How Your Brain Constructs Your Mental Health

IRA FLATOW: This is Science Friday. I’m Ira Flatow. Later in the hour, reflecting on the fourth year of a global pandemic, what have we learned about how COVID-19 affects the body? And what’s next for long COVID sufferers? Plus, we’ll talk about a fish species which is a living fossil. That’s an animal which hasn’t changed much through millions of years of evolution. But first, a conversation about the science of mental health.

If you’ve ever struggled with a mental health issue like anxiety or depression or you know someone who has, it’s pretty clear that what works for you might not work for others. For example, antidepressants only work in about 50% to 60% of patients. Meditation or yoga, yes, can help some but be a waste of time for others.

And yet over the past few decades, we’ve seen huge advances in our understanding of the human brain. So how can we use the latest neuroscientific research to help improve mental well-being? To answer those questions and more, SciFri producer Shoshannah Buxbaum talked with Dr. Camilla Nord, Director of the Mental Health Neuroscience Lab at the University of Cambridge and author of the new book The Balanced Brain, The Science of Mental Health.

SHOSHANNAH BUXBAUM: Dr. Nord, welcome to Science Friday.

CAMILLA NORD: I’m so excited to be on Science Friday.

SHOSHANNAH BUXBAUM: OK. So I want to start out with the title of your book, The Balanced Brain. So what do you mean by a balanced brain?

CAMILLA NORD: So in my book, I try to deconstruct the idea of what mental health means. I don’t think mental health is about the absence of negative emotions and challenging experiences. Unfortunately, I think they’re completely unavoidable in life.

SHOSHANNAH BUXBAUM: Yeah. [LAUGHS]

CAMILLA NORD: But I think that what mental health really is, is your brain’s ability to respond adaptively to those kinds of frequent challenges that we experience. And the way that it responds adaptively is through what I call the balanced brain. But these are actually many, many different processes happening in the brain, integrating experiences that we’ve had, learning from them, forming predictions about the future.

Some of the experiences we have are from the outside world, as you might imagine, difficult, challenging things in the outside world, wonderful things we experience in the outside world. Some of them are from our inside world. It might be infections that we experience or other things communicated by our body. But together, these construct our brain’s model of our own mental health. And that’s what I call the balanced brain.

SHOSHANNAH BUXBAUM: What I found interesting is that one of the key pillars of mental health that you point at is drive or motivation. That’s not something that I traditionally think of when I think of mental health. So what do you mean by that? What role does motivation play in mental health?

CAMILLA NORD: So I want to speak about this both conceptually but also biologically because I think we all have an intuitive idea about what drive and motivation is. And that intuition is probably correct. So we need the motivation or drive to engage with the world in order to experience any of the many positive things that we might be able to learn from and build mental models of the world about.

And then on a more biological level, drive or motivation is often the thing disrupted that is most measurable across species. So if you look at animal models of depression or other mental health condition like experiences in rodents, for example, drive and motivation are some of the most measurable phenomena that we can see disrupted.

SHOSHANNAH BUXBAUM: I want to dig a little bit into that. So in the book, you start out talking about pleasure. And that’s obviously important for your mental health to be able to experience pleasure, want to experience positive things in your life. How does pleasure show up in the brain and relate to motivation?

CAMILLA NORD: So the reason I think pleasure is particularly interesting in the brain is because it has this relatively unique neural architecture from person to person. So this is reflected in the fact that the things you like aren’t necessarily the things I like. But in your brain, this is the specific hot spots of pleasure that are dotted around the brain, regions that if stimulated with electricity can cause the experience of pleasure.

They’re small. They’re distributed. And they’re also somewhat unique person to person. So it’s this very fascinating mapping of your likes and also your dislikes at a biological level in your brain.

And this is, I think, actually quite a distinct and measurably very independent system from the one involved in drive and motivation. So I’ll give the example of a much beloved neurotransmitter, which is dopamine. And one of the pet peeves, I suppose, I have about dopamine isn’t that it’s not great. I love dopamine as much as the next individual. But what we like about dopamine, as a society, is not really what dopamine is doing in the brain.

Often, what you hear people say, oh, I do dopamine dressing. Or I’m interested in a dopamine diet. Or I’m interested in a dopamine detox. What they’re really talking about is pleasure, which is not really something particularly coded by dopamine in the brain. It’s much more involved in other neurotransmitter systems, like opioids in the brain, endogenous opioids, which you might have heard referred to as endorphins. Dopamine is much more closely tied with motivation and drive, the desire to do anything at all.

