USA, February 22, 2009: In recent decades reports have confirmed the efficacy of biochemically inert treatments in nearly all areas of medicine. Placebos can help not only to alleviate illnesses with an obvious psychological component, such as pain, depression and anxiety, but also to lessen the symptoms of Parkinson’s disease and inflammatory disorders. Occasionally, placebos have shrunk tumors.
Today, cadre of psychologists, biologists, and other behavioral and social scientists view placebos as a key to understanding how the brain can control bodily processes to promote healing.
The latest research has shown that the placebo effect does not always arise from a conscious belief in a drug. Alternatively, it may grow out of subconscious associations between recovery and the experience of being treated, from the pinch of a shot to a doctor’s white coat. Such subliminal conditioning can control bodily processes, including immune responses and the release of hormones.
A team at the University of Duisburg-Essen in Germany and the Swiss Federal Institute of Technology Zurich have demonstrated that such conditioning can have pharmacological effects that mimic those of the drug being given–in this case, altering immune system status. We conditioned rats by first injecting them with the immunosuppressive drug cyclosporine A, which is used to prevent the rejection of transplanted organs. At the same time, we fed the rats water sweetened with saccharin.
The rats apparently associated the cyclosporine with the sweet drink so that, later, feeding them the drink alone weakened their immune systems, presumably because their brain sent messages to the immune system that partially shut it down. Because the rats cannot consciously believe the drink is therapeutic the way a human might, unconscious, associative learning must have depressed their immunity. These findings suggest that a placebo effect does not require that a person hope for or believe in a positive outcome — its roots are deeper and subconscious.
(For more on this fascinating study of the mind’s influence on healing, click on the link above.)