Hot and bothered

Sana Qadar: Just a quick note this episode briefly touches on the topic of suicide. Take care. We're listening.

News anchor: For Sunny Thursday, with an expected maximum of 40 degrees... Frighteningly hot conditions over much of the continent in the coming weeks... To get even hotter, the Bureau of Meteorology.

Sana Qadar: 2023 is set to be the hottest year on record, and that's saying something with the.

News anchor: Warmest ten years on record all happening since 2005.

Sana Qadar: And with the Bureau of Meteorology also declaring an El Nino in Australia, we're likely in for a long, hot summer.

News anchor: It's also prompted health warnings.

Sana Qadar: Now, a lot of the reporting on the health impacts of climate change and heatwaves tends to focus on physical health

News anchor: ...People need to take care of themselves and stay hydrated.

Sana Qadar: But what about our mental health? And I don't mean just in terms of the distress and grief we might feel watching our planet get hotter and hotter. I'm talking about the more immediate effects on our emotions, our coping abilities, and our behaviour.

Dr Clare Skinner: For me, the hardest day in the emergency department is actually a hot, windy day. I'm really worried about what I'm going to see.

Dr Laurence Wainwright: A growing body of evidence has shown very clearly that extreme heat presents a host of challenges for those living with psychiatric conditions, but also for the mental health of the general population overall.

Dr Clare Skinner: And I do feel that on a really hot, windy day, you will see more people who are anxious, feeling suicidal and, you know, have psychosis.

Professor Craig Anderson: Rapid global warming is in fact already increasing violent behaviour.

Sana Qadar: This is All in the Mind. I'm Sana Qadar. Why does the heat have these effects and are we all at risk?

Professor Craig Anderson: Nobody actually kills a person just because they're hot. But you go back to this risk factor kind of approach under certain circumstances. Yeah, it does have an influence.

Sana Qadar: We're going to figure out what happens in our brains and bodies during hotter temperatures that can leave us more prone to violence or worsen certain psychiatric conditions.

Dr Laurence Wainwright: There's quite a few studies that point to potentially extreme heat acting as a switch into a depressive phase.

Sana Qadar: So today, how heat waves impact our brains and our behaviour.

Dr Clare Skinner: So for me, the hardest day in the emergency department is actually a hot, windy day because everyone's just really hot and bothered and people are very unsettled by the noise of the wind.

Sana Qadar: This is Dr Clare Skinner, and she's been working in emergency departments for the last 20 years.

Dr Clare Skinner: I am president of the Australasian College for Emergency Medicine, and I work clinically as a specialist emergency physician in Sydney.

Sana Qadar: And on a hot, windy day, not only will she be dealing with physical problems, bringing people in.

Dr Clare Skinner: Like kidney stones or gout that are caused by dehydration, I'm going to see people who are fainting.

Sana Qadar: She'll be dealing with a variety of mental health conditions, too.

Dr Clare Skinner: You know, people who have thought disorder, people who are feeling really anxious and stressed, feeling suicidal and, you know, have psychosis because it's just really hard to settle yourself emotionally when it's really hot and when the wind's whistling in your ears and leaves are flying past and rushing into your face, and you've got sand in your eyes. So I think for me, a hot, windy day is definitely a red flag for a very difficult shift in an emergency department.

Sana Qadar: It's because that kind of weather, she says, can act like a tipping point.

Dr Clare Skinner: You know, if someone's life is really difficult, then that that weather makes everything more difficult. So if they're just coping, that weather might be the thing that tips them over the edge and look, it's hard to reach out to people on one of those extreme weather days. You're not naturally bumping into people at the shops or having gathering things. You're sort of a little bit stuck at home, so emotionally they're really difficult to.

Sana Qadar: This might be Doctor Skinner's personal experience working in EDs on hot days, but it reflects what the research shows about the impact of heat on mental illness.

Dr Laurence Wainwright: So for those groups in Australia, probably about 15% of the population living with whether it be a mood disorder, an anxiety disorder or similar, heat waves can exacerbate existing conditions. They can they can act as a switch into a certain phase of of a condition such as a mania in in bipolar disorder.

Sana Qadar: This is Laurence Wainwright. He's a lecturer and course director of the master's program in Sustainability, Enterprise and environment at the University of Oxford. He's also a researcher at the Oxford Precision Psychiatry Laboratory.

Dr Laurence Wainwright: I'm very much an interdisciplinary researcher.

Sana Qadar: He says there are a number of factors that help explain why hotter temperatures can worsen certain mental illnesses. One is as basic but fundamental as sleep.

