We hear a lot about the placebo effect, that remarkable ability we have to make ourselves feel better through the belief that something beneficial is happening to us. Occasionally it's sold to us as the power of positive thinking, or just looking on the bright side, being optimistic, expecting good things to happen. But how does it work? How can we kid ourselves so effectively? What is really going on?
The placebo effect is certainly very well supported by evidence. People report that they feel better when told they are being given treatment for an ailment, even when the treatment is fake. As long as they believe they are getting something, they behave as if they were actually getting it. They will report that pains have lessened, that conditions have improved, that they feel different, better.
Two questions arise from this. First, has anything changed to make them feel differently, perhaps in their brain chemistry, or in their perceptions? And secondly, has anything actually changed in the body, in the condition of the ailment itself? The first is about the brain's perception of the state of the body, and the second is about the state of the body itself. They are very different questions and both are important.
Our brains construct representations of reality that allow us to negotiate the world very effectively. Not only do we perceive the world through our senses, but being part of the world, we also perceive sensations from our own bodies. Normally, the brain suppresses many of these sensations which we would otherwise feel, because we would be inundated with signals from all parts of our bodies. That would render us unable to discriminate between the important and the mundane.
Our brain discriminates and lets us ignore the unimportant signals from our body in favour of the significant ones that help us move around in the world. That filtering of our body sensations is one of the reasons you can't tickle yourself. Your brain desensitises your perceptions to help you focus on the important things in the external world.
But the brain also constructs our mental world. We learn to empathise by mimicking the expressions of people we see, and this in turn creates similar emotional changes to those we are observing, and hence similar changes in brain chemistry. Just the slight action of copying some facial expression that we see in others, triggers changes in our brain chemistry which produce similar feelings. This is the key to understanding the placebo effect.
Not only can physical mimicking produce these subtle brain changes, so can expectations, predictions, memories. Thinking of some frightening event can generate a change in the state of the brain, and in turn increase adrenalin. Remembering a deceased loved one can produce changes in the brain areas associated with grief. Expectation and conditioning behave in just the same way. All of these changes can be seen in brain scans such as fMRI scans, and they are very well evidenced. Anticipation and expectation affect brain chemistry.
Now let's think about a patient presenting with a pain in the doctor's surgery. The patient has been culturally conditioned to expect that the doctor will be able to alleviate the pain, and therefore has an expectation that the pain will reduce. There will already be an effect on the opioid level in the brain, even in the absence of any treatment, so there is a likelihood that the patient will report feeling better.
Such changes in brain chemistry are also brought on by expressions of sympathy, paying attention, listening, in short any kind of consultation.
All of this is a well-established explanation for why patients report that they feel better. But are they in fact better? In other words, has there been some consequential change in the state of their bodies which cured the original ailment?
In those cases where stress or anxiety is a major factor, clearly reducing stress and anxiety addresses a primary cause. If the changes in brain chemistry brought about by the consultation, the expression of sympathy and concern, reduce stress and anxiety, then there may be a consequential improvement in the underlying condition. A cause has been addressed. A stress-induced ulcer may well respond to the reduction in stress brought about by a sympathetic consultation.
But if the illness was caused by other factors, for example trauma, the situation is rather different. Although stress and anxiety will affect the state of the body and can impede healing, the question is whether or not the placebo effect in itself is any form of treatment.
Medical practitioners have an ethical problem with telling patients lies, even if believing them might make them less anxious, more positive, more affected by their own opioids. They are well aware that illnesses have real causes not addressed by the placebo effect. Bacterial infections, trauma, organ diseases, hormonal problems, blood disorders – the list is practically endless. In every case the placebo effect is restricted to making the patients feel better without addressing the causes.
The placebo effect is not treatment but it is useful in making patients feel better. However, for the placebo effect to work, there has to be a lie told to the patient, and the patient has to continue believing it. That makes it a very faulty mechanism for effecting any kind of physical change. We cannot even reliably predict who will be susceptible to the placebo effect (some reports say less than 30% of us), nor in what circumstances, nor how long it might last. So it's not a basis for treatment.
Many practitioners of alternative medicine believe strongly that the cure is evidenced by people reporting that they feel better. For ailments that clear up on their own, these practitioners often cite patients' anecdotes as evidence of efficacy. But without a clear diagnosis of the evidence-based actual causes, they are not justified in claiming any kind of cure or treatment. Without being able to discount the placebo effect through controlled trials, and demonstrate the efficacy of their treatment under strict conditions, they cannot justify their claim to be offering any treatment at all.
The placebo effect is a change in brain chemistry brought about by a conditioned reflex, together with the neurochemical consequences of expectations. It affects our mental picture of our state but that may not be an accurate representation of our real state. We can feel better without actually being better. It's nice to feel better when we're sick, but it's infinitely better to be cured.
It is very lucrative to sell the placebo effect, but telling the difference between it and a real cure is essential for genuine health care. When alternative practitioners say that placebo is enough, they are misunderstanding the physical causes of illness. Selling feel-good is not selling cure.