In clinical trials, there are usually two sets of patients: those who receive the placebo and those who receive the actual treatment. This is because some 30% of patients will respond to sugar pills with improvement of symptoms, based on the belief that they will get better. For this reason, new drugs are only considered efficacious if patients’ improvement while taking them exceeds 30%, or that of the placebo control group in that particular study.
What the Placebo Effect Is
Placebo responsiveness is associated with the “pleasure” neurotransmitter, dopamine. The more the “reward center” (the nucleus accumbens) lights up in the brain with dopamine in response to a reward, the greater the chances that person will be a high placebo responder.
Case Studies of the Placebo Effect
Some of the most striking cases of the placebo effect in action are case studies of patients with split personalities. According to “Placebo: Theory, Research and Mechanisms,” by Leonard White, one patient had one personality that was diabetic, and one personality that was not. Another patient had a split personality in which one had an anaphylactic reaction to citrus, and the other could drink orange juice with no problems.
In another striking case, a doctor cured the genetic and potentially fatal disease of congenital ichthyosis using hypnosis, thinking it was merely a very severe case of common warts. When it was discovered after the fact what had actually happened, other hopeful congenital ichthyosis patients sought out the same doctor. But, knowing as he now did that he was no longer dealing with warts, but with something far more serious, he ceased to believe he was capable of eliciting such a healing response. He never cured another case.
Implications: The Power of the Mind
There’s a great deal of power in our minds. According to “Mind Over Medicine” by Dr Lissa Rankin, less than 2 percent of diseases can be attributed to a single gene (for these, of course, placebo responses would be ineffective), and only some 5 percent of cancer and cardiovascular disease cases are attributable to heredity alone. For everything else, that leaves quite a lot of gray area.
Our minds most definitely play a role in helping us to heal ourselves. They are not all-powerful, but neither can our beliefs be dismissed when it comes to our health. For instance, optimists (those with a positive outlook on life, who believe negative events are temporary setbacks while positive events are lasting) are 45 percent less likely to die within a specific period of time from all causes than pessimists (those who believe negative events are pervasive and positive events are temporary). In general, pessimists are also more susceptible to depression and more likely to get sick, with twice as many infectious illnesses and doctor visits as optimists.
Might there be an explanation for this as simple as hope?