Dr Laurence Wainwright: Which is such an important factor in good mental health can be obviously affected. We all know what it's like when when it's hot and we're sweaty and we can't sleep at night. The body's dehydrated. Um, resources are expended elsewhere.

Sana Qadar: Then there's also the way heat affects the medications people with certain mental illnesses might be taking.

Dr Laurence Wainwright: The side effects of many medications are worsens by warmer temperatures, the efficacy, how well the medications actually work, and their mechanisms of action can be slightly reduced by hotter weather, particularly when it gets very hot.

Sana Qadar: And so here is what all of that means in a condition like schizophrenia.

Dr Laurence Wainwright: So there's a positive and significant correlation between temperature and exacerbation of symptoms in in schizophrenia. Unfortunately during heatwaves the risk of mortality doubles essentially which is which is very concerning. In schizophrenia there's a class of medication used called the antipsychotics. And these medications are particularly impacted by heat in the sense that these medications can change our perceptions of thirst. So the body has a really good way of telling us when we're when we're thirsty. And these medications are interfering with that function so the body can overheat. So schizophrenia is is a very serious and severe mental illness. And during heat unfortunately we see worsening in in morbidity and and mortality for these individuals.

Sana Qadar: That's worrying because schizophrenia affects about one in every 100 Australians. But more common is bipolar disorder which affects about one in every 50 Australians.

Dr Laurence Wainwright: So this is a fascinating condition, Bipolar. Unfortunately there's strong evidence during extreme heat for a rise in in hospital admissions for a switch into a certain phase of the condition. So people with bipolar disorder are either in about half the time in an asymptomatic phase. So nothing is happening. Mood is normal. And then there's obviously phases where the rest of the time is in bipolar two primarily spent in a in a depressive phase.

Sana Qadar: But he can lead to a switch into mania for bipolar one and hypomania for bipolar two

Dr Laurence Wainwright: Which is a lower version of mania in bipolar two. Gordon Parker's work in Australia suggests that the heat and humidity are two factors associated with a switch into into mania. Another problem with bipolar, of course, is the medications used. As I alluded to before, lamotrigine and lithium, and also the antipsychotic class, which is also used in schizophrenia. And again, these are changing perceptions of thirst. They're making it more likely for the body to be hydrated. The side effects are worsened. We're sweating more. We're finding it harder to sleep at night. So bipolar disorder is a very serious mental health condition, and it seems that extreme heat exacerbates many aspects of this condition.

Sana Qadar: The last condition I wanted to ask Laurence about was depression, because that is one of the most common of all, affecting about one in every six Australians.

Dr Laurence Wainwright: Yeah. So it's really, really interesting. There is um, a mixed body of, of evidence here, but there's quite a few studies that point to worsening of symptoms, potentially extreme heat acting as a switch into a depressive phase. So someone who is currently asymptomatic, um, extreme heat, particularly over many days, could theoretically and in practice act as a switch into a into a depressive phase of the condition.

Sana Qadar: So the opposite of what can happen in bipolar disorder.

Dr Laurence Wainwright: What seems to be at play here. And with all of these factors, we're looking at complex, nuanced interactions between variables, whether it be the nature of the condition itself, socioeconomic status, you know, even things like, does someone have access to air conditioning? People are not getting enough sleep for many nights in a row. And we know that that's a risk factor for, um, for mood disorders such as depression. The medications they're taking, psychological behavioural factors, all of these subtle, nuanced factors interacting in, in in feedback loops that we don't fully understand how and why. So, yes, um, a host of a host of problems there for individuals with with major depressive disorder.

Sana Qadar: And the crux of the issue is all of this can lead to more deaths. Tell me a bit about the literature on suicide and heatwaves. What's the what's the relationship there?

Dr Laurence Wainwright: Yeah. So unfortunately, there is an extremely clear body of evidence that rates of suicide attempts and completion go up as it gets hotter. Unfortunately, this is also the case for violent suicide, such as jumping in front of trains, jumping from high, high places. Um, a study in the US in 2018 found a 1 to 2% increase in suicide rates associated with a one degree increase in mean monthly temperature. So these are very slight differences. Let's say here in Oxford we have an average monthly temperature. But the Sydney is a better example. If we have an average monthly temperature of of 24 Celsius in November, and that goes up by one degree Celsius as a result of climate change, which which it will then rates of suicide go up by 1 to 2%. Risk of suicide doubles if we're looking at, say, a temperature of 32°C versus 22. So very, very strong evidence here. Perhaps the most overwhelming evidence for this. And I spoke recently at a House of Commons inquiry here into the problematic issues heat presents for the for the UK going, going forward. And this was one of the, the findings that I really, really emphasised.

