Stressed out?

Rudolphina: Mr Nater, stress is central to your everyday research. For example, you are developing methods for measuring stress. How do you induce stress in your study participants and how can you measure it?

Urs Nater: There is a wide range of stressors in humans that we can use in the lab. One of the best methods for – and this may sound mean – stressing our study participants is the Trier Social Stress Test. It combines a mock job interview before a selection committee comprising two to three interviewers with a complex mental arithmetic task. The committee does not show any socially acceptable response, such as smiling or nodding. This social situation very reliably triggers a stress response, especially when participants have to solve an arithmetic problem. 

During this stress test, we measure a variety of factors which are known to reflect the stress response. These range from the heart rate, heart rate variability and electrochemical skin conductance to hormones as well as immunological parameters, which we usually measure in the participants’ blood or saliva.

Rudolphina: The physical response to stress is a natural process which often helps us cope with difficult situations. Could you briefly explain what happens in the body when we experience stress?

Urs Nater: We absolutely need this mechanism to be able to cope with challenges and threats in the first place. In the past, our physical stress response enabled us to flee or fight, so it needs to kick in extremely quickly, which it does thanks to the autonomic nervous system. The parasympathetic nervous system, which lets our body rest, reduces its activity and activates the sympathetic nervous system, which triggers the fight-or-flight response. 

This is a very immediate stress response. To efficiently cope with a stressful situation, hormones additionally modulate the acute stress response and ensure that our body is provided with everything it needs. For example, by ensuring a fast supply with immune cells in the event of an injury.

Rudolphina: This physical stress response helps us cope with exceptional situations, such as a threat or particular challenges. What happens when you experience stress very often and regularly, for example, as a doctor in the emergency room?

Urs Nater: Exposure to frequent stress can cause a kind of ‘wear and tear’ in the stress-relevant systems. We call this the allostatic load. It minimises an organism’s ability to adequately cope with stress and usually has an impact on physical and often also on mental health. We conduct stress tests to for check this. People whose stress response is not functioning properly may overreact to stress or are desensitised to it.

Rudolphina: As a member of the research platform The Stress of Life, you are investigating stress responses in everyday life, beyond controlled laboratory conditions. How does this work? Are you doing research in hospitals or editorial offices?

Urs Nater: We are not that interested in the settings that might cause stress. We assume that everybody, regardless of their job, is able to experience stress – some more than others. From a strictly quantitative perspective as well as qualitatively speaking, the stress they experience is exactly the same. Of course, I am not referring to extreme situations such as a lethal threat, that is not a situation the average person is commonly confronted with. 

But at the end of the day, it all depends on the individual. What is their predisposition? How do they assess their own resources for coping with stress? All of this determines the level of stress we experience in certain situations.

Rudolphina: How can you measure the level of stress in the everyday lives of study participants? It is not a laboratory setting, after all.

Urs Nater: The participants in our studies use an app in which they independently answer questions over the course of the study. There are fixed times every few hours per day at which they have to assess certain parameters, depending on the question. For example, they have to evaluate how they slept or how stressed they are currently feeling. If they experience stress in the moment, they have to answer questions about the stressor. In addition, we ask them to always share their experience in the app when they have acute stress. 

Such measurements in day-to-day life are called Ecological Momentary Assessment (EMA). With the use of the EMA we have the advantage of being able to avoid memory bias, i.e. false memories. Study participants also independently collect saliva samples at times specified in the app. We then analyse these samples in the lab to check for stress hormones, among other parameters.

Rudolphina: Can you tell us of an interesting study on everyday stress that you conducted?

Urs Nater: We are particularly interested in the interactions between stress and certain physical complaints. In one study, we investigated the connection between stress and physical fatigue. We found that the more stress participants experienced, the higher their level of fatigue, and in turn, a higher level of fatigue increased the level of stress. 

In a current study, for example, we are investigating premenstrual symptoms such as irritability or mood swings, as well as the physical complaints that accompany them. Our research question is: What influence does stress have on these complaints? And conversely: Do premenstrual complaints influence the experience of stress afterwards?

Rudolphina: As part of a particularly exciting project, you are also exploring stress management and its impact on health. You are Head of the ‘Music and Health Lab’, where you and your team are investigating the positive effects of music on mind and body – and on the stress levels.

Urs Nater: We assume that music can have positive health effects, and especially on reducing the level of stress. The key question in all our studies in the lab is how we can make use of music to reduce stress. We found that the level of stress significantly reduces after only around 20 minutes of listening to music in people who develop a habit of listening to music in stressful situations. It has a noticeable effect, especially when you listen to music with the intention of reducing stress. Of course, it also depends on the intensity of the stressor. If the stressor is very intense, music is not powerful enough.

Rudolphina: Do you also listen to music to reduce stress? What does a stress researcher do to relax?

Urs Nater: Well, I am obviously very privileged as a professor – the Rector is of course interested in my research, but he does not call to give me assignments, so I am very self-determined in my research. And I have to consider this when answering your question. My situation allows me to say ‘no’ to things that would overwhelm me. For example, I do not work on the weekends, I do not answer e-mails after 20:00, and when I am on holiday, I am offline, or at least I do not check my Outlook. I can thus control potential stressors to a certain extent. 

At the same time, I am aware that a cashier in the supermarket, for example, does not have these options. They have to sit at the cashier’s desk at 7:40 in the morning and cannot say ‘no, I will not do this now’. I am fully aware of that. In principle, it is important to develop a habit that allows you to alleviate stress in some way. This can mean anything. In my case it is martial arts; others say that yoga or listening to music helps them. The better you are at reaching a state of relaxation, the more you learn that you are capable of it – this empowers you to cope with stressors.

Rudolphina: You have mentioned everyday stressors and how to cope with them, but what about exceptional situations such as exams, job interviews or public speaking?

Urs Nater: This is a topic that we also discuss with participants in our stress interventions. We try to identify what they can do in stressful moments to reduce the level of stress. In this context it is important to challenge yourself. For example, when I am stressed before a presentation, I like to ask myself what the worst thing that could happen is. I will most likely not have a heart attack while I am on the podium and it is also unlikely that the audience will laugh at me – after all, I was invited because the audience wants to hear about my research. These are the strategies we try to convey to participants in our interventions – strategies they can practise and acquire.

Rudolphina: Thank you very much for the interview.