The major earthquake in Turkey and Syria last week killed tens of thousands of people and caused tens of billions of dollars in damage. It is also taking a toll on survivors’ mental health.

Research has confirmed that natural hazards such as this magnitude 7.8 temblor lead to acute trauma and an increased risk for chronic conditions such as anxiety and depression in survivors. Ben Beaglehole is a psychiatrist and senior lecturer in the department of psychological medicine at the University of Otago, Christchurch, in New Zealand. Beaglehole and his colleagues have studied the mental health impacts of New Zealand’s 2010–2011 Canterbury earthquakes as part of a 40-plus-year study  measuring the health and development of a cohort of more than 1,200 people born in the late 1970s. They found an increase in the rates of anxiety disorder, post-traumatic stress disorder and nicotine dependence one year after the quakes, and this increase was correlated with greater exposure to the events. In other words, the closer a person was to the quakes’ most severe effects, the more likely they were to have a mental health disorder.

Scientific American spoke with Beaglehole about how deadly earthquakes and their aftermath affect mental health, the role of socioeconomic factors and cultural setting, and the factors that increase resilience and post-traumatic growth.

[An edited transcript of the interview follows.]

How do you study these kinds of natural hazards? And what do we know about past disasters that could help inform the response to the recent earthquake in Turkey and Syria?

The reason I started doing disaster research was because Christchurch, New Zealand, [and nearby areas of the surrounding region of Canterbury] had a severe series of earthquakes starting in 2010 and continuing through 2011, and I was a clinical psychiatrist at the time, with some observations about what was happening from our practice. That got me interested in the evidence relating to disasters and mental health.

In terms of how to how to study these things, first, you need disasters to happen. Some research is very reactive: a disaster happens, and then people decide they need to measure the impact, and they’ll do a survey. But there are things that can improve the quality of your research. One is thinking very carefully about “When is it important to measure the effects?” Ideally, you don’t want to measure the effects as a one-off. Probably there’s little use in measuring the effects a week after a major disaster. Measuring the impacts over time is important. If you can, it’s nice to be able to compare any measurements with predisaster measurements because it’s easy to assume that, for example, the rates of depression you’re seeing are because of the earthquake. But if there were high rates before the disaster, that’s a confounding factor.

Often people don’t think about doing this research until after the disaster, but if there is a baseline measurement, that’s important. If you don’t have a baseline measurement, you can manage that by comparing your findings with findings in a less exposed area—an area with lesser earthquake effects or no earthquake effects. And then the final thing to decide is which population you’re going to measure effects in. It’s easy to find a bunch of people that want to tell their story, but do they represent the population of interest? These things are important: When are you going to measure the effects? Who are you going to measure them for? And what are you going to compare any findings with?

You’ve studied the psychological effects of the 2010 – 2011 Canterbury earthquakes in New Zealand. What did you find?

One of the papers I’ve written is based on data from the Christchurch Health and Development Study, which is a birth cohort study that’s been going on for more than 40 years. [Editor’s Note: In a birth cohort study, researchers follow a group of people born in a certain period from infancy through adulthood.] [The researchers] had preearthquake measurements on multiple occasions, and they could also look at other factors such as previous trauma exposure, sociodemographic factors, the impact of prior mental illness. We can take those factors into account when we are trying to estimate what the impacts of the Canterbury earthquakes were on mental health. If you don’t take those factors into account, you come up with higher estimates than if you do, because some people are both more likely to experience mental health problems and more likely to have bad earthquake experiences.

Which people are most at risk of trauma and other mental health problems after a severe earthquake?

When you think of an earthquake’s effects, you may think earthquakes have an indiscriminate or uniform effect on everybody. But in reality, if you live in a poor part of town, your buildings are more likely to be destroyed. And you’re also more likely to have other factors that might increase your risk of depression. So it can look like the earthquakes are causing more negative effects on mental health than they actually are if you don’t control for other factors.

What we know about trauma and mental health is that although there is the potential for people to grow through trauma, trauma is not recommended because it also causes negative effects. And those negative effects are that the traumas interact with risk factors to increase mental health problems following disasters.

How do the setting and local conditions where an earthquake takes place affect the likelihood of survivors suffering mental health effects?

