Chronic pain, depression, and the brain
You know you’re a geek when you unwind at the end of the day while listening to a lecture on the role of microglia in central sensitization and depression… Here’s a little outline of the lecture.
How does chronic pain work?
Some chronic pain, especially chronic pain syndromes, seems to stem from central sensitization. Central sensitization happens when the nervous system gets wound up and has trouble calming down, this can happen short-term or turn into a syndrome. Some ways that the system can go awry include:
- Being overly sensitive and making pain signals stronger.
- Reading normal signals, like temperature or pressure, as pain.
- Firing up a bunch of nerve pathways that wouldn’t normally fire.
- Not turning off the pain signal when no longer needed.
Sometimes people feel pain even when no obvious reason exists. In some cases an obvious reason exists, but people feel a higher level of pain than one would normally expect from it. And in some instances, pain persists after healing. Of course, all of these can occur together.
What is the link between mental health and chronic pain?
Chronic pain also happens to strongly coincide with depression, anxiety, and/or PTSD. People who have chronic pain and/or one of these mental health disorders are more likely to have the other. Statistics also show that people who have both struggle more with managing and improving their conditions. Science has yet to describe exactly how the interplay works.
What are microglia?
Microglia are one of several types of brain cells. These cells take care of the immune response in the brain. They scan for potential problems and then jump into action when they perceive a threat. They can actually change themselves depending on what action is needed– scanning, repairing, removing waste, and regenerating. Just like other parts of the immune system, repetitive trauma or perceived threats can sensitize these cells so that they over work. Unfortunately, when these cells are active for too long (neuroinflammation), they can weaken the brain.
Research indicates that microglia over work in chronic pain syndromes, depression, anxiety, and PTSD (and some other neurodegenerative conditions).
So what can one do to calm this process?
As much as anyone with chronic pain or depression hates to hear it, exercise seems to help. Proper diet and the right balance of nutrients can also have a positive effect. Mind/body approaches- like yoga, meditation, and deep breathing have led to reduced neuroinflammation. Acupuncture has a few studies behind it. Of course, certain pharmaceuticals seem to help as well. Hopefully, massage will join this list, but no one has studied it yet. Overall the current thinking seems to point to an integrative approach to care.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6190863/#B2 Chronic Pain & Depression
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3609886/ Chronic Pain & PTSD
https://www.ncbi.nlm.nih.gov/pubmed/30389752 Chronic Pain & Mental Health Conditions
https://www.ncbi.nlm.nih.gov/pubmed/28943841 Microglia & Depression