Sara Rigby: Hello and welcome to the Science Focus Podcast. I'm Sara Rigby, online assistant at BBC Science Focus magazine. In the UK, one in four people experience a mental health problem each year. The reality of living with common problems like depression and anxiety is increasingly well known. But how much do you actually know about what's going on in your brain when your mental health suffers? Neuroscientist Dean Bennett, author of the new book Psycho-logical, is here to tell us all about it.


So can you first please just tell us what your book is about?

Dean Burnett: It's Psycho-logical. Two words, very clever. It's basically a book about mental health, but not... Unlike most mental health books you find in the market, all of which I find, it's not a sort of slur against anyone else, but it's a book about mental health as a process, as a scientific phenomenon, which we, sort of, we have a recognition of, an understanding of what's going on internally when our mental health declines or suffers or is compromised in some way. Because there's a big push now, has been for many years, for mental health awareness, to raise awareness of it and to increase understanding. But personally, I've always felt that as good as that is and as noble and as useful there is, awareness is only part of the battle. I think you need to have an understanding of what's going wrong before you can really have any sort of genuine appreciation for the matters. Because if I'm being very pessimistic, I would say the majority of mental health awareness campaigns, you can boil the message down to something like: depression is real, pass it on. Which is fine. It's a very valid thing to say. But it's also like, well, that's not really the most persuasive argument. So I thought, well, given I spent 20 years dabbling... Dabbling? I'm not a dabbler. I'm a neuroscientist. I've got a PhD and everything. SA bit of that imposter syndrome phenomenon. But, um, yeah. So I know I've been working on neuroscience for well over 20 years now and from undergraduate level and I spent like seven years as a psychiatry lecturer for a master's course. So my knowledge and experience is very much a wide range in terms of the underlying science rather than the actual everyday experience. So I thought, well, maybe there's room for that side of things to say, like, well, yes, we all know most people agree that mental health problems are genuinely real things and they affect us all in many different ways. And if they don't affect us directly, society itself is affected by them. But why? Why does this happened, what's going on in our heads when mental health declines, what we know about it and what can be done about it and why does it keep happening? That's the sort of questions I wanted to tackle in this book, particularly. So it's focused on mental health, but the actual the science of it insofar as we know. So that's what I that was my attempt to do. And some people might read it and think I failed. But that was the that was the intention.

SR: So generally speaking, what is it in our brains that can go so wrong and cause mental health problems?

DB: Well, that's a hole with no bottom, isn't it?

There's a lot happening in that brain, which in any one part of which can be compromised in some way, which can suffer for it. Pure quirks of biology to the external experiences to unrecognised issues of development. There are so many different factors which feed into it. And like a mental health problem manifest in so many both varied and intangible ways.

I mean, you can't... That's one of the big problems I address early on in that there's a lot of comparisons made lately with between mental and physical health problems. And I think my my argument would be that there are times when that is a very valid thing to do, that is suitable and helpful approach. When you're dealing with someone who doesn't recognise mental health problems or doesn't agree that they are a thing, it is almost inevitable that you will contextualise them in the form of something they will recognise. Or even if someone says depression is not real, there's no such thing as mental health problems. You very rarely find a single person who would say the same thing about physical ailments because everyone's had something at some point. I mean, the human body is not a perfectly flawless machine. You don't go through life never having even as much as a stubbed toe or a cold or a headache or a broken bone or an injury of some sort. So these are, you know, people recognise these. And if they don't have themselves, they can see other people have around them. And you can see them. You can see like, well, what we know how the human body is meant to look. So if it's growing extra lumps and it's turned green, that's wrong. There's something really, really going awry there. But you can't really do that with mental health problems because the manifestation of them in the real physical world is other people's behaviour, which is always changing, always in flux, because we are complex creatures. But even having said all that, I thought, well, it would be good to maybe try and impose some tangible aspect to it by looking at the brain, since that's where all our thoughts and behaviours and emotions and moods arise from. So there's plenty go on. The brain can go physically awry or physically wrong. And we can look at that and say, well, that's what's causing this mental health problem to recognise it.

