DICK POUNTAIN
The placebo effect offers us insights that researchers shouldn’t ignore, whether they work in AI or vaccine research
The much-discussed placebo effect offers us insights that researchers shouldn’t ignore –whether they work in AI or vaccination research.
It feels as though the Covid-19 pandemic has made virologists and epidemiologists of all of us. People are suddenly following vaccine development with sport-like devotion and discussing the difference between cytokine and bradykinin storms at the bus stop. Or perhaps that’s just my circle of hypervigilant friends.
This interest has a practical focus, since returning to any semblance of normal life depends to a great extent on success in a vaccination program. But I sense there’s another dimension to it: it makes us feel better when we understand what’s happening to us and gives us a sense (perhaps illusory) of control. This increased confidence can in some cases affect our real bodily functions via the “placebo effect”.
Medical science has only recently started to take the placebo effect seriously, but its power appears remarkable. The effect was dismissed for a long time for the very good reason that it conflicts with the central dogma that separates science from magic, namely that the mind cannot directly affect matter (without which we’d still be using “eye of newt” instead of dexamethasone). That’s changing as we learn about the material pathways that exist between software processes in the brain (that is, thoughts) and bodily processes. These pathways are mostly chemical rather than electrical, depending upon hormones and neurotransmitters distributed via the bloodstream. Incidentally, this is one more reason why the pursuit of AI will remain stunted so long as it treats intelligence solely as a computational function of the brain, ignoring the intimate two-way communication between brain and the rest of the body’s organs.
Acceptance of the placebo effect began in the pharmaceutical industry as it introduced drug trials and discovered that a placebo – that is a fake pill, often just sugar – could sometimes produce an effect similar to the real drug. At first, explanations were purely psychological, concerned with expectation: if you expect a pill to cure your headache, it might. The placebo effect remains a problem for drug trials, as untangling it from the real drug effect is difficult. There’s also an opposite “nocebo effect” where patients who are informed of possible side effects of a drug can experience or intensify them.
Psychological explanations raise a tricky question over whether such effects are imaginary or physical – a question that also arises about illnesses that medicine suspects may be psychosomatic. The emphasis nowadays is shifting: not to discount psychological approaches entirely but to explore how the mind affects bodily systems. “Placebo analgesia” occurs when the mental expectation of relief stimulates the limbic system to release hormones called endorphins that behave like opiates. The mere anticipation of an antidepressant can release dopamine and thus improve mood, ditto for insulin and blood sugar or vasopressin and blood pressure. It’s even been demonstrated that patients can be conditioned, Pavlov-style: administer a drug in a drink with a distinctive taste and, when the drug is removed, merely tasting the drink may produce its effect. In short, the placebo effect reveals yet another bodily system that functions as a computational control system separate from, and in parallel with, the brain.
These placebo pathways can be trained and nurtured to an extraordinary extent, so that they become the basis of practices like yoga and acupuncture, or even the source of what would have once been called miracles. Wim Hof, a 61-yearold Dutchman, can immerse himself in iced water for 45 minutes and swim 50 yards under the ice of a frozen lake by conditioning his breath control. Free divers train themselves into feats of breath-holding approaching 20 minutes. Italian placebo scientist Fabrizio Benedetti gave weightlifters what he told them was a performanceenhancing drug, but it was a placebo; he also secretly gave them lighter weights, which convinced them that the drugs were working. When he surreptitiously restored the normal weights, the muscular force they were able to exert increased while their perceived fatigue remained the same.
I suspect there’s a lot more yet to discover about the placebo effect, with enormous consequences for not only medicine, but sport, tech and daily life. There’s already evidence that it can even stimulate the immune system, although the idea of its ever being trained to resist infections such as coronavirus seems unlikely at the moment. Either way, such slim hopes are certainly no excuse either to slacken the effort to develop vaccines, nor to stop persuading anti-vaxxers that they’ll need to accept them.
The placebo effect conflicts with the central dogma that separates science from magic, that the mind cannot directly affect matter
Administer a drug in a drink with a distinctive taste and, when the drug is removed, merely tasting the drink may produce its effect