Fake Medicine: Doctors' not-so-new cure

The power of placebo and association in treatment

A placebo is anything that appears to be a ‘real’ medical treatment but isn’t. The placebo effect is when a placebo treatment has a beneficial effect that can’t be attributed to the placebo itself and must, therefore, be due to the patient’s belief in the placebo. Historically in clinical trials, the placebo effect was considered a sign of failure. In the trial, one group would be given the actual drug and the other a placebo with no effects. If both groups had the same reaction the drug would be deemed not to work.

However, more recently, experts have discovered that the placebo effect has nothing to do with the drug that is being taken and is actually a result of a different mechanism. It is not fully understood why placebos work but it could be to do with the fact that someone’s belief in medicine could cause the release of neurotransmitters like dopamine and endorphins which make them feel better. It could also be a result of the extra care and attention they feel they are getting as a result of the trips to hospital and procedures that a clinical trial involves, or the ritual of medicine taking which the body associates with feeling better.

The associative power of the brain has other uses in medicine as well. Have you ever eaten a food that made you sick, and then been unable to face it for weeks or months after? This is called conditioned taste aversion and is now being used to help patients who have to take drugs with bad side effects. As the body learns to associate the taste of a food with the response it causes in the body, so it can learn to associate the taste or smell of medicine with the effects it has. For example, in one study, when rats were given sugar water and Cytoxan, an immunosuppressant drug which made them feel sick, they learned to associate the sweet taste with the medicine and avoided sugar water when offered it later.

What is really amazing is that when the rats were later force-fed sugar water, they all died of infections as a result of their immune systems not responding to the disease. They had not only learned to associate the sick feeling the Cytoxan gave them with the sugar water, but also the immunosuppressant effect it had.

This can be used to the benefit of humans who need to take medication with harmful side effects regularly. The patient is given a dose of the drug while smelling a specific smell or drinking something with a distinctive flavour until they learn to associate that with the effects of the drug. Then their dosage can be reduced because as long as they still smell or taste the same thing regularly, they will still experience the same physiological effects their body has learned to associate with that sensory experience. This means the person can still receive the benefits of the drug without the harmful side effects.

Ruby V