Heroes Not Zombies

There are many interesting studies of the placebo effect which show the potential of a “chemically inert” substance to produce biochemical and physiological changes in a human being, ranging from the release of endorphins to the loss of hair in chemotherapy trials in volunteers given a placebo which they believe might be a chemotherapy drug. One of the most startling I remember reading was where medical students were given either a barbiturate or amphetamine. The former of these drugs is a sedative, and the latter a stimulant. The researchers switched the labels basically – they told the students who were given a barbiturate that it was an amphetamine and those who received the amphetamine were told it was a barbiturate. Amazingly the students experienced the effects of the drug they thought they were receiving even though they were swallowing the drug which should have done the opposite.

Here’s a more recent study which is just as startling. This shows that people taking part in a trial of painkillers experienced pain severity dependent on their expectation.

The volunteers were placed in an MRI scanner and heat applied to the leg at a level where it begins to hurt — set so that each individual rated the pain at 70 on a scale of 1 to 100. An intravenous line for administration of a potent opioid drug for pain relief was also introduced. After an initial control run, unknown to the participants, the team started giving the drug to see what effects there would be in the absence of any knowledge or expectation of treatment. The average initial pain rating of 66 went down to 55. The volunteers were then told that the drug would start being administered, although no change was actually made and they continued receiving the opioid at the same dose. The average pain ratings dropped further to 39. Finally, the volunteers were led to believe the drug had been stopped and cautioned that there may be a possible increase in pain. Again, the drug was still being administered in the same way with no change. Their pain intensity increased to 64. That is, the pain was as great as in the absence of any pain relief at the beginning of the experiment.

The MRI showed brain changes consistent with their reported experience of pain. In other words, despite receiving a powerful painkilling drug, when they were told the active drug wasn’t there, their pain increased – counteracting the “effects” of the drug.

This is yet one more study which shows that the placebo effect is a real effect – it’s not pretend, it’s not about just believing you feel better, it’s not the same as taking nothing. However, what really stimulated my interest in this study was this final quote in the report –

‘We should control for the effect of people’s expectations on the results of any clinical trial. At the very least we should make sure we minimize any negative expectations to make sure we’re not masking true efficacy in a trial drug.’

The “true efficacy”? What’s that then? The effect of the drug with the human taken out? The effect of the drug disregarding the subjective reality of the patient? What world is that? Is that the world you live in? Are there any humans who have no subjective reality? No values or beliefs? No inner experience? And isn’t pain, and pain relief, in fact, a subjective, inner experience? The “true efficacy” of a drug includes the placebo effect. The “true efficacy” of a drug is, in part, dependent on what the prescriber says and does. The “true efficacy” of a drug is the real experience of real human beings.