The Placebo Effect

In any investigation of the effects of psychotherapy or a new drug, it is important to include control conditions, including at minimum a no-treatment control and at least one placebo condition.

The no-treatment condition measures change over time, while the placebo condition assesses the effect an inert substance or “phony” treatment. Individuals do get better with the passage of time and their belief that they have been given a particular treatment by a physician, who they like and in whom they have confidence.

In his article “The Power of Nothing” in the New Yorker (12/12/11), Michael Specter describes some recent experiments and current thinking on the effects of placebos. The work of Ted Kaptchuk, director of a Harvard institute dedicated to the study of placebos, constitutes a major portion of the article. Kaptchuk had previously practiced acupuncture in China

Soon after returning to this country he treated a woman for chronic bronchitis who was about to have an operation on her ovaries. A few weeks later the woman returned to his office and reported the pain in her ovaries had disappeared. Kaptchuk comments to Specter, “There was no fucking way needles or herbs did anything for that woman’s ovaries. It had to be some kind of placebo…”

Yet it is well known that a patient’s expectations can have a profound effect on the healing process and probably plays a role in any medical intervention, sometimes more so than others. And a good deal of the variability can probably be attributed to the patient, as some respond more to placebos than others, as well as the physician or therapist as some are better than others. They engender more confidence and probably have a good deal more “charisma.”

Kaptchuk considers himself one of the better ones. “I am a damn good healer. That is the difficult truth. If you needed help and you came to me, you would get better. Thousands of people have. Because, in the end, it isn’t really about the needles. It’s about the man.” Perhaps that sort of confidence is all it takes.

Specter describes several recent studies of the placebo effect. In one, “Patients [post-operative] who were told that they would receive a painkiller, whether they actually received it or not had the same experience in the trial as those who secretly received between six and eight milligrams of morphine—a significant amount.”

In a study of irritable bowel syndrome, one group received a placebo pill twice a day while those in the second received nothing. Before the study both groups were informed that placebos are inert sugar pills that are not effective. They were also informed that previous studies had demonstrated that placebos have significant healing effects. The results showed that the patients who were fully informed about placebos scored much better on standard measures of their condition than those who received nothing.

Other studies have shown that the larger the pill, the stronger the placebo effect. “Two pills are better than one, and brand name pills trump generics. Capsules are generally more effective than pills, and injections produce a more pronounced effect than either. There is even evidence to suggest that the color of medicine influences the way one responds to it…”

Taken together these studies provide fairly compelling evidence of the power of placebos.

Kaptchuk believes that even it’s all in your head, there must be some biological mechanism driving these reactions. Trying to unravel what that mechanism might be is the direction of his current research.

Kaptchuk admits, however, “I am sure I do not understand the placebo effect. I ask questions, hopefully valuable questions and we will see where the research lands.”