So in terms of the underlying biology, there's a lot of things going on, but a lot of it seems to come down to - we're talking about the more common mental health ailments, we're talking anxiety and depression and things related to those - come down to, sort of, it seems to be an end result of stress in some form. And stress, it's a common term now, sorry to say, in almost an offhand manner. So work stress or the stress of everyday life, but it's due to genuine physiological process in that it's the precursor to the fight or flight response, like your body getting warmed up to deal with dangers and threats. And the way I describe it is if the fight or flight response is like the big bad boss in the computer game, stress is the hordes of minions they send at you that you have to wade to to get to that point. And they're not as potent and powerful as the big boss.

But they can do a lot of damage. There's more of them than they wear you down eventually. And one thing, as impressive and brilliant as the human brain is, and all it's evolved to do, one thing and seemingly hasn't evolved to do it - so far as it's evolved to do anything. Evolution doesn't have an endpoint. It just keeps happening. But long term chronic stress isn't something the brain has a good ability to deal with because it to happen in the wild, things that stress you out would be immediate dangers and threats or things like that. Even if it's like low food supply, when you find something, the stress goes away. But because we have these big, powerful brains, we can envisage scenarios which will negatively impact us without physically hurting.

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It's like losing a job or a relationship going sour or people get stressed out by the idea of the economy going downhill and their savings not having as much value. These are things which do not have any direct physical impact on you and you have no control over. But you can worry about them and they might never happen. People can get really stressed out about things which haven't happened and may never happen. And sometimes we get stressed about things which definitely did not happen and now cannot happen. We've probably all done it. Like you think, you cross the road and a car speeds past. Oh, a second earlier, if I crossed earlier that could have hit me, I'd be killed. And that stresses out that didn't happen.

We know that. But it cannot physically happen, we can't go back in time.

But we get stressed anyway. So and the constant low level of stress chemicals impacts on our brain and body in various different ways. And it can lower the immune system, can exhaust neurones. That's one of the leading theories of how depression works. Now, it's not about chemical imbalances as kind of an old school theory. No, it's not that the chemicals aren't gone different how they should be. But that seems to be more of a symptom, not a cause, in that neurones become exhausted by the constant stress chemicals. So they were shut down. They're going to stand by like they just do the bare minimum what they can. And some of those are parts of the brain which control mood and how we change mood and shift and respond well to things. So that feeds in quite nicely a lot of the typical symptoms of depression, the inability to change from a low mood, inability to feel anything in response to something positive or the complete lack of motivation. It makes sense to think big chunks of my neural networks, which allows behaviour that's currently suppressed, have just been spent by the stress response. And similarly, in different parts of the brain, the stress chemicals are like the threat recognition, recognition stimulate those parts of the brain, which keep us on edge and look for dangers. And if those parts are overworked, maybe they'll become like a muscle. They get more powerful and stronger. They tip the balance and therefore you get anxiety when people are constantly worried about things, which may not be there. There is a low level state of panic because the part of your brain which respond to threats and dangers are now being overworked and they get overstimulated and sort of beefed up. And that is a very simplistic way of looking at it in that it's obviously a lot more complex than that. But if you look in these terms, you can understand all that. It makes perfect sense that would happen because the modern world is so generous with things, the stresses out and the human brain can find them even randomly. And therefore, you get all these abundant cases of anxiety and depression and things like that because the world is seemingly set up and the brain works to the way that these things are pretty much inevitable.

SR: Right. So let's talk more specifically about depression. And if, as you say, the the world is generally quite, quite stressful, surely we're all exposed to that. So what what is it that triggers depression in particular people and not in everybody?

DB: Yeah, that's a very valid point. We're all kind of expose to that. To me, I think it's sort of misleading to think there will be one root cause of depression or any mental health problem. It's always going to be a combination of factors like the heritability factors when it comes to depression, people of certain types from certain families. They have a higher risk of depression, so like if your parents or one of your parents had depression, like the odds of you having depression increased because you don't have the right genetic factors which lead to it, or lead to a vulnerability to it. But that doesn't mean that if you have this gene, you will have depression. If you don't, you won't. It's just no, it's a balance of risks. And that if the average person is five per cent chance of having depression, then someone with this gene that will have 10 per cent chance, both unlikely, but one is twice as unlikely as the other and so on. So there will be genetic factors which link in things like certain gene which doesn't, which is so slightly distorted or just different to the point where it doesn't produce enough growth hormone, which means part your brain won't be as resilient or well-connected as others, and therefore depression can occur because it doesn't lead to the stress and so on and so on. So little things like that and childhood experiences, if you were growing up in a sort of more traumatic environment or just a less stable, more chaotic, more confusing, more stressful one, then your brain will develop in certain ways which perhaps will be wary of stress or seek it out even more, because you've grown up thinking, well, I should be, my childhood experiences say that the world is a dangerous place, so I will be constantly wary of dangerous things.

