Dr. M. Catherine Bushnell
Photo: Lisa Helfert
What happens in your brain when you experience pain? Can mind-body approaches really help ease pain? Dr. M. Catherine Bushnell, scientific director of NCCAM’s Division of Intramural Research, tackled these topics when she recently spoke on “The Neural Basis of Mind-Body Pain Therapies” in NCCAM’s Integrative Medicine Research Lecture Series.
“Pain is a multidimensional, complex and individual experience,” said Bushnell, who is leading a new, cross-cutting NIH research initiative on pain. Research has been yielding fascinating insights on pain’s underlying biology. For example, imaging has shown that even in conditions in which the causes of pain are not visible or known, the brains of pain patients do experience pain. And it is evident where in the brain this happens.
When someone is exposed to a pain stimulus, a series of signals ascend from the body site to the spinal cord and then the forebrain. Then, as part of pain processing, a series of signals descend in the opposite direction. In both directions, multiple pathways and cells, such as neurons and neurotransmitters, are involved.
Signaling in the downward path can be reduced or increased, altering the person’s experience of pain. One way to do so is to employ the brain’s natural capacity to release opiates; this can be done not only through analgesic drugs but also through employing “natural” psychological processes such as attention and the emotions.
This is where mind-body approaches, which employ interactions between the brain, mind, body and behavior, enter the picture. Bushnell explained some of her team’s and others’ work in this area. Studies on hypnosis, meditation and yoga have found that these approaches seem to beneficially affect people’s perception of and tolerance of pain stimuli and alter pain processing.
Cognitive-behavioral therapy, too, appears to have these effects. Mind-body practices may also slow down the loss of brain gray matter that occurs naturally with age and is accelerated in people who have had longtime chronic pain.
The placebo effect, too, shows promise in helping to counter the effects of chronic pain, Bushnell said. For example, research has shown that expecting relief from a placebo activates a descending pain modulatory system similar to the one activated by emotions. Another intriguing area of placebo research is the role played by dopamine, a neurotransmitter important in anticipation of rewards.
Bushnell’s lecture is available online under Past Events at videocast.nih.gov.—Ellen O’Donnell