Psychoneuroimmunology Health Article

Definition

Psychoneuroimmunology (PNI), is a relatively recent branch of science that enforces beliefs that physicians have held for many centuries, perhaps well before the times of the ancient Greeks. The premise is that a patient's mental state influences diseases and healing. Specifically, PNI studies the connection between the brain and the immune system.

Origins

The term psychoneuroimmunology was coined by Robert Ader, a researcher in the Department of Psychiatry at the University of Rochester Medical Center in Rochester, New York. In the 1970s, studies by Ader and other researchers opened up new understandings of how experiences such as stress and anxiety can affect a person's immune system.

In the 1970s, Ader performed experiments on lab rats, which showed that environmental factors could impact the immune system. Ader's work went against accepted scientific knowledge, which held that the immune system was not related to other bodily systems, and had no way to physically interact with the nervous system. However, other studies confirmed Ader's findings. The field of PNI blossomed, and hundreds of studies explored various interactions between the immune system and other mental and physical processes.

Many PNI studies have focused on how stress, hostility, and depression impact the immune system. Many conditions such as heart disease, osteoporosis, arthritis, delayed wound healing, and premature aging, are related to stress and negative emotions. Fewer studies have been aimed at showing the benefits of happiness, or positive emotions, on health (perhaps because this is more difficult to test).

Many doctors have noted that a patient's desire to get well is related to the outcome of a disease. Clinical anecdotes recount cases of miraculous healing for no demonstrable reason, or cases where a terminally ill patient held on for months longer than expected to make it to a daughter's wedding or other important occasion. Faith in the physician (or shaman or other healer) has also long been thought to influence healing. The ancient Greek physician Galen wrote, "He cures most successfully in whom the people have the most confidence."

The placebo effect is also a curious aspect of healing. A placebo is a sugar pill or other non-active prescription, which might be given so that the patient thinks he or she is being treated medically. The actual incidence of the placebo effect is difficult to measure, but some researchers believe that as many as one-third of all patients will improve on a placebo.