If I could compare having an earthquake in Syria to having an earthquake in Christchurch, I suspect that Christchurch is the place to be. We have pretty good building codes here, so although some of our buildings collapsed and people lost lives, mostly, our buildings didn’t kill people. We have a lot of insurance—individual homeowners were mostly insured. We have a pretty intact health care system that is free. And we had the ability to offer extra support monetarily, with counseling, with physician visits, and so on. It’s not the shaking that is so important. It’s really everything [that happens during the recovery period]. Some of those things will be pretty tough in Syria in particular, but I can observe from afar in Turkey as well that there are some real issues with the buildings. You could compare that with Japan as another example of a country that experiences very major earthquakes, but they designed their buildings to not just keep people alive but also to keep being usable.

How can people attend to the very immediate trauma of experiencing an earthquake and losing loved ones, as well as the longer-term impacts of having the physical infrastructure of one’s city destroyed and not being able to receive ongoing medical care?

Maslow’s hierarchy of needs is quite relevant. The priorities are clean water and shelter and rescue. If there is a kind of psychiatric need right now, it’s psychological first aid, as opposed to treatment—really with a big focus on providing for social needs but perhaps just being reassuring, helping people get some sleep, and helping people connect and talk to loved ones rather than health professionals saying, “We need to provide cognitive-behavioral therapy” [a type of talk therapy used to treat mental health disorders].

Such aid doesn’t require experts to deliver. I think the idea of too many outside experts without local knowledge trying to impose themselves wouldn’t be the right thing. The enormity of physical repair that needs to happen is the priority. And any psychological support should be relatively low-key and supportive rather than trying to label illnesses and treat them at this point in time.

What qualities make a society more resilient to these kinds of traumas? And what factors make things worse?

The more trauma a society has gone through, the more likely people are to be experiencing mental health problems. And the more cohesive society is, the more protective that will be. I think the structure of a society is important: the ability to respond in a caring way requires a well-organized society.

We wrote a paper on post-traumatic growth following the Canterbury earthquakes. And the [Christchurch] Health and Development Study also has resulted in previous papers on post-traumatic stress that tried to use complicated mathematics to predict who grows through adversity and who experiences mental health problems. One of the factors that came out of that research was “peritraumatic distress”: At the time of the earthquakes, did you believe you were going to die? Or did you think that “this is just an earthquake, and I’m going to be fine”? That was one factor. And the other one was called “disruption distress”: How much of an issue did the earthquakes continue to have on your life in the days and months afterwards? Were you able to work, were you able to live normally, and so on? These factors predict post-traumatic stress. If you have a very difficult experience during and after an earthquake, you’re more likely to develop post-traumatic stress symptoms, but you are also more likely to grow through it—you’re likely to see positive development and new relationships and a new spiritual self. The large majority of people will be resilient. So although this is a devastating disaster, we shouldn’t assume that people will inevitably struggle with their mental health.

Out of the elements of the post-disaster effects is this idea of severity of experience or severity of exposure. In Christchurch, for example, the central city was most affected. If you were there, you would have seen people dying, and you’d have seen buildings collapsing. But if you lived in the west part of town—the wealthier part—buildings were fine. Infrastructure was fine. The exposure there was much less; the east part of town was more damaged. So greater exposure does predict greater impacts. The media footage I’ve seen of the earthquakes in Syria and Turkey would appear to show widespread severe exposure, so there are going to be a lot of people more likely to have adverse effects.

How do people cope with survivor’s guilt—the guilt that they survived when so many around them did not?

That’s not really an area I know much about. But I think from a psychological point of view, people often transition through different phases of thinking in response to life events. You probably remember people talking about phases of grief, for example. My suspicion is survivor’s guilt might be a bit like that. You might have some disbelief; you might feel guilty; you might feel grateful. You probably have swirling emotions, not necessarily that well organized or proceeding in a regular way, and that will be something that you have to adapt to. If you get stuck feeling guilty, that might be an area that you would need to see a therapist about, potentially. But there will probably be a lot more bigger priorities.

Are there factors unique to Turkey and Syria that will shape the impact of the earthquake on people’s mental health?

Syria may feel very abandoned. That’s a part of the world that has had a very tough time in a civil war. And [people there] will be thinking, “Why is this happening to us?” In Turkey, at least, I think it’ll be a lot easier to respond, albeit still with the difficulties that we’ve seen in the media. But it’ll be even harder in Syria to get right.

It looks like there are going to be quite severe effects for some, despite the majority being resilient, given the extent of that disaster.