The Stoic Lucius Seneca once wrote: "It is part of the cure to want to be cured."

This simple observation reflects our current understanding of the relationship between mind and body. There is a close correlation between physical actions and mental states. Certain actions can impact our mental attitudes and our mental attitudes influence our physical being because the mind and body constantly talk to one another. The brain sends all that it thinks and perceives to the rest of the body.

An extreme example of this interconnection can be seen in the effects of voodoo. In the 1940s, Harvard physiologist Walter Cannon spent several years collecting examples of "voodoo death" -- case histories of men and women who died as a result of being the recipient of a curse, an alleged supernatural visitation or the breaking of some tribal or cultural taboo. Cannon concluded that humans could die from "the fatal power of the imagination working through unmitigated terror." Another researcher, Dr. J.C. Barker, in Scared to Death -- a collection of case histories of individuals who had willed themselves or others to death -- concluded that voodoo-like death results "purely from extreme fear and exhaustion...essentially a psychosomatic phenomenon."

How is it possible for thoughts to impact the body so drastically?

It is possible because the central nervous system and the body's immune system are hard-wired together. In 1981 neurobiologist David Felten and a team of researchers at the Indiana University School of Medicine found the first concrete example of the mind/body connection -- a bridge between the body's immune system and the central nervous system that is under control of the brain. While tracing nerves to bone marrow, lymph nodes and the spleen, Felten's team discovered a network of nerves leading to blood vessels as well as to cells of the immune system. They found that nerves in the thymus and spleen terminated near clusters of lymphocytes and mast cells, which help control immune function. In other words, the brain absolutely communicates with immune-system cells.

This establishes a close correlation between a person's mental state and physical reactions. You can generate an emotion simply by going through the appropriate muscle movements. For example, if you clench your fist and scowl, you will begin to feel anger. Force yourself to laugh and you will begin to feel good. The specific muscle action is an integral part of the corresponding emotion. You cannot hold your features in the expression of one emotion and call up the feeling of a different emotion at the same time. It is impossible to do.

Paul Ekman, Professor Emeritus at the University of California at San Francisco, is a pioneer in the study of emotions and facial expressions. His research on more than 200 kinds of smiles demonstrated that you could actually alter your emotional state and immune system by smiling or frowning. When Ekman's research subjects were trained to control their facial muscles and voluntarily form smiles, their physiological processes altered immediately and their hormones changed drastically.

So when you smile, you alter your blood chemistry. The natural opiates in your system and your neuropeptides change. These chemicals are located not only in your brain but in your stomach and intestines.

What does this have to do with hypnosis?

Hypnosis is the most powerful tool we possess for changing thoughts and attitudes. It is a trance state characterized by relaxation, extreme suggestibility and hyper-attentiveness. The subject is fully conscious, but chooses to focus internally while ignoring external stimuli.

Hypnosis allows one to access the subconscious mind directly. In this relaxed, hyper-attentive state, the subject experiences the hypnotist's suggestions as if they were real. If told that his or her tongue has swollen to double its normal size, the subject will have difficulty talking. If told that his/her hands are glued together, the subject cannot pull them apart. By the same token, the subject is receptive to suggestions that are designed to change destructive thought patterns and habits such as anxiety, depression, stress, smoking and eating disorders.

A potent example of hypnosis' power to affect physiology through the brain connection is its medical use. Since all pain is transmitted through the brain, the pain associated with surgery or medical conditions responds well to hypnosis. Hypnosis is an effective anesthesia for surgeries, dental procedures, childbirth and migraines. It also helps patients to manage nausea and symptoms from chemotherapy by enhancing control over their body responses.

The mind/body connection is the key to why hypnosis can be used so successfully to manage our physiology. Hypnosis gives us the power to alter our mental attitudes for the better; this in turn positively impacts our physical being.

In light of this potent interplay between mind and body, we would do well to take seriously the old Cole Porter song: "Accentuate the positive; eliminate the negative; latch on to the affirmative." And enjoy happy body chemistry as your reward!