That Neuroscience Guy - The Neuroscience of Mental Health

Episode Date: November 16, 2022

The world has recently seen a widespread focus on mental health. It's necessary to understand what good mental health is, what happens when we don't achieve it, and how to improve it. In today's episode of That Neuroscience Guy, we discuss the neuroscience of mental health. 

Hi, my name is Olof Kregolsen, and I'm a neuroscientist at the University of Victoria. And in my spare time, I'm that neuroscience guy. Welcome to the podcast. So this episode of the podcast is basically a talk that I've been asked to give, where I was asked to speak on the neuroscience of optimal mental health. Now, we've talked about bits and pieces of this throughout the podcast series, but I've never really tied it all together. So when I was putting this talk together for my conference I'm going to, I thought, you know, this could be a good episode and it could be interesting. So I hope you all enjoy the neuroscience of optimal mental health.

So I guess you have to start with a definition, which is what do we mean by mental health? So even saying that, you know, what do we actually mean? Well, what most people think of when we think of mental health is that our brain is in a state where we don't have any negatives or a very few negatives and our brain is performing optimally. So as a neuroscientist, that's the definition I would take of optimal mental health. Our brain in a great state and doing what it's supposed to do without those little negative pieces. So as I go through this episode, I'm going to take you through what that means and some cases when it falls apart. And finally, right at the end, I'll do a quick review of some things you

can do to improve your brain and get optimal brain function and therefore optimal mental health. So it's important to realize that everything we experience comes from the brain. Now that should be obvious if you're listening to a neuroscience podcast, but think about what that really means. Everything you feel, everything you see, everything you perceive is generated within your brain. And it's important to start there. It's also important to realize that what's generating those feelings, like right now if you're feeling a little sad or a bit lonely or if you're happy, it's a product of neurons firing and neurotransmitter, which we've talked about in the past. So just as a quick review, we did this recently,

so I'm not going to spend much time on it, but think about how a neuron works. There's a cell body with information, which is basically an electrical signal, comes into the cell body through the dendrites, and then the neuron's job is to basically fire. And when it fires, it sends an electrical signal down the axon called an action potential. And when that action potential gets to the end, the terminal branches of the axon, it releases neurotransmitter. Most neurocommunication is electrical to chemical to

electrical. And it's when this process, even at the simple single neuron level starts to go wrong, that we have problems with mental health. Now, very quickly, I just want to talk about the developing brain. Now, assuming you have healthy development, your brain begins forming very early on. So at about 18 days after conception, the embryo begins to implant in the uterine wall. And this thickening of the ectoderm, which is a part of that, leads to the development of a neural plate. And we did talk and have an episode on the neuroscience of youth or growing up. And the neural groove, which is the precursor to the brain, begins to develop at 20 days. And this proceeds throughout development to the point that when a baby is born, it has a fully developed brain.

Now, there's still some changes that happen, but all of the key pieces are there. And when you look at an MRI scan of a baby's brain, and yes, it's tricky to do, but it can be done, you see this brain that looks like a human brain that's ready to go when the baby is born. So at seven weeks, you've got neurons forming rapidly, thousands every minute. At 14 weeks, the brain basically splits in half and you get two halves. At six months, basically nerve cell generation is complete. The cortex is beginning to wrinkle and get those folds that we see. And myelinization of the axons is occurring. And at nine months, when the baby is born,

we have a developed brain. Now, what I want to emphasize with this is that this is assuming healthy development. So this is assuming that when the baby is born, it hasn't been exposed to something like fetal alcohol syndrome. Now what happens after birth is basically you get a lot of neural connections being formed, and that's at its maximum density approximately six years old. But by the time you're 14, the neurons have been pruned away and you're basically just left with the parts that you need. So when we get to early adulthood, and I'm going to focus on mental health generically and not go into adolescent differences, but assuming that you get into your early 20s, you should have a fully developed brain with all the pieces that you need. you should have a fully developed brain with all the pieces that you need.

So how does this go wrong? So why do we have mental health problems? And we've touched on a lot of these before, so I'm going to walk through them pretty quickly. But let's consider something like depression. Basically, people with depression can have a couple of underlying factors. You could have problems with cerebral blood flow. That's been seen in some studies. But more commonly, it's a problem with neurotransmitters. And if you remember, neurotransmitters are the things that neurons are releasing when they fire. So neurotransmitters carry the electrical signal

from the axon across the synapse to the dendrite of the postsynaptic neuron. And various neurotransmitters do various things. There's acetylcholine, which plays a role in movement in memory. Beta-endorphin, which plays a role in pain or pleasure. There's dopamine, which impacts mood, sleep, and learning. There's GABA, which supports overall brain function and helps with sleep. There's glutamate, which plays a key role in memory and learning. There's norepinephrine, which helps control the peripheral nervous system, so the heart, the intestines, and overall alertness. And then there's serotonin, which also plays a role in mood and sleep. So you can see that if you start messing around with these neurotransmitters, you get problems. So for instance, if you have a lot of release of GABA,

that helps decrease anxiety and it helps decrease tension. Now, depression then, poor mental health, is caused by problems within the brain. And that's really the point of this episode is to point that out. If you take anxiety, the causes are inheritability. There is an inherited component. There are genetic markers for it. But more importantly, there's a biochemical disturbance. And it's our friend neurotransmitters again.