And therefore you look out, then you become more stressed that way, or even just like nutrition. You don't build up the physical resilience in terms of how the brain works to fend off things. I mean, the brain, there's so much redundancy and it's so much failsafe and so much extra processing which can take over, it's all flexible that in people with brain injury can make good recoveries, especially the young, because the brain is still developing and we'll find workarounds. But these abilities are finite. And some people, if you've been dealing with stress a long time or if you're already sort of running in a bit of a loss is a way of saying it. But if you're already dealing with a predisposition to stress or low mood, your brain's constantly working harder to fix that, to do that, to deal with the consequences of that so that when something else happens, like a particularly strong life stress, like the stress scale, like the maximum thing that can happen is the death of a partner, the death of a spouse. And it goes down from there like things like like retirement can be very stressful if you plan to do it, because it's a massive change your life. Divorce and things like that. These are all big triggers of stress. And if you already have a lot of stress to deal with, then that can be enough to push you over the edge and to right now, now your brain's suddenly gone 'I genuinely cannot handle this anymore' and therefore just don't spirals from there. Like, 'I can't handle this, I'm going to shut down for a bit.' And then you have your depression, you have your anxious episodes, you have you quote unquote, nervous breakdowns as people tend to refer to them. It will push you over the limit in the brain from can cope to can't cope. Where that line resides is going to differ for many different people. And someone predisposition. Some will have a lot of cognitive reserve and that can be a big deal. As lot of studies have shown that how adept and healthy, how much resource your brain has, can be a massive protective factor to stave off things like dementia. And if you have the underlying pathology people who have lived healthy lives and constantly kept learning things and stay active and use their brain, they tend to show very little symptom or sign of dementia, even if their brain has... If you took a sample of their brain, surely this person's got terrible dementia, but they don't. And because the brains are alert and active and capable but for many people in the modern world doesn't allow them to build up this reserve, it takes and takes rather than allows them to give and give. And some people will end up with depression as a result of that. So, yeah, there's loads of factors, but it's not, I think, important point that no one's a failure. If you've got depression, that's I think it's the capacity to lead that sort of thinking. But it's it's going to happen in the way the world works. And it's just it's often the case of someone who's got depression or had depression, they had a lot more to deal with than most people.

SR: You mentioned earlier that bereavement was one of the most stressful events that the brain could deal with. So in in grief, people tend to feel a lot of the same sort of things as you'd expect to be symptoms of depression. So, the low mood for a long period of time, things like that. So what exactly is the difference between grief and depression?

DB: Yeah, so obviously this is a very big issue at the moment because we live in the middle of a pandemic. And as I find myself, like I lost my father very early on the pandemic and it was very unexpected, he had no prior health problems. He wasn't even 60 yet and it came out of nowhere. And I had to deal with that all by myself. So I do delve into that, obviously, the book and stuff. And it was extremely traumatic, extremely debilitating and a very hard time. So I can speak from experience in this regard. And it was less than a year ago, I wouldn't say I'm over it, but I'm functioning and it can still be rough. Me being a neuroscientist who deals with mental health. Was that helpful for dealing with your own grief and stuff? I think it was in hindsight to me at the time, it didn't feel like it was helping, but I never got to the point where I couldn't function. So maybe there was a protective factor in knowing how this works, what's going on in my head when this is going on. But on the other hand, it's also the analogy I use. It's like being a trained mechanic trapped in a car with no brakes on the motorway. You know, I know what the problem is. I can't do anything about it right now. I'm just going to wait until this is over and hopefully I'll survive the whole thing. So, yeah. So it can be a helpful thing. So this is why I always try and educate people or say the more you know about what's going on, the more resilient you can be, because this is not scary or uncertain. You've got a handle on what's happening. But back to question. Yeah. So how are you diagnose grief and depression is a it is a tricky one. It is actually.