Sana Qadar: Yeah that's incredible. Like do we know why this link is so clear and why it's there?

Dr Laurence Wainwright: Yeah. The short answer is we don't we don't fully understand what's going on here. It seems to be a host to a very, very complex interactions. Again, between these psychological behavioural factors support systems in place, the heat itself. So these factors seem to combine together and sadly result in in higher rates of suicide.

Sana Qadar: How much does geography play a role in all of this? Because obviously there are parts of the world that are hotter than others. I mean, here in Australia it can get extremely hot. So as a person who lives near the equator, for example, going to have a different response to increasing heat than someone in the UK?

Dr Laurence Wainwright: Yeah. So it does it does matter. And you know, on an outright level, um, you know, we would expect that that rates of suicide in a very warm area of, of Australia would be higher than the United Kingdom. Yeah. But the other thing we know is that humans are reasonably good at adapting to, to temperatures. And in this country, for instance, you know, society is not set up to deal with extreme heat. All of those support structures, infrastructure, health systems are not designed for what we had last year when we had a 40 degree day and we had a very, very serious heat wave across the UK, which killed 3500 people and across Europe killed 60,000 people. So humans are, are, are adaptable. And if one was to move, you know, move from the UK to Australia as many people do, you know, it takes a bit of time to acclimatise and adjust, but it's it's perfectly possible.

Sana Qadar: But as global temperatures rise, Laurence says there is also a limit to how much humans can adapt. And so just putting mental illness aside for a moment, for people who don't have an existing mental health condition, the heat can still impact their mental health, right?

Dr Laurence Wainwright: Yes, very, very much so. The first thing would be so we know that, as I said, 80% of people who take their own lives generally have an underlying mental health condition. But for the 20% who don't, we also see here an increase in in rates of suicide and suicide completion, uh, a decline in cognitive function. So processing speed, attention, memory and associated productivity here, um, increased levels of irritability, increased levels of anxiety and stress. So if we sort of cast a big net over all of that and we think about mental health as being this, this broad concept around, you know, overall psychological well-being being and the ability of an individual to sort of manifest their their best, most productive self in the world. Um, we see that extreme heat presents a range of challenges.

Sana Qadar: Unfortunately, the situation just gets more and more grim. Aside from the impact of hot temperatures on our mental health, research suggests heat impacts our behaviour and not in a positive way.

Professor Craig Anderson: A lot of the research shows that when people are uncomfortably hot, that leads to things like poor decision making, it increases the likelihood of impulsive behaviours and that includes a lot of aggressive behaviours.

Sana Qadar: This is Craig Anderson.

Professor Craig Anderson: I am a distinguished professor of psychology at Iowa State University.

Sana Qadar: He says rising temperatures have both short term effects on behaviour as well as long term effects. But let's start with short term overall.

Professor Craig Anderson: You know, in terms of what we think of as as short term effects, we typically use the label irritability to cover a broad range of phenomenon. There's evidence very strong evidence that that increase in irritability plays out in terms of increases in aggressive and violent behaviour, so hotter days tend to lead to increases in homicide, intimate partner violence, sexual violence, primarily rape. So for example, in the US, violent crime rates, particularly homicide and assault, tend to increase in the summer months. Furthermore, that increase in violent crime is unique in that non-violent crimes don't show that same pattern.

Sana Qadar: Ah, right. So people aren't committing more fraud on hot days, but they're hurting other people on hot days.

Professor Craig Anderson: Or burglaries or auto theft, for example. Those are, you know, some of the crimes that, you know, FBI reports. That's where a lot of these data come from.

Sana Qadar: Right, so that's really interesting. So it's very specifically like interpersonal aggression and sort of antisocial behaviour that happens.

Professor Craig Anderson: Yes. What we would call social conflicts. It is also the case that years in which there are more hot days, as defined by the National Oceanic and Atmospheric Administration, actually, you know, has a definition. I think it's 92 degrees.

Sana Qadar: That would be in Celsius 33 degrees.

Professor Craig Anderson: Summers have more hot days in them, tend to yield again, higher violent crime rates than summers with fewer hot days in them.

Sana Qadar: Craig says that's important because that rules out a lot of alternative explanations for what might be going on here. The idea that in summertime people are on holiday so they have time to commit crime or they're drinking more beer. That is the case in cooler summers, too. And yet violent crime increases more in hotter summers. You can also break down the impact of heat on violence into time periods.

