Brain Inflammation Triggered by Chronic Pain and Depression

In a study recently published in The Journal of Neuroscience, scientists from UC Irvine and UCLA found a link between brain inflammation and chronic nerve pain, suggesting that a direct biophysical link exists between long-term pain and the depression, anxiety and substance abuse that is common in these patients. About a quarter of Americans suffer from chronic pain, making it the most common form of enduring illness for those under the age of 60. In the mouse-model study, the research team discovered that pain-derived brain inflammation causes the accelerated growth and activation of the immune cells, microglia, which trigger chemical signals within neurons that restrict the release of dopamine. However, treating the animals with a drug that inhibits microglial activation later restored dopamine release and reward-motivated behavior. “For over 20 years, scientists have been trying to unlock the mechanisms at work that connect opioid use, pain relief, depression and addiction,” noted the lead research of the study. “Our findings represent a paradigm shift which has broad implications that are not restricted to the problem of pain and may translate to other disorders.” To read more about this study, click here.