It's an ongoing debate and it can be a source of controversy like the DSM, which is the the American Psychiatric Association, their go-to manual for what counts as a mental health problem or doesn't, a diagnosis or not. And the fifth edition was revised a few years back and people were quite alarmed by how many things now count as a psychiatric diagnosis that before you'd think they were just general human behaviour, like people say tantrums, having tantrums is now recognised as a psychiatric problem. I think with kids just have a tantrum. That is another case of over medicalising, trying to sort of find problems. The pharmaceutical companies can charge the medicines and make a lot of money off. And that's definitely a problem which does have to be or should be addressed and paid more attention to. But the other side of the coin is the you know, the people would argue that before now, kids who had chronic tantrums to the point where they couldn't control the behaviour and their parents can do anything about it, which is clearly causing disruption, they would be diagnosed as having bipolar problems and would end up on far more severe medication, like far more powerful stuff, which you would rather not do for a small child. So if it's a tantrum as a separate diagnosis, all you can do is that maybe you can give them a much milder intervention or some sort of therapy rather than powerful medications.

So there's two sides to every argument. The grief thing is a tricky one in that, like you say, when you lose someone close to you, it's the most traumatic, harrowing experience possible. And you will show behaviour and think in an emotional and mood symptoms which are very similar to that depression. The general approach I'd like to make out is that it's a question of how long it lasts because people in grief will be laid low for weeks, months at a time, depends on the nature of how it happened. But if it's like after six months, nine months, they still show no signs of any change in their behaviour and thinking, then that's where a chronic grief reaction comes in like this. OK, so now we can probably have some of the intervention here because they clearly aren't moving on. They aren't processing this. It's a serious emotional change with a huge emotional impact on them, and these things take time to work through, but they do eventually happen and the brain is adept at doing that, that we are very emotional creatures, but we also have a lot of processes in place in our brains to work through these things. And if you're not showing any sign of that, that's that's when you can sort of say, OK, this seems like it's a problem rather than just the normal process. So it more comes down to how much change there is. I mean, that's how depression is sort of diagnosed anyway, not over a period of months, but weeks. And people have low moods all the time. You know, it's very common to be sad about things, especially now we're in the middle of a pandemic. You know, lots of things are going wrong and there's lots of things to be unhappy about in the wider world. So people being in a low mood state, being unhappy, being sad, being just like I can't be bothered, I can't do this anymore, is common. But the difference between that and depression is, A, severity. People with depression tend to be very, very low mood rather than just a brief melancholy. But perhaps even more indicative is how long this lasts because a mood doesn't normally last two weeks. Your mood can change a couple of days or you have ups and downs from the mood is unchanged or stays the same for two weeks or the best part thereof. That's when you think, OK, this doesn't seem right because the brain doesn't do it's the same constantly, the mood and emotion and thinking. So, yeah, it comes a lot of it comes down to just the duration of the symptoms rather than what the symptoms actually are themselves. That's like a big, interesting aspect which people seem to not really recognise and that, yes, we have we all have these different emotions and all of these bad and good experiences. But how long they last can be the deciding factor between general brain behaviour and mental health problem.

SR: So, as you say, there will be a lot of people at the minute going to bereavements, not knowing what you know. Now, what advice would you give to them to, I suppose, experience grief in a in a healthy way?