Professor Craig Anderson: You have to take into account that there are going to be time of day effects, but then you can ask okay within a given period of time, is it the case that hotter periods of time, say midnight to 3 a.m.? The hotter midnight to 3 a.m. time periods tend to lead to higher violent crime rates than the cooler midnight to 3 a.m. time periods. And it turns out the answer is yes.

Sana Qadar: And how is this for a scary convergence of these trends? Not only is 2023 shaping up to be the hottest year on record globally, only this week another record was broken.

News anchor: The Washington Post says 2023 has already become the worst year for mass shooting fatalities in the US.

Sana Qadar: There have been 38 mass shootings in the states this year. The previous record was 36. Whether that's a coincidence or not, it's probably too early to say, but it's a troubling sign. On top of looking at crime rates, Professor Craig Anderson has also conducted research in lab settings as a way to understand how people think and feel about others when they're all hot and bothered.

Professor Craig Anderson: In some of our research, for example, we've found that people just watching videotapes of two people having an interaction. We found that when they view such interactions under uncomfortably hot conditions, they tend to perceive more hostility and aggression in that interaction. Then people who watch the same videos but under comfortable conditions. So in other words, it makes people's perceptions somewhat biased in a sort of hostile direction. And of course, when you perceive hostility in other people, that's one of the factors that leads people to aggressive behaviour themselves.

Sana Qadar: Do you think people are generally aware of this kind of thing, or are people shocked when you talk about this?

Professor Craig Anderson: Yeah I get two kinds of reactions, kind of from the more general public. You know, one is, oh yeah, we knew this all along, so who cares? Uh, two absolute denial. Uh, that can't possibly be true. Nobody kills a person because they're hot. And at one level, that denial is true in that no, nobody actually kills a person just because they're hot. But you go back to this risk factor kind of approach under certain circumstances. You know, the risk factor of being more irritable because of the temperature that you're in. Yeah, it does have an influence. Again, if you have a huge enough sample sizes to detect modestly small effect sizes.

Sana Qadar: Okay. So that covers off some of the direct or short terms impacts of heat on violence. But Craig is also interested in the indirect or long term impacts.

Professor Craig Anderson: By indirect effects, we mean effects of rapid global warming on things like fail crops, natural disasters, economic instability that's caused by rapid global warming, poverty, and and a key concept that's called eco migration, where groups of people are forced to migrate because if you can't grow crops, you know, you've got to you've got to leave.

Sana Qadar: And Craig says one of the less obvious ways all of that can lead to more violence over time is through poor nutrition.

Professor Craig Anderson: Researchers, primarily psychologists. But other research domains have also looked into what are the the environmental factors that lead, say, a newborn, to become a violence prone adult. And we know a lot about that. Sociologists, criminologists, political science. I mean, there are a lot of other groups that have been doing research on this. So we know, for example, that poor prenatal nutrition increases the likelihood that that child will eventually grow up to be violence prone adult. The same thing is true for postnatal nutrition. If that child is not well nourished, the brain can't develop properly, and that means that that individual is going to experience much more failure in terms of, you know, ability to navigate life and to become a productive citizen. And that leads to criminality. From the climate change perspective, the proportion of the world's population that is being subjected to these known risk factors is increasing because of rapid global warming.

Sana Qadar: So when you think about the future, the next ten, 20, 50 years, what do you see?

Professor Craig Anderson: That's a very good question. And, you know, we've already seen increases in intergroup violent conflict that are related to the amount of global warming that's already happened.

Sana Qadar: Like what?

Dr Laurence Wainwright: Well, let me give you one specific example has to do with Syria, the Syrian civil war.

News anchor: Millions of refugees forced to flee their homes in Syria because of a violent civil war. Y

Professor Craig Anderson: You know the outbreak of it came fairly soon after an unprecedented drought in the food production regions of Syria, which in turn led to mass migrations from these agricultural areas to cities. As families, you know, were seeking ways to earn money so that they could feed their families. And unfortunately, for a variety of reasons, not all of which I understand because I'm not a political scientist.

Sana Qadar: Sure.

Professor Craig Anderson: Uh, but the Syrian government was unable to handle, you know, unable or unwilling or, you know, however you want to frame it was unable to handle this migration, which in turn then leads to and did in fact lead to increases in civil disorder. Now, that's not to say that had there not been other factors, sort of war inducing factors in place, right. The rapid climate change itself doesn't necessarily produce that kind of civil war, but it is one of the risk factors. And and when there are a bunch of other risk factors in place, such as an unstable government, governments that are not terribly wealthy and so can't absorb the costs of such disasters, the rapid global warming adds more pressure becomes another risk factor for such things happening.

