The science of the placebo versus placebo science

Recent years have been politically tumultuous; elections and referenda are seldom out of the news, and politicians seek ever more extreme positions to gain media attention and votes. It appears widely accepted that we are living in the ‘post-truth’ era.

Saturday’s March for Science was an international response to what many scientists see as unjustified post-truth challenges to the credibility of science. Whilst most scientists accept that there is room for the objective criticism of even the most robust scientific findings, many see current criticism as emanating from political and commercial agendas. Some describe the current situation as ‘a global and political assault on facts’.

US science journalist Bill Nye, known to generations of US schoolchildren as ‘Bill Nye the Science Guy’, was a key figure in the March for Science. He has been a vocal opponent of poor science, pseudoscience, and non-science for many years.

On Friday, 21 April, Bill Nye launched a new science TV programme, ‘Bill Nye Saves the World’, aimed at presenting important science to a popular TV audience. I was invited to be a guest on this show, due to my work on placebo effects, and to take part in a debate on the effectiveness of complementary and alternative medicines (known as CAM).

With many people choosing CAM, this as the result of the proliferation of CAM treatments and decreasing confidence in (and availability of) publicly-funded healthcare, it is increasingly an emotive issue. One of the reasons that it so emotive is that many patients choosing CAM may be forgoing more effective evidence-based treatments. In doing so they may either require late conventional treatment at a point in time at which symptoms have become more severe, or run the risk of their health deteriorating significantly.

I was asked to speak on Bill’s show because it is widely recognised that many CAM treatments work via the placebo effect. Placebo effects are complex but amount to this: a patient’s belief that they have received a treatment for an illness can offset some or all of the symptoms of that illness. Over the last 20 years it has become apparent that physiological processes in the brain, particularly the action of the neurotransmitters dopamine and serotonin, are the mechanism of many placebo effects. There is now good science behind the placebo!

This growing neurophysiological evidence base for the placebo effect has however been seen by many people as legitimising CAM. That is, if there is a placebo effect when a person receives a CAM, and that placebo effect has clear neurophysiological mechanisms, those mechanisms must also constitute the legitimate mechanism of the CAM.

This is not the case. There is a stark contrast between the lack of research into the broad effects of placebos compared with the robust evidence base for many medicines. There are also potential negative effects of placebos (nocebo effects), and significant variability in individual responses to placebos compared to traditional medicines. In short, treatments based on the placebo might have uncertain and unanticipated effects.

This was the message I tried to present on Bill’s show, but in doing so I reflected on a more subtle link between the placebo effect and the current scientific situation.

The placebo effect is by definition inauthentic; there is no substance to a placebo, and it only works because the patient believes it will. If it does work, it becomes reality to that person, if only for a brief period (there is little research on the effects of placebos over time). In many respects the placebo effect exemplifies the post truth era, one in which the inauthentic idea – placebo science if you will – is gaining wide acceptance, and becoming accepted as legitimate by many.
The sentiment expressed by many of the speakers at the March for Science events on Saturday was clear: in the same way in which treatments based on placebo effects are in inauthentic and may not be effective, perhaps even leaving the patient requiring more treatment at a point in time when it may be too late, we must not let false accounts of science lull us into an equally false sense of security and delay critical progress in relation to food security, climate change and medicine. The proliferation and promotion of poor science, pseudo-science and non-science by politicians and corporations undermines the public’s confidence in science-based medicine – which saves millions of lives every year – and in science generally.

Scientists everywhere should ensure that they seek every opportunity to promote good science to as wide a range of the public as possible. The placebo science seemingly widely propagated at present, like placebo medicine, might have uncertain and unanticipated effects.