DB: Yeah, it's a little tricky in that obviously everyone's going to be different. From each their own. People are going to have different experiences of what they're going through, how it happens, how it manifests, who they have with them, what the situation is. Because like I would say, it was particularly hard for me when it happened because it was a middle of the earliest lockdown where we were cut off from family. I don't live down the road from my family. I'm like 30 miles away from my closest relatives. So I had no one I could really depend on. Normally when this all happens, you lose someone very close to you, people rally around, they gather around. They do things for you, like they take care of the kids, the house, the cooking and stuff, and they just pop in to see if you're OK. It's a very human compulsion and a good one, a very healthy one. But we couldn't do that. On top of that, I live with my wife, my two small children. There were three. So it was lockdown. They were scared, out of school. They just lost their grandfather. They didn't know what was happening. So I couldn't really afford to indulge my grief in terms of just sitting around doing nothing, which is what I wanted to do. I had to still be strong and provide reassurance for them. So it's really hard to do that. I did it and, you know, it did cost me, but I did it. And I was lucky enough to have the resources to do that. I've lived a relatively charmed existence the past few years in terms of nothing particularly bad happening. You know, I've no particular concerns and stuff. So it's. Yeah. So like I was in the position where I could do that. I thought I was hit with a particularly hard version of it, but also had the resources to throw at it. Mentally, cognitively, and not everyone will have that. And I think it's important to recognise that there's no particular path through grief which you have to take or you should be following. I mean, it's a very common cultural reference. The whole five stages of grief, denial, anger, bargaining, acceptance or some variation of of that. I mean, it pops up in sitcoms all the time in films. And when you experience grief, you go through these five stages and that's how it works. But that's not really how it works at all in that I mean, the human brain is never that predictable, not reliable in any case, especially when it comes something which is a really profound emotional experience. That's where it gets its most chaotic, most unpredictable. But even the psychiatrist who came up with these group stages, she never said originally that everyone will go through these stages of grief at all times and in this order, the more like a recognition of the path of grief which can occur more sort of common flustering things, and of this person grieving and they seem to be experiencing denial or this person seems very angry and that's fine. But it doesn't mean that that's before fear, that's after the denial. So there's no logic to that. So even if you're grieving and you find yourself confused by your emotions, your experiences, your reactions, then that's fine, there's no sort of template for this that you have to be following and I think it's really important to keep that in mind. Everyone's grief is going to be their own. They're going to know. I mean, I got very angry a lot for no reason. People messaged me with very positive things, expressing sorrow on my behalf and saying they wish they could help and stuff that was clearly well meant. Clearly a friendly gesture, clearly heartfelt, comes from a place of love. But I kept getting really angry at that at first and that you wish you could help. But, you know, you can't. It's a lockdown. My father died. There's nothing you can do. This is making yourself feel better. How dare you? And I didn't say that to anyone, but it went through my head a lot and at the time it felt wrong. In hindsight, I realise now that that's OK. As long as I wasn't hurting anyone, I would express my feelings that way. Then so be it. That's what I'll do. So yeah, I think it's important to recognise, especially now when we sort of cut off from so much and we have so few options for. And mental stress or, you know, because I feel better, all your pastimes of leisure pursuits, it all cut off for the time being. So when you mention grief, you would be doing it in your own way. And that's important to recognise that your grief is your own. And if it's going this way for you, then that's how it is. You know, if it's going another way, that's fine. If you stay stuck in one place for too long, then, yeah, then you can sort of start being concerned. But if you work through it how you need to work through it then nobody can tell you that this is wrong, you should be doing this. That's when it could be made worse, I think.

SR: So if someone is suffering from depression and they decide to go get help for it, they might get they might get prescribed some antidepressants. What do antidepressants actually do in the brain?

