Your Brain On... Insomnia

Ayesha Sherzai (0:00)

It's 3 a.m., you're wide awake. Not panicked, but you're just on. Your brain is running tomorrow's to-do list, last week's awkward conversation, and the math on exactly how few hours you have left before the alarm goes off. And the more you do that math, the more awake you get. If that's you, three, four nights a week, you're not alone. About one in 10 adults meets the clinical definition of chronic insomnia. Most never get diagnosed, never get treated, and instead end up on a midnight scroll being sold magnesium pills, mouth tape, $300 trackers, and melatonin gummies. For us neurologists, sleep isn't just rest. It's when your brain does some of its most important work. As you sleep, your brain runs a cleaning cycle, flushing out the metabolic waste that builds up all the day, including the very protein linked to Alzheimer's disease. So night after night, year after year, bad sleep isn't just an energy problem, it becomes a brain problem. And it runs both ways. Poor sleep can speed up brain aging, and a changing brain can wreck your sleep. There's so much noise out there regarding sleep, so much sleep content engineered to make you anxious and then sell you the fix. So we brought in two of the sharpest people in this field to cut the signal from the noise. What actually fixes sleep? What's a waste of your money? And when is a bad night just a bad night versus something worth paying attention to? Our guests are two experts who come at this from completely different angles. Dr. Sujay Kansagra is a Sleep Neurologist at Duke University. He's the Director of Duke's Pediatric Neurology Sleep Medicine Program and an Assistant Professor in Duke School of Medicine. Sujay gives us the why, the biology of sleep, what's happening in your brain chemistry, and a brilliant, honest, rated rundown of every sleep aid you've ever heard about. Then we have Dr. Shelby Harris, who is a Clinical Psychologist and a Behavioral Sleep Medicine Specialist. She gives you the how, the psychology of why you can't shut your brain off, the trap of chasing perfect sleep, and the treatment that actually works. Much of her practice is Women in Perimenopause and Menopause, which she calls a perfect storm for sleep. And here's what struck us most. These two never spoke to each other, and they landed on almost the exact same conclusions. When that happens, pay attention. This is Your Brain On Insomnia.

So, let's talk about sleep, and why is sleep important?

Dean Sherzai (2:28)

Well, to think about it this way. A dolphin is air-breathing. So, in order to sleep at night, it actually sleeps with one side of the brain off and the other side on and alternates. In fact, one of the eyes are open and it's functioning, and the other side is completely asleep. Imagine that.

Ayesha Sherzai (2:44)

That's just mind-boggling.

Dean Sherzai (2:45)

That's remarkable sacrifice.

Ayesha Sherzai (2:47)

I wish humans could do that. Just shut off half of your brain and keep the other one on.

Dean Sherzai (2:51)

I could get so much done. But that's what the dolphins do, because they have to be able to breathe and come to the surface. Most animals, whether it's flies, worms, even jellyfish, which don't even have a central nervous system, have to sleep.

Ayesha Sherzai (3:05)

You never think of worms sleeping, but they do sleep.

Dean Sherzai (3:07)

They do. And everything that has some sort of nervous system has adapted this function of sleeping. Why is evolution, which is so efficient, introduced a process that puts these animals at such distress and sometimes at peril? Imagine one third of your life, all these animals who work so hard to protect themselves, that are so diligent while awake, that at night they shut everything off. They're blind to the world. They're deaf to the world. Their musculature is completely turned off. Their reflexes are not working. They're paralyzed. One third of their life. And the reason is because sleep is literally that important. Maintenance is an incredible machinery that maintains this incredibly sophisticated machine that's constantly working. The fact that a brain at any one minute has a hundred million functions happening at any one time. It's just remarkable. And it's also the most vascular organ. So the blood flow, the neuronal connections, the axon transfer of neurotransmitters through millions and billions of connections. That's a lot of work.

Ayesha Sherzai (4:12)

Just thinking about it makes me tired.

Dean Sherzai (4:13)

Exactly. So that maintenance system is necessary for all organisms that have any form of central nervous system.

Ayesha Sherzai (4:21)

Fascinating. So when you look at it from a mechanistic perspective, two main things happen when people go to sleep. The first thing is a cleansing system gets activated. And we can talk about the details of what that means. The second thing is your memories get organized and they get consolidated during sleep. But the cleansing system is just wonderful. It's such a fascinating feature of sleep. And it used to be theoretical and they studied it in animals. But recently they were able to image the glymphatic system and the cleansing system in the human brain.