Chronic pain does more than hurt the body. It changes the brain in lasting ways, affecting emotions, memory, and thinking.
When pain lasts for months or years, it lights up parts of the brain like the amygdala. This area handles fear and feelings tied to pain. Studies show this activation happens in both short-term and long-term pain, especially in the laterobasal amygdala. People with chronic pain often remember pain as worse than it was. This comes from changes in the hippocampus, a brain area for memory, including less new cell growth there.
Genes play a big role too. Research on over a million people found that chronic pain links to certain genes in brain cells called glutamatergic neurons. These cells are in the cortico-limbic circuit, which includes the prefrontal cortex, hippocampus, and amygdala. This circuit shapes how we feel pain emotionally and think about it. The brain does not just sense pain. It remembers it, expects it, and adds feelings to it.
Pain also hits sensory nerves outside the brain, like C-fibers in the dorsal root ganglia. These connect to brain areas, creating a loop that keeps pain going. Genes like BSN, NCAM1, and NRXN1 help link the body and brain in this process.
Over time, ongoing pain speeds up brain aging. It leads to faster thinking decline and damage to brain cells, partly through proteins like amyloid beta. In one study, middle-aged and older adults with moderate to severe chronic pain showed brains that looked older on scans. This matches findings in low back pain and migraine patients, where pain takes mental energy away from focus and tasks.
Not all news is bad. Healthy habits can protect the brain. A study of adults aged 45 to 85 found that those with good lifestyles, even with chronic pain, had brains up to eight years younger than their real age. These habits kept brains looking younger over two years. As people age, joints and tissues wear down, raising pain risk, but positive routines help.
Genes affect neuron growth and connections too. In brain areas like the cortex and in pain nerves, these changes explain why pain sticks around. Drugs that reach the brain might help fix this by targeting those spots.
Sources
https://pmc.ncbi.nlm.nih.gov/articles/PMC12700546/
https://www.jci.org/articles/view/200554
https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/alz70862_109861
https://www.medicalnewstoday.com/articles/5-healthy-habits-may-help-keep-the-brain-younger-even-with-chronic-pain
https://academic.oup.com/braincomms/advance-article/doi/10.1093/braincomms/fcaf486/8376909?searchresult=1
