Pain and the Brain

Orthopaedic & Spine Center

Andrew L. Martin, PsyD

We still have a lot to learn about the complex relationship between pain and the brain, but our understanding is improving. My colleagues, Drs. Jenny Andrus and Raj Sureja are addressing the physical aspects of pain in a series of articles they are currently writing. I’d like to provide some insight on a psychological level.

PAIN PATHWAY. Pain signals go from nerve endings, to nerve branches, to the spinal cord, and then up to the brain – but that last step is complicated. Pain signals take multiple paths from the spinal cord into the brain’s pain centers, and sometimes the brain interferes with those signals by sending chemical messengers that turn the pain up or down. Over time, the brain can even grow more cells for detecting and experiencing pain, thus turning up the pain signal. Brain centers that involve thoughts and emotions also act on pain signals entering the brain, and are so powerful they can eliminate pain, or turn the signal way up1. The brain clearly has something to say about how much pain we feel.

EXAMPLES. On one level, we’ve always known that pain is about more than just bodily injury. For example, when we’re in a good mood or distracted, we notice our pain less – and when we’re stressed, we feel the pain more. Laboratory research backs this up. For instance, when people are told they are receiving a pain medication, they report feeling less pain, whether or not they were actually given a pain medication3. And people who are taught mental skills to cope with pain also report feeling less pain, whether or not they actually use those skills1.

In a famous case study from World War II, US soldiers injured in a European town knew their injuries meant they were going home, and they reported little pain and required little pain medication. The local residents who were injured however, had to stay in the war zone, and reported much more pain and required much more pain medication2. Stressful life circumstances had a significant impact on the pain experience.

WHAT WE CAN DO ABOUT IT. Although we don’t understand this process completely, we’ve learned enough now for psychologists to help manage chronic pain. Psychologists help people develop skills to reduce pain, or “narrow the gate” for pain signals traveling from the spinal cord to the brain. Cognitive behavioral therapy for chronic pain is the most common such treatment, and is shown to help about 70% of people with chronic pain to feel less pain, experience fewer pain flare-ups, and get a lot of their life back that chronic pain took away. It’s even powerful enough to reverse chemical and structural changes in the brain caused by chronic pain1.

THERE IS HOPE. So does this mean the pain is “all in our heads?” No – at least not the way it’s often meant. I believe people’s pain is real, and its severity depends on factors that we can’t naturally control. But with education and practice, we can gain more control, and significantly influence pain. Look how complicated the brain’s relationship is with pain. That can’t all be observed in an MRI, so nobody can tell me my pain isn’t “real,” especially if they’re just looking for bodily damage.

TREATMENT EXAMPLE. If the mind perceives chronic pain as a threat, it activates the “fight or flight” response, the natural reflex response to danger, which increases blood and oxygen flow, stops digestion, and gets the body ready to fight or run away. Muscles tense (which worsens pain), and fear and frustration develop (also worsening the pain). The senses all heighten, and focus solely on the “threat (pain).” This means the brain is opening the door wide to all pain signals, and focusing almost entirely on those signals. This is helpful if the threat is a grizzly bear, but not if it’s chronic pain.

If the mind instead thinks of chronic pain as a challenge (this can be done with practice), then the nervous system needn’t go into “fight or flight” mode each time the brain notices pain. The brain realizes it does have the ability to survive this event, so the chronic pain remains a background irritant, versus a front-and-center threat. This prevents several pain-related processes from ever happening. Since most of our pain-related thoughts are out of our awareness, it takes a little practice to identify and change them, but it can be done!

Pain is “real.” You are not your pain. You are not alone. There is hope.

1Thorn, B. E. (2017). Cognitive therapy for chronic pain: a step-by-step guide. Guilford Publications.

2Beecher, H. K. (1959). Measurement of subjective responses: quantitative effects of drugs.

3Bingel, U., Wanigasekera, V., Wiech, K., Ni Mhuircheartaigh, R., Lee, M. C., Ploner, M., & Tracey, I. (2011). The effect of treatment expectation on drug efficacy: imaging the analgesic benefit of the opioid remifentanil. Science translational medicine3(70), 70ra14-70ra14.