Chronic pain is a widespread health problem. A new review by NCCAM researchers in Nature Reviews Neuroscience looks at recent research on pain and the brain. It suggests that chronic pain affects the anatomy of the brain and impairs certain nerve pathways, leading to a “negative feedback loop” that results in more pain and accompanying emotional and reasoning problems. Many people affected by chronic pain are becoming more aware of how the mind can control the body, and are adopting practices such as meditation and yoga to reduce stress and control pain.
Pain is a complex experience that varies greatly among people and within individuals. The many reasons for this variation include individuals' emotional and cognitive states, their expectations, and the contexts and meanings that surround their pain. Scientific understanding of this area, including an understanding of the pain modulatory systems in the central nervous system and the brain, has been growing. Cognitive processes (such as attention and focus) and emotional processes are part of those modulatory systems, and they affect the pain experience differently.
The evidence has been building that chronic pain can alter the functioning and anatomical integrity of various brain regions. This can lead, for example, to accelerated loss of gray matter, increased sensitivity to pain signals, reduced ability of the brain to release its own painkillers, emotional changes (such as anxiety disorders and depression), and cognitive deficits. However, some animal and human studies have found that when chronic pain is successfully treated, such brain effects may be reversible.
Mind and body approaches are of interest because, similarly to chronic pain, they involve cognitive (for example, focusing attention in meditation) and emotional factors. Evaluating the available research, the authors found growing evidence that mind and body practices may reduce acute and chronic pain. In addition, some studies suggest that mind and body practices could help reverse chronic-pain-associated brain changes and may have protective effects. The authors noted that further study is needed for confirmation, however, including laboratory research and studies in chronic-pain patients.
- Bushnell MC, Čeko M, Low LA. Cognitive and emotional control of pain and its disruption in chronic pain. Nature Reviews Neuroscience. May 30, 2013. Epub ahead of print.