The placebo effect shows how strong the connection between body and mind is. In fact, this effect revolves around the expectations that someone has of a treatment. Andrea Evers is conducting pioneering research into how these expectations can be used in healthcare. Within NSMD, she leads Team Mind-Body Interface. "The fascinating thing about the placebo effect is that it can even have physiological impact."

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When you hear Andrea Evers, Professor of Health Psychology at Leiden University, speaking in a talk show on TV or national radio, two things stand out. First of all, her perfect command of Dutch, with very rarely a mini-Germanism from her German mother tongue. But above all, the clarity with which she talks about her field. She explains complicated matters clearly and does not shy away from giving her opinion on social developments. This is where her motives come together: sharing knowledge and building bridges. "I see myself as an ambassador for science; I think it's important that people understand why, for example, basic scientific research is important, what our field of study entails and what it can mean. That is why I respond to requests from the media, for example during the corona pandemic to talk about the impact of the measures on mental wellbeing." 

Award-winning bridge builder

The bridge-building is particularly evident in her role as project leader of 'Benefit for all', a project funded by the Dutch Heart Foundation in which healthcare organisations, private partners and scientists are jointly developing a lifestyle intervention for heart patients. Or the development of a VR tool to train doctors to communicate more effectively with patients. Or her Medical Delta professorship Healthy Society, with which she is connected to the universities in Leiden, Delft and Rotterdam with the aim of driving interdisciplinary research in the field of a healthy society. 
Her efforts to translate science to society did not go unnoticed. In 2019, she was awarded the ‘Stevinpremie’, the highest scientific award in the Netherlands for scientists who dedicate themselves to this. "Just when I myself had decided not to worry about it anymore. I realised that it is for others to judge and that it is not all in your hands whether society picks up scientific knowledge."

The role of trust in the placebo effect

Similarly, the insights she has generated about the placebo effect are not yet being applied in healthcare as much as she would like. In 2018, together with international scientists, she wrote a recommendation for healthcare providers, but changes, especially in healthcare, just don't happen as quickly. "The placebo effect is based on expectations that people have. You trust the doctor because you are conditioned to believe that he or she can make you better. When a doctor prescribes something and tells you about a medicine, he or she is communicating certain suggestions. That's a learning process, but it wouldn't work if you didn't trust that it can work." 

How doctors then talk about the drug's efficacy, or side effects, affects the outcome of treatment, scientific research shows. Too much knowledge of side effects increases the chances of actually experiencing them. If you have no confidence in a treatment, the chance that negative effects, such as more side effects, will occur is also greater; the nocebo effect. Evers and her group showed that the placebo effect can even have a physiological impact. "If you give people an anti-inflammatory for a few days together with a harmless but distinctive drink, after a few days the body also shows this immune response without the medicine, just by drinking the drink. It works, as it were, like the little bell with which Pavlov conditioned his dog. It is fascinating that the placebo effect can influence such biological outcomes, including the production of the hormone oxytocin.

On to less medication use

You could also use this principle to reduce the use of medication. Using some of the money from the Stevin prize, she is starting a pharmacological trial with dermatology patients to investigate this further. "You have to look carefully at which patients are suitable for such a study. They must not be too seriously ill and fluctuating medication must not have too serious consequences." These are very long-term studies, for which just preparing the research and obtaining ethical approval can take up to two years. "I use part of the Stevin grant for such expensive studies. I used to think that the pharmaceutical industry would probably also be very interested in this type of research, because it is ultimately about optimising the use of medication. But that was disappointing and at the same time it's not a bad thing, because as a scientist you mainly want to work independently."

Inspiring colleagues

But also: you want to workg with fun, inspiring colleagues. That's what attracted her to this gravitation project, in addition to NSMD's substantive questioning. "While studying clinical psychology at the University of Amsterdam, three of my current NSMD colleagues were there as PhD students or associate professors: Wiers, Kindt and Jansen. Through the Dutch-Flemish Experimental Psychopathology school (EPP), of which I have been a member since its foundation in 1995, you easily keep in touch with each other and it is very inspiring to work more closely together now, also with the people in my NSMD team." 

Among other things, the Mind-Body Interface team investigates the role of expectations in the network of people with various disorders. "All mental disorders often involve a 'negative expectancy bias', i.e. the tendency to have a negative expectation pattern. We would like to show how crucial this bias is in the networks of disorders. And to what extent you can then change that with therapy."

What she hopes NSMD will deliver

By the end of NSMD, Evers hopes to have an initial handle on how expectations can be measured in networks, what role they play in combination with other symptoms, and whether it is a generic factor in multiple mental health conditions. Because she also works as a clinical psychologist, she would very much like to see the results put the DSM (Diagnostic and Statistical Manual of Mental Disorders) in a different perspective. "The DSM is hopeless when it comes to, for example, psychological problems associated with somatic conditions. There is only one category for that, which is very limiting and, moreover, not very respectful towards patients. But the insurer will only reimburse the treatment if someone has been given such a simple label. It would be great if there were a change to that system, but we should be modest about that, because it is an international system. It is regularly under attack, but whether we are the ones who are going to overturn it, I do not know. In any case, we can give an impetus to the argumentation why it should be different."