Sana Qadar: So do you basically see a more violent future for the world?

Professor Craig Anderson: Yes.

Sana Qadar: Gosh.

Professor Craig Anderson: Yes, I do see a more violent future. One of the things, you know, as a social psychologist, one of the things we know that increases intergroup hostility is whenever there is stress on, say, the current economic system of a given country. Uh, and it doesn't actually even have to be real. I mean, whenever there's perceived stress, you tend to see a movement towards preferring one's in-group over outgroups. And very often that's based on racial lines, can be based on religion, where, you know, you can see us versus them kind of thinking. And that in general is consistent with what we usually think of as a right wing or authoritarian kind of view of the world. That, of course, has led to increasing support for authoritarian regimes, including in the United States, but other countries as well. The eco migration crisis has led to many Western European countries the rise of anti-immigrant policies. And so, again, unless people are really educated about what's really going on here, what you're likely to see is further movement towards more authoritarian rule, more protect ourselves against the outsiders. And of course, if you prevent huge portions of the population who are now in unliveable circumstances, if you don't provide for them in some way, they're going to become more susceptible to terrorist organisations and, you know, resulting, whether it be civil wars and, but other kinds of group conflict. So, yeah, the future can look pretty bleak.

Sana Qadar: I mean, we're in a scary present. We've got a bleak, scary looking future ahead of us. Is there anything to be hopeful for anything in the research or that you've done or elsewhere that you know that gives us something to be hopeful for, right?

Professor Craig Anderson: And that that is a very key question. In a sense, the the question also becomes, what can we do about this? We shouldn't see this as a case for, you know, building walls and digging in, you know, your trenches and keeping people out. We should see this as a global threat on the human species that can be met by the human species, by being smart.

Dr Laurence Wainwright: Yeah. I mean, I think sometimes going into these interviews, you know, academics get criticised for, for being quite doom and gloom.

Sana Qadar: This is Laurence Wainwright again from Oxford University. Remember, he researches the impact of heat on mental illness.

Dr Laurence Wainwright: You know, But I think we have an obligation to present the evidence. And the evidence is becoming very, very clear that that the writing, the writing is on the wall. Y

Professor Craig Anderson: You know there are certainly are attempts, of course, at the moment they're falling very far short, both in terms of just global warming itself and greenhouse gases, but also in terms of these psychological, these social interaction. You know, we really haven't done much on those dimensions, but we could. In that sense, I'm optimistic that we can still solve this in a non-violent way.

Dr Laurence Wainwright: So yes, I'd say that I'm very concerned. But it's really important also to emphasise that for the 15% of Australians living with a mental health condition, these problems can be avoided. There are support structures in place, you know, we do have access to to cooling facilities. The medications still work in most cases, you know, extremely well. The side effects can be can be abated with careful planning. So this is this is a matter of, you know, there are people who fall through the net and these are the ones who make up the numbers. But for most people, these these challenges can be prevented with careful with careful planning.

Sana Qadar: And since the emergency department is where many people who are suffering the effects of heat will end up, whether that's because of physical problems, mental illness, or violence. Here's a final message from Doctor Claire Skinner.

Dr Clare Skinner: We can't just be the ambulance at the end of the road here. These are real people and real, real communities, so we need to urgently address the causative factors of climate change. And we also need to make sure as our weather gets more extreme, that we're adequately designing and resourcing our health and social care systems to be able to deal with more and more people feeling the impacts of extreme weather and climate change.

Sana Qadar: That is Doctor Claire Skinner, a specialist emergency physician based in Sydney. You also heard from Craig Anderson, distinguished professor of psychology at Iowa State University, as well as Doctor Laurence Wainwright. He's a departmental lecturer and course director of the master's program in Sustainability, enterprise and Environments at Oxford University. And an update since we first put this episode together, scientists at Copernicus, that's the EU climate monitoring program, have declared 2023 is in fact, the hottest year on record. It's not just on track to be the hottest, it is the hottest. I wish this episode wasn't so full of bad news, but this is the reality of where we're at with climate change, and I wish it wasn't so. That is it for All in the Mind this week, thanks to producers Fiona Pepper and Rose Kerr and sound engineer Emrys Cronin. I'm Sana Qadar, thank you for listening. I'll catch you next time.