- Sheena, guess who?

How's your night shift going?

- Listen, it is 6:00 AM EST, and I don't look like what I have been through, okay?

All my patients have been flipped and dipped.

I've given all my medications.

I am ready to go.

- I feel you.

It is 3:00 AM over here on the West Coast.

I'm on my ninth out of 10th night shift.

I am fried.

The last two years have been rough.

I mean, rates of anxiety, depression, so many mental health conditions have gone up.

We're all exhausted.

We all feel it.

- Stress is exhausting.

And a huge reason is because long-term exposure to stress can actually disrupt your sleep.

- For sure.

Long-term exposure to stress is like something a pandemic would cause.

In fact, a recent poll showed that nearly two out of three Americans have had their sleep completely wrecked during this time.

Either they're sleeping too much or too little.

- Now this is serious business.

Sleep deprivation has a huge impact on health.

It's linked to obesity, high blood pressure, heart disease, and a whole lot more.

- Now the phrase sleep disorders encompasses a large umbrella of conditions.

Some you've heard of, like sleep apnea, or insomnia.

And then there's less common ones you may've heard of, like sleepwalking.

- Sleepwalking has a medical name, it's called somnambulism.

And even though it's hard to say, to understand it we really have to understand healthy sleep patterns.

- Now let's take a look inside your brain and see what's up when you finally get to go to sleep.

When you're sleeping, your brain repeatedly cycles between two different types of sleep, you've got non rapid eye movement, or NREM, and rapid eye movement, or REM.

NREM happens first, it's broken up into three stages.

Each one of these showing their own rhythmic activity and electrical stimulation in your brain, or brainwaves.

Now the first thing that happens, the first thing that we see, is when you go from being awake to being asleep, and these are called alpha waves.

Next up, is when you go into a more relaxed state, the frequency of the brain waves get a little bit lower, but the amplitude gets higher.

And this is when we see theta waves.

And last, but definitely not least, is when you're completely passed out, and you're like a rock.

- This last stage is also known as slow wave sleep because delta waves with the lowest frequency and the highest amplitude happen here.

This is also the stage where sleepwalking is the most common.

- Normally, wakefulness and sleep are separate.

I mean, that's what it seems to be.

They're actually regulated by two different systems in our brain.

One group of neurons is called the reticular activating system.

And this group releases excitatory neurotransmitters that promote wakefulness.

The other group of neurons is known as the ventrolateral preoptic nucleus.

They release inhibitory neurotransmitters that promote sleep.

But when a person sleepwalks, I mean, something's up with passing the baton off between these two groups of networks.

- In this situation, some parts of the brain are still active.

Like the limbic system that's involved in emotions, and the part of the cortex that controls complex motor skills, like walking.

- The brainwaves look a lot like they do when someone's awake, but relaxing.

This is where a lot of your instinctual movements are stored.

At the same time, parts of the brain that control judgment and memory are inactive, like the prefrontal cortex and hippocampus.

They display the delta wave patterns we see in someone who's experiencing deep sleep.

- So that means that the part of your brain that handles decision-making is actually asleep, while the part of your brain that is responsible for moving around is actually awake.

So, you sleepwalk.

And this is also why many sleepwalkers don't remember what they did when they woke up, because the parts of their brain responsible for memory are asleep.

(gentle music) Now let's bust one myth.

Sleepwalkers are not acting out their dreams.

But that can happen with a different condition called REM sleep behavior disorder.

- Remember the ventrolateral preoptic nucleus?

During REM sleep, it releases powerful neurotransmitters that literally paralyze your body.

With the disorder, these neurotransmitters fail to inhibit movement, and some people show sleepwalk type behavior.

- It's so clear to see why sleepwalking can sometimes be funny, but people gotta be careful.

The most obvious risk is that they can be a harm to themselves or others.

- Yeah, some people can fall off a balcony, down stairs, break some bones, you can assault the person sleeping next to you.

Some people have even committed murder while sleepwalking, or so they say.

- One really interesting case happened in 1987.

A man named Kenneth Parks stabbed his mother-in-law to death.

He also stabbed his father-in-law.

Now, believe it or not, he was acquitted.

The jury actually believed that he was really asleep and that he didn't intend to commit a crime.

- Now NREM or non-REM sleepwalking and REM sleep behavior disorder are just two examples of disruptive sleep behaviors that we call parasomnias.

This includes things like night terrors, eating disorders, sleep talking, and sexual behavior.

Some unlucky people can even have multiple parasomnias.

So you could literally be sleepwalking, having a snack, and having a conversation with yourself, all at the same time.

Jenna has said that I've sleeptalked in the past.

- Yes, and you know what?

Sleeptalking, walking, all of it, really kind of just creeps me out a little bit 'cause I don't trust my brain without my conscience.

- Your brain's just running wild, right.

It doesn't make any sense.

- Right, I don't trust it, I'm scared of what my body wants.

Uh uh, nope.

So tell me Alok, do you remember it?

What did you say, what was it like?

- I don't, wait, so here's the thing.

I don't remember anything, obviously.

But like Jenna has told me, she's been like, you were mumbling last night.

And when I'm like, oh, you mean just like clearing my throat, coughing?

She's like, no, no, no, no, no, no.

You were like piecing words together, like babbling.

One time I said black licorice.

Why the hell would I say black licorice?

- Alok, is it true that you shouldn't try to wake a sleepwalker?

- Well I guess, yes and no.

I mean, waking up someone sleepwalking can be very disorienting for that person.

I mean, think about when you wake up in deep sleep from an alarm clock, or when your daughter wakes you up at 3:00 AM crying, and you wake up this morning and you're like, where the hell am I?

Now, if somebody is sleepwalking and they're gonna hurt themselves, yes, it's best you wake them up, take care of them.

Otherwise, just guide them right back to bed.

They probably won't remember a thing in the morning.

- I want to repeat, this is no joke.

The videos can look bizarre, but people who sleepwalk have a higher incidence of fatigue, insomnia, depression, and anxiety.

- So what exactly causes it?

Well, there's definitely some triggers, such as a lack of sleep, too much alcohol, caffeine, or even stress.

And then there's genetics.

In fact, if you have a parent who sleepwalks, you are three times more likely to be a sleepwalker yourself.

- Now, if it's not happening too often, you're not keeping yourself awake, or others awake during the night, and you're not harming yourself or others, then it's probably not a major problem.

But if you find yourself suffering longterm, then it's time to see a doctor.

The best treatment for sleepwalking is just to have good sleep habits, like adopting a regular sleep schedule, not eating right before bed.

And of course the one that we all struggle with, is reducing screentime right before bed.

It's really important that you know your personal triggers.

Some groups even recommend cognitive behavioral therapy to reduce stress and anxiety.

- How are you staying awake on this night shift when you have to deliberately sleep deprive yourself?

- Alok, I have my ways.

Let's take a look.

- (laughing) Game.

(funky music) - Alok, I bet you got some tricks up your sleeve too.

What you got going on over there?

- I have a few party tricks I do to stay awake.

I mean, I'm hypomanic at baseline, but I got some secret weapons.

(dynamic music) So everyone out there who's listening to Sheena and I ramble in our exhausted state, tell us, what's keeping you up at night?

Do you have a crazy sleepwalking story to share with us?

- Let us know in the comments and follow us back on our socials for more science-backed health topics.

Woo, I don't know about you, but I'm gonna take a nap.

Thanks for watching guys.

- Sweet dreams, everyone.

(dynamic music)