DB: That's kind of an interesting one. I mean, I think to me it's been a good sign that the mental health awareness campaigns are working in recent years because I started writing about stuff like this over... at least 10, 15 years ago. Between that, not all the time, we still see a lot of arguments online... Obviously online arguments, where else do arguments happen? We know that. But it's people dismissing depression as a thing. Saying no, no such thing as depression. It's people attention-seeking, drama queens. Just snap out of it and all that sort of stuff. And you still get that occasionally from the more extreme controversial pundits. But more often than not, now depression is accepted as a real thing. Now it's all go-to argument is that antidepressants aren't a thing. It's a just a scam. They're just some big pharmaceutical companies push on us to make money, or like, you hear so many people encountering someone, and they're like personal trainers, the first thing we do is get you off those pills and then it's judgement and sort of stereotyping and pill shaming of people on antidepressants. So there's a lot of work to be done there. But, yes, it's it's a controversial area, I suppose, and written books about it and how you shouldn't take any depressants, which is wrong and bad in so many ways. And so what they do is... If we turn to the class of antidepressants you've got in that... There are lots of different variations available at the moment, like the mainstream ones which have been validated and sent through trials and just readily available and, you know, tricyclic amines, you've got monoamine oxidase inhibitors, you've got your SSRIs, your SNRIs and so on. But what they all do is some variation on increasing the levels of certain neurotransmitters in the brain, which I believe is where this whole chemical imbalance argument or belief comes from in that you've got your regular brain, you've got some levels of certain chemicals, namely neurotransmitters, which the brain needs to do everything it does. A set of neurones communicate with each other and in people with depression, in this case, some of those chemical levels are reduced for reasons unknown, and that causes depression. So if you can take an antidepressant, it puts those levels back up and that cures depression. That seems to be the assumption or the view of it by a lot of people. This chemical imbalance claim is quite widespread. But I mean, it's logical to make that conclusion because it's like antidepressants were discovered essentially by accident in the 50s when they were looking for different things to take on to deal with surgical shock and they found people's mood sort of been elevated. And it took them long enough to know something was up here. And they found that there are anti-depressants and that's what they do, like they stop the removal of neurotransmitters after they've been used. They stay around longer, so brings the levels back up and so on and so on. But the main thing is like the neurotransmitter antidepressants work on the chemical level right away. You take on your new levels are increased like minutes later. But most of the widely available antidepressants now, they take between two and three weeks to kick in, which is a long time. And it's weird, because if they work straight away chemically, why do they take so long that any actual relief of the symptoms of depression. And this reveals that it's not just on the chemical levels, it's something more profound than that. It's been more deep and complex. And to go into like the neuroplasticity thing from earlier, it's now sort of believed by many that what antidepressants do is they sort of slowly but surely build up the activity in these suppressed neurones by causing more activity to act on them, by boosting transmitter levels. So, sort of like blowing on the spark of a campfire, just like coaxing it back to life. And one of the things of that is that pretty much all modern antidepressants, not all, but all the main ones, they work on monoamine neurotransmitters, which are all the various neurotransmitters, you know, adrenaline, your dopamine, your oxytocin. These are all monoamine class. It just means like there's an amine molecule attached to the general thing, which are very important neurotransmitters in the brain. But they take up a relatively small percentage of the brain, sort of like in terms of how the brain mass is layered or how it works. The monoamine systems are like sort of the veins that run through marble. Kind of everywhere, but a small part of it. And so if you boost activity in the monoamine system, which all antidepressants do at the moment, pretty much all of them, they will have sort of a more slow and gradual effect because they're not really affecting that many neurones in the brain. But the activities are spread out slowly, like fertilising a plant. You sort of just put it in there and it slowly seeps out. And but there's been sort of a lot of developments recently into more potent antidepressants. In 2019, in the States, the first ketamine antidepressant was released for use in early trials and stuff.

And it's a nasal spray, not even a pill, and it seems to work the next day or maybe even a few hours, because ketamine, for all its faults, is a very potent chemical. It works on the glutamate system, which makes about 80 per cent of brain activity. So it's rather than sort of blowing gently on a campfire, it's sort of like cranking up the flame thrower and just firing at it. Just like, take this. Ahh!

And it's like the brain just kicked up into, like several gears, like woah, hello!

SR: Sorry, I'd just like to pause there for a second. So we're not actually recommending that people go and take ketamine.

DB: Oh yeah, I was gonna get to that, yeah. So, so does that. And the same thing with hallucinogenics, like magic mushrooms and things of the chemical derived from those. They stimulate so much of the brain that it's believed they can sort of get those sluggish neurones back to a regular activity a lot faster. But obviously the downside of that is you stimulate all the brain in one go with one chemical, you're stimulating all the brain in one go. The brain does a lot of things. That can be seriously dangerous if not done right and not done with extreme expert interventions and refinement. So I guess this is not a recommendation. Don't go find it and take it, because that will, well, if you do that, maybe depression will be the last your problems. It's going to cause a lot more problems than not.

SR: OK, thank you. Um, and so we've talked about depression in terms of in terms of your brain's ability to change its neurones and neuroplasticity and stress and chemical hormones, imbalances and things like that. But I know that a lot of people who are suffering from from depression get talking therapies. So what can a talking therapy do to the physical structure and behaviour of your brain?

