July 18, 2012

ALL IN YOUR HEAD:

Are Warnings About the Side Effects of Drugs Making Us Sick? (Steve Silberman, July 16, 2012, Plos)

[A] provocative new report by Winfried Häuser, Ernil Hansen, and Paul Enck in the journal of the German Medical Association suggests that the side effects of some drugs, and the discomfort of certain medical procedures, may be inadvertently intensified by doctors and nurses trying to keep patients fully informed of the consequences of their medical care. The culprit behind this phenomenon is the nocebo effect.

You can think of the nocebo effect as the evil twin of the placebo effect -- the body's healing response to the act of taking a pill or receiving medical care, even if the pill itself is inert. The most familiar example of the placebo effect is what happens in trials of experimental drugs. One group of volunteers is randomly assigned to take the drug in question; another group is assigned to take placebo -- a fake drug designed to look just like the real one. Neither the volunteers nor the staff know which group is which. If the drug group improves significantly more than the placebo group, the drug is judged to be effective. This kind of test -- the double-blind, placebo-controlled trial -- has been the gold standard of drug development in medicine for half a century.

In real life, gauging the effectiveness of a new medication is not quite that easy. In 2009, I wrote a widely-circulated article in Wired magazine about a mysterious increase in placebo effects in trials in recent years that is making it harder for Big Pharma to bring new drugs to market. I explored some of the reasons that might be happening in the article.

A placebo, you might say, is an ersatz drug that makes you feel better, while a nocebo is a fake drug that makes you feel worse. Of course, in both cases, it's not the pill that's doing the work; it's your own body, responding to the social context in which you take the pill. If a skilled doctor with kindly bedside manner tells you that drug X will reduce the inflammation of a minor injury, it often will -- even if the drug itself is nothing but a capsule full of lactose, milk sugar. One of the astonishing things we've discovered about the placebo effect in recent years is how wide a range of ailments can be ameliorated by it, at least temporarily -- from chronic pain, to high blood pressure, to inflammation, to depression and anxiety, to sexual dysfunction, to the nausea and vomiting caused by chemotherapy. Perhaps unsurprisingly, it turns out that the nocebo effect is equally capable of making you feel more miserable, in a similarly broad range of ways.

One of the most interesting findings in the new report from Germany is about the underappreciated -- and under-studied -- role of nocebo effects in clinical trials.

If you tell a group of trial volunteers that they're testing a new drug that may relieve the pain of migraines, a significant number of volunteers will experience pain relief after taking the drug -- even if they've been randomly assigned to the placebo group and are receiving nothing but sugar pills. The placebo effect in action.

But here's where it gets interesting.  If you tell the volunteers that the side effects of this new medicine may include dry mouth, tingling in the hands and feet, and slight dizziness, some volunteers will experience precisely these side effects -- in both groups. In fact, some volunteers who are taking nothing but sugar pills will be made so uncomfortable by these symptoms that they will choose to drop out of the trial early.

Posted by at July 18, 2012 9:33 PM
  

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