What is the placebo effect?

The placebo effect is very complex and tricky to define. Dictionaries describe the placebo effect as “a beneficial effect produced by a treatment, which cannot be attributed to the properties of the placebo itself”. This is not incorrect, but it doesn’t convey the complexity of the placebo effect and what we know about it so far. Instead, it may be more accurate to define the placebo effect by what it is not.

What the placebo effect is not

A sugar pill

Whilst placebos often are sugar pills or saline injections, they can include a range of other interventions, including surgical procedures.

An inert substance

The placebo effect is often described as ‘an inert substance’. This is not an accurate statement for several reasons:

  1. A placebo does not need to be a substance. Often placebos are sugar pills or saline injections, but other interventions, including surgery, can be placebos too. 
  2. The term “inert” suggests that the placebo has no effect or is lacking active properties. On the face of it, this appears to be true. But it is called the placebo effect for a reason, because placebos do have an effect. Remarkably, we know very little about how the placebo effect works. It is often regarded to be psychological in origin, but placebos can even produce measurable effect in animals, which makes this a much more complex mechanism to uncover. Many placebo researchers refer to “placebo effects” rather than the singular (“placebo effect”), to stress that placebos may work via a number of different mechanisms. In some situations it may be relevant to describe a placebo as an inert substance, but you should be aware of the complexity of this.

A lie

People often describe something as being “just the placebo effect”. This is often meant in a derogatory way, to imply that an intervention doesn’t work or that you have to be gullible to believe it will work. This mistaken preconception is largely shaped by the early work on the placebo effect, which focussed on disproving charlatans and sham-treatments. However, this is not how placebos are used in clinical trials (in clinical trials, placebos provide a baseline measurement, to allow them to measure the true effects of the active ingredient in a drug for example). In addition, Ted Kaptchuk and his team at Harvard have had great success with open-label placebos. When open-label placebos are used, the patient is told that they are being given a placebo. This is often combined with an explanation of why the placebo could have a benefit for the condition at hand. Therefore, placebos do not always require deception to work. 

A negligible effect

The placebo effect is a significant enough effect to require it being incorporated into most clinical trials, to demonstrate the true effect of the intervention they are testing. Therefore, the placebo effect cannot be scientifically negligible and should not be regarded as a negligible effect. In addition, the degree of placebo response can vary from person to person and it appears that personality traits may play a role. Research has not yet demonstrated whether it is possible to encourage people to respond more strongly to the placebo effect or not, but often the more expensive, or the more invasive a placebo intervention is, the stronger the effect. 

It’s all in the mind

Many people believe that the placebo effect is purely psychological or that it doesn’t have any lasting physical effects. This is not correct for several reasons:
1. The mechanisms of the placebo effect are not yet completely understood, but the effects of placebos have been measured at a cellular (neuronal) level. 

2. Both animals and humans are able to respond to the conditioned placebo effect (see below for more information) and this is also measurable at the neuronal level

3. Open-label placebos have been verified (for more details see below). Open-label placebos mean that the patient knows that they are receiving a placebo. Patients have demonstrated positive results to open-label placebos even when they have approached them with some scepticism. Ted Kaptchuk argues that it is not entirely about the patient believing that the treatment will make them better, but it is also about the rituals involved in medicine, illness and recovery. 

4. Some people have reported life changing effects of placebos, with their symptoms vastly improved or even completely resolved. Often the symptoms are also imperially measurable. If placebos acted exclusively psychologically, you would not expect to see this type of improvement.

Why should we care?

Part of the effectiveness of almost every clinical intervention (drugs, surgery etc.) is attributable to the placebo effect. If we can work out how to harness our body’s innate ability to heal, we should be able to make our treatments more effective, or even to develop new approaches that could help create new treatments.

Yekize & the placebo effect

At Yekize, we are committed to promoting the placebo effect and how it can be used to improve global health outcomes. With this in mind, we focus most of our efforts towards the most clinically applicable types of placebo effect: open-label placebos and placebo conditioning. On top of this, we also have a holistic approach to the placebo effect. We subscribe to placebos  being ‘the whole ritual of the therapeutic act”, not just sugar pills and saline injections. Here, we give you a bit more details about these different aspect of the placebo effect. 

Open-label placebos

Open-label placebos are placebos that are given to a patient who knows that they are receiving a placebo treatment. For decades, people assumed that deception was necessary for the placebo effect to occur, but no one had ever tested this theory, until Ted Kaptchuk came along. Ted Kaptchuk and his lab at Harvard, put the theory to the test and discovered that patients can respond well to open-label placebos, with life-changing effects for some patients. When providing open-label placebos, Ted Kaptchuk also gave the patients information about why the placebos may help them and he also ensured that the doctor-patient interaction was really positive and individualised. Informed consent is of utmost importance in medical care, therefore we feel that open-label placebos are the type of placebo most likely to be of use in healthcare. 

The conditioned placebo effect

Surprisingly, the conditioned placebo effect is proven to work for both humans and animals. Several years ago, a study was undertaken on rats that mimicked the human lupus disease. They gave them their medication in water sweetened with saccharine. After a while, the medication was removed from the solution, so the rats were only receiving saccharine-sweetened water. Unexpectedly, the rats continued to respond to the sweetened water as if it contained the medicine for a limited period of time. Similar results have also been obtained in humans. But the conditioned placebo effect is not dependent upon taste. A study by Fabrizio Benedetti demonstrated that patients with Parkinson’s disease could be given apomorphine (a Parkinson’s disease medication) for 4 days, then this drug could be replaced by a placebo and they continued to respond to the placebo as if it was the apomorphine for an additional 48 hours. It is worth mentioning that these results are not thought to be attributable to the residual effects of apomorphine (the half-life of apomorphine is 30-60 minutes). So far, no study has combined both open-label placebos and conditioning, however if the outcome of such a study were to be positive, this could be highly beneficial. What Benedetti had demonstrated in his study was that the amount of active medication required during this treatment period could be reduced by 1/3. If this applies to other diseases, and especially if this treatment format could be used cyclically, there is huge potential to make use of this to improve access to medicine. Not only could treatment be 1/3 less expensive, but it could also mean that 1/3 more people could be treated with the same existing supplies of medication. It was this study by Benedetti that originally inspired Yekize. 

The holistic placebo approach

We believe that there are social and environmental factors that can encourage the healing process. It is likely that the mechanisms of these factors may be related to mechanisms of placebo effects. For example, factors such as hospital design and the doctor-patient relationship can have a known and measurable impact upon patient outcome and we believe that in these cases there may be a potential connection with the mechanisms of the placebo effect. Therefore, we do consider these other elements in our work. 

If you’d like to find out more, please check out our Your Questions page. If you still have questions after that, let us know and we’ll do our best answer.