DB: Yeah, it just seems sort of like they're an odd leap to make, that you can talk someone into having sort of a reenergised brain. Well, the best therapy seem to be a combination of antidepressants and talking therapies, because you could argue that antidepressants will boost your brain activity back up to normal levels, but talking therapies can then sort of channel that new activity into more helpful, beneficial routes. And because I think a lot of talking therapies essentially just to them is trying to coach people or train people to think in or instinctively think in ways which are more beneficial than the usual, negative routes. Someone with depression will have a very negative mindset. Like they reflexively think the worst is going to happen or the worst has happened, or they are unpleasant person unworthy of love and respect and concern and things like that. And if you can stop them doing that, that can sort of break the cycle because a lot of these mental health problems are kind of self-fulfilling. Then if you're anxious, you look for things to be worried about. And because of how full our brains are, you'll find them. Exactly, I should worry about that. They should have been a big thing to worry about. I mean, I think it's quite telling that for diagnosing depression, you have to have the symptoms for two weeks for diagnosis, according to both the ICD 10 and the the of the DSM. The the main text for mental health diagnosis, so for depression is like two weeks of sustained symptoms. But for anxiety, it's in the region of six months, and which sort of shows like how much of our modern life anxiety is kind of a default. Yes. Are you worried about this? Yes. It's hard to think of that. I think if you're planning a wedding, that's a really big, big deal. It's a lot of work, a lot of pressure, a lot of effort. And it's a massive life change, if it's your wedding, of course. And that can take six months. So you can have six months of the symptoms of anxiety of just be constantly anxious and stressed for six months and have a perfectly valid reason for it, so it's kind of hard to separate society from other things like that.

And talking therapies is sort of tend be all boil down to in terms of CBT, cognitive behavioural therapies at least, they try to coach people to think in ways which don't cause this sort of unhelpful outcome. So someone with depression, make them think in ways which don't result in them feeling so negative about themselves or the world or some of the anxiety talk about don't talk them into doing things or thinking in ways which do not trigger this nervous, anxious, fearful mindset. And it's you can argue it's kind of like reprogramming a computer, just thinking like this is a bad pathway. Do this one instead and do a workaround. And I guess the analogy I use in the book, which I'm sort of happy with and people have approved of, is that if you think of like your functioning mental state as your home and you travel to and from it to do what you're doing. So one day there's a bridge that leaves your house. That's how you normally achieve your good mental state, your regular mental state. Then one day it collapses. Could be because of trauma, because of general tear or just a flaw in the structure we didn't know about. So the bridge collapses while you're on the other side. So you need to get back to your home, your regular mental state, and you can't get there because the usual route is denied to you now. So the medical route, like using drugs, would be someone come along and build a new bridge, maybe not as good or maybe a pontoon or maybe it's just the scaffolding or a big plank or something. But you can get you there. It's not perfect and it's bit more treacherous. But that also involves you just there waiting for that to happen when you're outside cold and wet. Whereas talking therapy would be more like someone come along and say, OK, so you can't get back to your house. I've got a spare pair of boots. I got a map and a compass. Let's find another way around. And so they're going to go downstream, see if you can find another way across and they sort of help you to find another route to your destination, which is your healthy, functioning, functional mental state. Ideally, you use both of these. So this person fixing the bridge, while I'm going to find out way around. Between us, we will get back eventually. And that's why combined therapies tend to be the most effective overall, because you're taking two bites of the cherry. You've got double the chance. And the brain's been helped in two different ways, at least two. And that's always going to be more helpful, I suppose.

SR: You touched on this a bit with your wedding metaphor, so something that I wonder about anxiety disorders is that therw are often things going on in the world which are a genuine cause of anxiety, the emotion. So, anxiousness. Like climate change, or I suppose right now the pandemic going on. So there's a lot of people who would reasonably be feeling anxious about that. And so I sort of think, I don't know if this is correct, but I sort of think of an anxiety disorder is when you're feeling a lot of anxiety for something that's sort of unwarranted, that's something that doesn't really require that level of anxiety. So where's the line between feeling anxiety all the time over something that's real and out there? Is that like a disorder or does it have to be something that's not, you know, feeling anxiety, the things that are actually going to going to hurt you?

DB: Yeah, you've got it spot on there. That's anxiety disorders are normally recognised by the anxious response being disproportionate to what the source is. If someone's worried about climate change, and that's obviously something big and massively important that we should be worried about doing is an existential issue. To be worried about that is logical. So if you can't be anxious about climate change for five years, and I imagine Greta Thunberg has been, then yes. She's not got a disorder. She's just got a logical perspective on what's going on. But I guess it's a case of if you're anxious about climate change, the point where you're in your room, sort of huddled in the pillow, just constantly in the foetal position, cringing, shivering about the possibility of climate change.

