Five ways ‘honest’ placebos can help

Placebos can be powerful tools for treating anxiety, depression, and chronic pain. But the assumption that the patient must be deceived into believing that they are getting an active treatment, rather than an inert drug, means that some medical practitioners feel it is unethical to use them.

These practitioners may be pleased to hear that there's growing evidence that 'honest', 'open-label', and 'non-deceptive' placebos can work, too. In these studies, patients are usually told that they are not being given an active drug, but that there's evidence it might help anyway. According to some recent findings, this honest approach can (in certain cases) be as effective as deception.

Easing stress

'Just think: what if someone took a side-effect-free sugar pill twice a day after going through a short, convincing video on the power of placebos, and experienced reduced stress as a result?'

This was the question posed by Darwin Gueverra at Michigan State University in the wake of his team's 2020 research on almost 300 people, which investigated the effects of an honest placebo on distress. In this study, those who were first given a saline nasal spray – which they were told contained no active ingredients but which would help to reduce negative feelings if they believed it would – not only reported feeling less emotional distress when shown disturbing images but also showed weaker brain signals of distress.

As a next step, Gueverra wanted to try this approach in a real-world situation. And in 2024, he and his colleagues reported findings from a trial of 61 people who said they were suffering prolonged stress from the COVID-19 pandemic. The non-deceptive placebo group watched short videos on placebos, placebo effects, and how placebos can still work even without deception. 

During a Zoom session with an experimenter, they were then told that they'd be sent a batch of non-deceptive placebo capsules, which they should take twice a day for two weeks. At the end of this period, the team found that compared to a control group, these participants reported significant reductions in Covid-related stress, overall stress, anxiety, and depression. This led them to conclude that 'non-deceptive placebos, even when administered remotely online, offer an alternative and effective way to help people manage prolonged stress.'

Assuaging guilt

Guilt can have an important role in our lives, in telling us that we've transgressed, and encouraging us to apologise or own up. However, some people suffer disproportionate and debilitating feelings of guilt, even when they've done nothing wrong. In 2022, Dilan Sezer at the University of Basel and colleagues reported work that suggests non-deceptive placebos may also be able to help with this.

In this study, 109 healthy participants were asked to write about a time when they had ignored important rules of conduct, treated someone close to them unfairly, or hurt or even harmed them. They then rated their feelings of guilt, shame, and pride. About a third were then given a deceptive placebo – a pill that they were told had a calming and comforting ingredient that could reduce feelings of guilt.

They were also told that placebos have effects because people expect them to work and because they have learned to associate taking pills with noticeable effects. A second group was given the same pill, but they were told that it was a guilt-reducing drug with no further elaboration. A third, control group received no treatment.

The team found that both the deceptive and the non-deceptive placebo were, compared with the control, effective at reducing guilty feelings. 'These results indicate not only that guilt is amenable to placebos, but also that placebos can be administered in an ethical and potentially emotion-specific manner,' the team wrote.

Combatting physical pain

'It is often suggested that open-label placebos are less effective than deceptive placebos,' note the authors of a 2023 study in the European Journal of Pain. To investigate this, the team (led by Leo Druart) told 60 healthy participants that they were studying the effect of a topical cream on pain. Each participant immersed their hand in painfully cold water twice: on one occasion, this was done without the cream, and on the other, cream was massaged onto their hand prior to dunking.

One group, who had watched a video about placebo effects, were told that it was an inert cream that would however make it easier to bear the pain through placebo mechanisms. The other was told that it was an 'effective cream to combat cold-related pain', and that it would make the immersion easier to bear. When the team analysed the participants' ratings of the intensity of their pain, they found that the non-deceptive placebo was no less effective at reducing pain than the deceptive placebo.

Brightening up

While many studies of placebos have focused on how they might reduce unwanted feelings, others are starting to look at whether they can boost positive feelings and practices. In a 2021 paper in Scientific Reports, Anne Schienle and Isabella Unger at the University of Graz studied 160 students who were asked to complete a 14-day course of progressive muscle relaxation exercises at home. Half were told about placebo effects and given a bottle of sunflower oil marked 'placebo'. They were asked to take three drops before each session.

The results showed that, in fact, this group didn't report feeling any more relaxed than the control group at the end of the study. However, they did complete more exercises. The work suggests, therefore, that non-deceptive placebos might help people stick to physical programmes that should, perhaps in the longer run, be beneficial for them. In relation to this, there's emerging evidence that non-deceptive placebos can help boost motivation and performance in sport and exercise.

Encouraging kindness

In 2023, Anne Shienle and Isabella Unger followed up their earlier work on relaxation exercises with a study that explored whether non-deceptive placebos can encourage people to perform more acts of kindness. A total of 160 participants were asked to make a plan to perform one act of kindness – such as helping someone out or showing concern for them – every day for a week. 

About half of the sample was told that placebos, even non-deceptive ones, have been shown in scientific research to produce significant improvements in various conditions, and some of these studies were described. They were also told about how the placebo effect works, and given a bottle of sunflower oil, marked 'placebo', from which they were to have three drops each morning in order to 'help them to complete the acts of kindness'. A control group was not given this placebo.

During the following week, the placebo group performed more acts of kindness. While the difference between the two groups wasn't big (on average, placebo-takers performed 5.8 acts of kindness, compared with 5.2), the non-deceptive placebo did, it seems, enhance the participants' motivation to stick to their planned kindness.

It's widely accepted by researchers in the field that, for non-deceptive placebos to work, participants have to be given a rationale for why they should help. Some researchers also suggest that this information should be supplied by a friendly, approachable, authoritative person. 

However, the Covid-19 study by Gueverra and colleagues did find that in-person meetings weren't required and also suggested that the person 'prescribing' the placebo does not have to be a medical or mental health professional. Perhaps ethical, side-effect-free, very cheap placebos, which are easy to take and don't have to be issued by medical professionals, could in time be a useful tool for the arsenal. Further work will tell.