that does is it inhibits REM sleep ... You don't want to take them if you've experienced a trauma and you're experiencing PTSD. Because, if anything, it's going to make it worse or at least prevent the type of adaptive REM sleep that you really need in order to resolve those emotions and move on.

It's absolutely normal to wake up at least once in the middle of the night to go to the bathroom. And as long as you can get back to sleep in a reasonable amount of time, or even if it takes you an hour, don't worry about it as long as you have a lifestyle that allows you to then make up that sleep either the next morning or the next night.

When animals withdraw from opiates... sleep is disturbed. Our sleep is terribly disturbed, and the amount of sleep disturbance predicts relapse behaviors.

Most people, if they consistently deprive themselves of sleep so that they're only sleeping for 4/4.5 hours a night, build up cognitive deficit that just builds up over time. The more nights you have with sleep deprivation, the more cognitive deficit you have.

Waking up circa-sunrise... and going to sleep within 4 hours after sunset or so is actually better for the health of all human beings than is being a night owl. And there's almost like a night owl posse out there, especially on social media. They get very upset when you say that you should see morning sunlight ... The data on health metrics suggests that, sorry night owls, that they are wrong.

The first 4 hours of sleep are very important for memory processing. And in fact, if you learned something new that day or have experienced a new sensorimotor experience, then your early sleep dreams will incorporate that experience more than the later sleep dreams.

Do not take sleep talking seriously. So, no matter what people say, it doesn't necessarily reflect truth.

Women, or females rather, at high estrogen/high hormonal phases of their estrous cycle or menstrual cycle sleep a lot less, but that sleep is more efficient.

The density of our sleep spindles, the number that we produce per minute, is well-correlated with our intelligence.