That would be a disproportionate response because, yes, it's right to be anxious about it. But this is debilitatingly anxious about something that's very much a long term thing. You're going to walk out your front door and be hit in the face by climate change because it's not a thing that can do that. And I think that's where a lot of the distinction comes in. Yes, you should be anxious about this thing, but should you be this anxious about it? But that's also where like the... Diagnosising these things is really tricky. It's not like it's some one bullet point, you go, right, these three things, you're anxious now. Well done. Have a certificate or whatever. It's really quite marked in that it's so nebulous. Like this person. You can just have an anxious personality, you can be someone who is constantly worried about stuff. And that's not a disorder, that's your default state of being. Whereas someone else who is far more upbeat and far more chilled, if they became like that person, then that would maybe suggest an anxiety disorder because it's atypical for them. And there's been some interesting data which shows that during the pandemic and the lockdown, you'd expect people with depression and anxiety to have worse problems because there's more to worry about, more to be depressed about.

But what data there is suggests that if anything, these sort of plateaued. There's been no obvious increase in some people reported a lessening of their symptoms if they had pre-existing conditions. And it does sort of make sense in a way that say, if you're anxious about things which aren't there, which haven't happened, then a pandemic hits. That's sort of justifies your anxiety. Like people were worried the worst was going to happen. And then it does happen, they think, oh I wasn't unwell. I'm just rational. I was correct. And that can be oddly reassuring. It can be a de-stressor because I think when the worst has happened, there's nothing to worry about anymore, I guess.

You know, it does take... Before my father passed away, I was like hyper stressed for weeks on end and afterwards I wasn't stressed, I was grieving. It was the impact. But it was not as fraught because, you know, the worst happened. And I'm never going to say that's a good thing. But it was a very different way of, you know, it was very different emotional experience in that respect. And that's going to be something which obviously will manifest in a lot of different people. It's how proportionate it is. Anxiety disorders are so wide-ranging as well. PTSD is an anxiety disorder, but so is generalised anxiety disorder. Generalised anxiety disorder say it has no specific cause for the anxiety you're feeling. PTSD has a very obvious cause for the anxiety problems you're feeling, because this is the one major traumatic event which caused this to happen. But they both have anxiety disorders because symptomatically they have similar properties and seem to affect us in similar ways in the brain. But even like low level things like phobias, one of the more common anxiety disorders like arachnophobia is a very well known phobia. And a lot of people don't like spiders, but arachnophobia, if you are actually really terrified of them, I think the most perhaps frustrating part of it is for people with that, they know that it's not logical. You can tell them all you want. Don't be afraid of that spider. It's like the size of a two pence coin on the other side of the room. It's not going to hurt you. On a logical level, people, arachnophobia will know that. But the fact is that they don't react like that because the more fundamental subconscious part of their brain which deals with that, they're they're in control. So they think spider, scream, jump, run. They fire up the fight or flight response, whether you like it or not. And you have this extreme panic reaction, which is illogical, but that doesn't stop it. And so what happens with anxiety disorders, it's like the response is disproportionate or unwarranted to what the trigger is, if there is one. Sometimes they don't have a trigger. Like, panic disorder is a real thing like that in that there's no obvious cause for these panic attacks. And that's why they're so debilitating and so problematic. You can't anticipate that, you can't do anything about them. And I address this in the book, too. Some evidence suggests that the panic attacks are normally caused by novel stimuli. So it literally has to be something unexpected which causes it, and therefore you can't do anything about it. And they become so problematic because there's no real workaround outside of therapy and things. So, yeah, so you're right in that it's going to be something people anxiety all the time. But when it's doing when the anxiety has no obvious cause or is way more than the cause warrants, that's when you think, OK, that's not meant to be happening.

SR: That was Dean Burnett, author of Psycho-logical. His book is out now. Thank you for listening to this episode of the Science Focus Podcast. The January issue of BBC Science Focus Magazine is out now. Also in this issue, we explore the greatest mysteries of the universe. Dr Michael Mosley says his top tips for keeping your blood pressure on track. And as always, our panel of experts answering your questions. Of course, there's much more inside and on

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