12/04/2015 05:10 pm ET Updated Dec 04, 2016

The Placebo Effect: Harnessing the Healing Power of the Mind

Having performed research for a number of years on the healing effects of both Western medicine and complementary therapies such as Tai Chi and meditation, I'm intrigued by the question of which factors actually contribute to improvements in health.

Do Western and complementary therapeutic modalities share any common healing factors? In our society we generally assume that Western therapies heal and complementary therapies, like meditation or acupuncture, do not. If some improvement comes after a complementary therapy, I've heard people say, "It's just the placebo effect." But what exactly is the placebo effect? And what is its relationship to all forms of healing, not only complementary therapies but Western medicine as well?

The placebo effect, simply defined, is the known tendency for people to improve when given any treatment they think will be efficacious. Western science noticed this tendency years ago and, in fact, uses it to test the effectiveness of new medications. A certain number of test subjects are given placebos -- inactive substances -- and told they're receiving the medication being tested. To pass its trial, the medication must perform significantly better than the placebo. But this brings us to yet another question: How can a mere placebo heal?

Even though we depend on the placebo effect, Western science doesn't understand it. Science does not yet have a way of explaining how thoughts can materially affect our brain and body. This is in part because traditional neuroscience is based on a materialist view of the world, in which neurons are the sole factors producing our mental states, and in which our mind or consciousness cannot affect our physical function.

The term "placebo" originates from the 13th century and reflects the practice of engaging professional mourners for funerals. Such mourners were called placebos (to please) a term used to describe inauthentic grief. Later, medicine began using the term to describe treatments with no curative properties, but which made patients feel better. It is this connection between the terms "placebo" and "inauthenticity" that has come forward and stigmatized the current day notion of the placebo effect.

But let's look into this connection. Is it actually true that the placebo response is an inauthentic form of healing? Recent research on the placebo effect indicates that for many people, the simple act of believing (a mental condition) a therapy or medication will increase their health or eliminate disease is sufficient to create physical improvements in their body. This implies that our thoughts are not simply making us feel better, but they can change our brain and physiology.

One area of study includes the effects of placebo medications on pain. Tor Wager and colleagues at the University of Colorado compared the physiological changes in the brain due to a placebo vs. pain medication, and found that if persons believed they were receiving pain medication, it could produce specific and measurable physiological activity within the brain's pain pathways. This included reduced activity in the thalamus, insula, and anterior cingulate cortex, which are associated with the feeling of pain. Thus the belief that you are taking pain medication can have a similar effect to taking the medication itself.

These effects apply to other drugs as well. For example, a review of randomized controlled trials (the gold standard of research design) in which patients were given either antidepressants or placebos, showed that approximately 75 percent of the effectiveness of antidepressants was due to the placebo effect.

As a neuroscientist who works with patients with neurological diseases, including Parkinson's disease, I was surprised to discover that placebo drugs even had a positive effect on health in some Parkinson's patients. A study comparing the effect of a placebo vs. the drug L-Dopa found that both caused an increase in the release of endogenous dopamine and improvements in motor skills. In effect, when taking a placebo, the patients' mind/belief system improved nervous system function and reduced the effects of the disease.

How can this happen? Edward Kelly, a neuroscientist at the University of Virginia, in his book Irreducible Mind notes that most scientists avoid the problem of how our subjective mind, or consciousness, could act on the objective physical body. He suggests that we cannot answer this question within the materialist framework of our medical system.

The results of the above research and other studies lead me to the conclusion that our beliefs can have a significant effect on our health and well-being. I believe that many complementary medicine therapies take advantage of the understanding that mental beliefs and thoughts can affect our physical well-being.

Studies from my own lab and those of other scientists have shown the positive effects of meditation on our mental ability, including improvements in both attention and immune function. Brain areas positively affected by meditation include the hippocampus, which affects learning and memory, and the amygdala, which controls the flight or fight response. People who meditate are thus better able to learn and less likely to be stressed by events in their lives. This is in spite of the fact that nothing changes in the person's environment.

How can this be? I propose that this is due to the powerful influence of what we have dismissed as the placebo effect. Rather than being pejorative, the term "placebo effect" reflects the powerful effect the mind has on the body. The placebo effect is a part of the potent effect of both Western and complementary therapies, reflecting the influence of our consciousness, our mental beliefs, on our physical bodies. I propose that the placebo effect will eventually be explained within a scientific framework, but first that framework must be expanded to include the possibility that something as intangible as one's belief can directly alter the structure and function of the body. Until we can disassociate the term "placebo" from the concept of inauthenticity, we need a different term to capture the construct of mind-body interactions in healing.