SHOSHANNAH BUXBAUM: So I want to move on to a phenomenon that you write about, being hangry, this combination of feeling angry and hungry simultaneously. I’ve definitely felt this before. Probably listeners at home have experienced this. What does this help us understand about the connection between our physical and mental well-being?

CAMILLA NORD: What’s so cool about hangry isn’t just that it happens. Of course, if you have different kinds of biological disruptions– you’re cold as well, it can affect your mood. If you’re too hot, it can affect your mood. But actually, why it happens. So I’m also a prolonged sufferer of feeling hangry. It has a really, really big impact on my life.

And different people are and aren’t to different degrees, which is actually quite interesting. But the thing that it tells you about the brain is that the way that our brain codes for internal bodily states, like hunger, is very much overlapping anatomically with the way that it codes for emotions, like anger. And in fact, many would argue that the way that we’ve learned to identify what an emotional signal is by reading signals in our body.

So for example, if you are saying to yourself, oh, I think I feel a bit stressed or anxious right now, what you’re doing– one of the things that you’re doing is reading signals from your body. You might be reading your own heartbeat or your breathing. And your brain is interpreting that and making a prediction about why you’re feeling that way. And sometimes those predictions are wrong, are misinterpretations.

SHOSHANNAH BUXBAUM: Treatments that we have for a lot of common mental health disorders don’t always work for everyone. There’s often a lot of trial and error. And for example, the gold standard treatment for depression and anxiety is a combination of both medication, usually antidepressants, and psychotherapy. But you suggest that patients might benefit from taking some type of medication actually before a therapy session. So how might that work? What is that tapping into?

CAMILLA NORD: So at the moment, we treat patients relatively separately in terms of the treatments we think of as biological, like giving someone an antidepressant drug, and the treatments we think of as psychological, like cognitive behavioral therapy. But actually, these two things interact with one another. Some drugs probably increase or decrease the effectiveness of cognitive behavioral therapy. In fact, we have decades of neuroscience work in humans and in animals to suggest that that’s the case.

So I say a very interesting avenue– and in fact, I predict a very interesting avenue in the coming years for the future of mental health treatment will be a deliberate pairing of biological and psychological treatments– for example, drugs administered just before a session of therapy that will improve your ability to engage with or respond to or learn from the things happening in that therapy session.

This is, to some degree, already happening. There are good examples in exposure therapy for people with phobias, where some exposure therapy sessions are being combined with medications that increase your ability to learn from new experiences.

SHOSHANNAH BUXBAUM: Yeah. And I want to end on something that is– I don’t know– I thought a bit of good news when I was reading your book and that may help everyone, regardless of what mental health issues they are or aren’t struggling with, is that I was surprised when reading your book that it can be good for you to– well, good for your mental health– to do things that are a little bit bad for you– so drinking a beer, eating a cookie, or even skipping a workout, for example. It’s science, right?

CAMILLA NORD: I would say it’s individual differences. We all know what works for someone doesn’t necessarily work for the next person. But somehow, we drop this when it comes to mental health. We sit and we wait for that silver bullet that will address all mental health issues or a whole category of mental health issues, like depression or anxiety.

Now, probably, the most radical thing, I think, is that that silver bullet will never come. We should stop thinking about that model. We should be looking towards an individual model of what works for a particular person’s constellation of brain behavior, cognitive problems, and how those could be intervened with, with many different possible treatments, including drugs and therapy that I’ve mentioned but also brain stimulation but also lifestyle changes.

And those will not necessarily be the same between people. For some people, increasing exercise is an amazing resource for their mental health. And for other people, it might actually make them feel worse.

SHOSHANNAH BUXBAUM: Yeah, so I will feel less guilty about not being one of those people that just feels amazing from exercising.

CAMILLA NORD: Well, feeling less guilty is definitely good for your mental health.

SHOSHANNAH BUXBAUM: Absolutely. Dr. Nord, thanks so much for being on the show. This has been a really, really phenomenal conversation.

CAMILLA NORD: Thank you for having me.

SHOSHANNAH BUXBAUM: Dr. Camilla Nord is the Director of the Mental Health Neuroscience Lab at the University of Cambridge and author of the Balanced Brain, The Science of Mental Health. She’s based in Cambridge, England. For Science Friday, I’m Shoshannah Buxbaum.

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