And when you start messing around with neurotransmitters with anxiety, that's when you get the increases in heart rate and breathing, tightening of muscles, difficulty swallowing, sweating, nausea, and the list goes on and on and on. If you get into social anxiety, it's again a problem with neurotransmitters, but it's also a problem with the firing of the amygdala. And the amygdala is not behaving normally. Stress. Okay, stress is a pretty simple story. The pituitary gland releases adrenocortotropic hormone, ACTH, and that stimulates the adrenal glands, which then release cortisol into the bloodstream. And cortisol and that release of cortisol and adrenaline too, basically can lead to increased blood pressure,

increased sweating, faster breathing, an accelerated heart rate, tunnel vision, and even your digestion slows down. So that release of these neurochemicals within your bloodstream impacts you just the same way that the release of neurotransmitter does. Loneliness, again, a problem with neural firing in different brain regions. Perceived self-worth, that value that you need to have likes on Facebook. I think it was our first or our second episode. Well, where does that come from?

It's dopamine. And problems with the midbrain dopamine give you problems with perceived self-worth. Even COVID impacted our brains. and we talked about this before, but now we're starting to see MRI scans of people where we've actually seen changes in brain structure because of the lockdown, and that's poor mental health. And you can get into some more, I guess, serious negative factors. As we age, our brains degenerate. Literally the white matter in our brains decreases in volume and that has an impact on brain function, which means you might become more emotional

or more susceptible to depression or something else. If we look at something like concussion, we see differences on the brain. And as we know from watching movies, advanced CTE leads to some crazy changes in behavior and people not functioning normally. Smoking changes in brain function. The brain function is not the same in smokers as non-smokers. In fact, there's less activation. Alcoholism. Alcoholism leads to a decrease in brain tissue,

which leads to a decrease in brain function, which leads to mental health problems. Cannabis. I hate to say that for the people there that like to smoke, but long-term cannabis use has been associated with changes in brain function, which have a negative impact. And the list goes on and on and on. Cocaine, yes, messes up brain function. So we've talked about this before, but how do you achieve optimal mental health? Well,

there's the classic four. I've added one since the last time. But sleep, I've mentioned this so many times on the podcast, but sleep is the single biggest thing you can do to help with mental health. Seven to nine hours a night, eating a healthy, proper balanced diet. Again, good mental health. One that I've added is hydration. I've gotten really into hydration and being dehydrated has a massive impact on brain function and actual brain tissue. Your brain begins to shrink a little when you're dehydrated has a massive impact on brain function and actual brain tissue. Your brain begins to shrink a little when you're dehydrated all the time. And of course, exercise. Exercise is amazing for brain function, and the recommendations are simple.

Try to walk at least 30 minutes a day or do something to get your heart rate up a little bit. And there's the new three, where I'll wrap it up. Social interaction is massive. We talked about that a lot when I talked about COVID and the impact of COVID on the brain. So be social and engage. It helps with positive brain function and therefore positive mental health. Mindfulness activities, meditation, breathing, yoga, and engage your brain. Things like Sudoku or reading or watching a documentary, do things to engage your brain because it will help with having optimal brain health and optimal mental function. So there you go. The reason that you have problems with mental health

is because of problems within the brain. But there are things you can do about that. is because of problems within the brain. But there are things you can do about that. Like I said, sleep, diet, hydration, exercise, mindfulness, social interaction, and engage your brain with activity. But of course, if you are experiencing mental health problems of any kind, it's important to see someone, your doctor, or someone that knows about these issues,

because some of these things you can treat by living a better lifestyle, but some of them actually do require medical help. All right, that's all for this week's episode. I'll see you on Wednesday for a neuroscience bite. Remember, check out the website, all right, thatneuroscienceguy.com. We've got links to our Etsy store where we're selling t-shirts. We've got links to Patreon where you can support us. Thank you so much to the small group of you that are giving us a bit of money. All of the money goes to grad students in the Craig Olson Lab. And of course, please subscribe to the podcast. We've got a few more episodes left in season four. We've got one next week on ADHD that was sent in by a user. So follow me on

Twitter at that Neurosag guy. You can DM me some ideas and I'll do my best to get them on the podcast. My name is Olof Kregolsen and I'm that Neuroscience guy. Thank you so much for listening. And like I said, I'll see you on Wednesday for a Neuroscience bite.