When an IBS episode would strike, her co-workers would cover for her as she huddled in a corner, keeled over in pain. She signed up and was thrilled when she was among about 80 people selected to take part in a first-of-its-kind clinical trial. The doctors told her there were no active ingredients in the pills, and the word placebo was labeled clearly on the bottle. Three weeks later, after taking the pill twice daily, Buonanno was symptom-free. She had never gone so long without an attack.
But Ted Kaptchuk, a professor of medicine at Harvard Medical School and one of the leading researchers on the placebo effect, wanted to take his research further. He was tired of letting the people in his studies think they were taking a real therapy and then watching what happened.
Instead, he wondered, what if he was honest? His Harvard colleagues told Kaptchuk he was crazy, that letting people in a clinical trial know they were taking a placebo would defeat the purpose. The findings were surprising. Nearly twice as many people in the trial who knowingly received placebo pills reported experiencing adequate symptom relief, compared with the people who received no treatment.
Not only that but the men and women taking the placebo also doubled their rates of improvement to a point that was about equal to the effects of two IBS medications that were commonly used at the time. So far the researchers have treated patients; they are hoping to treat a total of people with IBS via their ongoing clinical trial. Not everyone agrees that honest placebos work. The placebo effect has a long medical history. Beecher observed that many wounded soldiers declined morphine to treat their pain, despite the fact that civilians with similar injuries would demand it.
Today placebo is well recognized in modern medicine. Some experts believe the nocebo effect accounts for at least part of the growth in people reporting food sensitivities to gluten and dairy.
Researchers are learning that placebo has nuance too. In philosophy-speak the possibly mistaken inference that the placebo caused the cure is called the post hoc ergo propter hoc after, therefore because of fallacy. To test whether placebos really make people better, we have to compare people who take placebos with people who take no treatment at all. They looked at three-armed trials that included active treatment, placebo control, and untreated groups.
Then they checked to see whether the placebo was better than doing nothing. They found a tiny placebo effect that they said could have been an artefact of bias. They included anything labelled as a placebo in a trial for any condition.
Such a comparison of apples and oranges is not legitimate. If we looked at the effect of any treatment for any condition and found a tiny average effect, we could not conclude that treatments were not effective.
I exposed this error in a systematic review , and now it is widely accepted that just as some treatments are effective for some things but not everything, some placebos are effective for some things — especially pain. Recently, placebo-controlled surgery trials have been used. In perhaps the most famous of these, American surgeon Bruce Moseley found patients who had such severe knee pain that even the best drugs had failed to work.
He gave half of them real arthroscopy and the other half placebo arthroscopy. Patients in the placebo arthroscopy group were given anaesthetics and a small incision was made in their knees, but there was no arthroscope, no repairing of damaged cartilage, and no cleaning out of loose fragments of bone.
To keep the patients ignorant about which group they were in, the doctors and nurses talked through a real procedure even if they were performing the placebo procedure. A review of over 50 placebo-controlled surgery trials found that placebo surgery was as good as the real surgery in more than half the trials. In the first of the studies of open-label placebos placebos that patients know are placebos I know of, two Baltimore doctors by the names of Lee Park and Uno Covi gave open-label placebos to 15 neurotic patients.
The patients took the placebos, and many of them got better after having the placebo — even though they knew it was a placebo. After the placebo made them better, they thought the doctors had lied and actually given them the real drug. More recently, several higher-quality studies confirm that open-label placebos can work.
All 51 patients had received a painkiller called mepivacaine for the surgical procedure. Then, at three and four hours after the surgery, the patients were given either morphine, a placebo or naloxone.
Naloxone is an opioid antagonist, which means that it stops drugs such as morphine and endorphins from producing their effects. It literally blocks the cell receptors, so it stops morphine or endorphins from docking onto those receptors. The researchers found that naloxone blocked the painkilling effect of placebos.
The company was started by a mother with three young children, who has appeared on the morning television shows in the US to publicise her inspiration. The pill is called Obecalp—placebo spelt backwards. How clever is that? I first became aware of the power of placebos 30 years ago when I was an intern in a large US urban hospital. Someone in a trial might have a stomachache for any number of reasons that are not related to the trial.
Because they are in a trial, they think the trial intervention caused the ache, misattributing the cause. This gets reported as an adverse event, when in fact it would have happened anyways. Sometimes the way patients are warned about adverse events makes patients believe they will get an adverse event like a stomachache , and that can cause them to actually experience it.
There was no data about what the trial participants in our study were provided in our study. However, we know from other studies that the way patients are warned about adverse events can affect whether they report them. For example a study published last year in The Lancet found that patients were more likely to report adverse events when they knew they were taking statins. When they had no idea, there was no increase in muscle-related effects.
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