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Clues from Hypnosis and Placebo Effects

Early researchers in psychosomatic medicine received a powerful clue that a disorder might be influenced by psychological factors when hypnosis was found to alter a medical condition. Hypnosis involves no drugs or other medical treatments, so changes occurring due to hypnosis must be psychological in origin.

An example of the power of hypnosis is its ability to make warts disappear. In an essay from his book Lives of a Cell (1979), Lewis Thomas—noted biologist, past president of Sloan-Kettering Cancer Center, and professor of pathology and medicine at Cornell—wrote as follows:

Why did warts fascinate Lewis Thomas?

Warts are wonderful structures. They can appear overnight on any part of the skin, like mushrooms on a damp lawn, full grown and splendid in the complexity of their architecture. Viewed in stained sections under a microscope, they are the most specialized of cellular arrangements, constructed as though for a purpose...

And they can be made to go away by something that can only be called thinking... This is a special property of warts that is absolutely astonishing... It is one of the great mystifications of science: Warts can be ordered off the skin by hypnotic suggestion. [p.47] fictitious

What evidence did Thomas cite?

Thomas cited two sources of evidence, one anecdotal, the other experimental. The anecdotal evidence came from a "distinguished old professor of medicine" who said he merely painted a colored substance on a wart and assured the patient it would be gone in a week "and he never saw it fail." The research evidence came from a "meticulous" study by "good clinical investigators" in which 14 patients with "seemingly intractable generalized warts" (in other words, lots of warts that would not go away) were hypnotized.

The suggestion was made that all the warts on one side of the body would begin to go away. Within several weeks the results were indisputably positive; in nine patients, all or nearly all of the warts on the suggested side had vanished, while the control side had as many as ever. (Thomas, 1979)

What happened when a subject in the hypnosis/warts study got left and right confused?

One of the subjects got right and left confused, which is common even without hypnosis. That person "destroyed the warts on the wrong side."

This example raises profound questions. How can a mental event like suggestion produce a specific biological response that targets an isolated structure on the skin? When scientists can answer that question, they will be able to answer many other questions about mind/body interactions.

What are some examples of powerful placebo effects?

Placebo effects also suggest a psychological role in many disorders. Patients believe they are getting a genuine medicine when they receive a placebo treatment. (That is what defines it as a placebo treatment.) Brown (1998) summarizes the many powerful effects of placebos or "inert substances" presented as medicines. For example, "Typically, 30 to 40 percent of depressed patients benefit from taking a placebo." (Brown, 1998, p.91). In one study of the beta-blocker propranolol, often prescribed after heart attack, people who took the drug experienced a 50% reduction in death rate, compared to a control group. However, people who took a placebo pill also experienced a 50% reduction in death rate! No wonder Brown's article was subtitled, "Should doctors be prescribing sugar pills?"

What is Brown's explanation of placebo effects?

Brown suggests that placebos may achieve their effect by reducing stress and anxiety, "lessening the apprehension associated with disease." He notes that placebo effects are most powerful with disorders known to become worse when a patient is upset, such as high blood pressure, asthma, and chronic pain. He concludes, "It is not inconceivable that by reducing anxiety, placebos could influence countless diseases, including some that we do not usually think of as subject to psychological influence" (p.93).

One student discovered that this worked for a gastrointestinal disorder:

When I was a junior in high school, I developed a "nervous stomach." Every time I was in a stressful situation I would have terrible stomach cramps and throw up. I went to the doctor, and he prescribed some "stomach relaxers." Every time I got nervous, I took one of those pills and they relaxed me. Years later, after I had gotten over my nervousness, I found out that the pills were placebos-sugar pills. Apparently because I thought that the pills were helping me, I learned to relax myself. [Author's files]

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