I’ve suffered from migraines my whole adult life—two day-long affairs that I would slog through with an unwise amount of cumulative Advil. Until, that is, a neurologist offered me a calcitonin gene-related peptide (CGRP)-inhibitor, the first new pain treatment in decades. It’s solved the problem with a decisiveness I would never have thought possible.
For chronic pain sufferers, there has yet to be an equivalent. Addressing Ottawa’s premier parliamentarians’ science lecture, Bacon & Eggheads, McGill University’s Dr. Jeff Mogil explained that everyone with chronic pain has nerve damage or inflammation somewhere, but the pain itself seems activated by psychological factors—catastrophizing, perseverating, depression and anxiety.
Most of what we give people to treat chronic pain amounts to a placebo, but the good news is what feels like it will be a problem forever rarely is. For example, the average duration of chronic back pain is between three and five years before it spontaneously remits (resolves by itself).
So what’s with this powerful psychological component? Some lines of evidence are emerging that whisper a potential adaptive value for what seems like such a pointless waste of a sufferer’s attention and energy. Whereas acute pain is for limiting tissue damage (take that hand off the stove!) and medium-term pain serves to punish movement after an injury, where immobilization aids healing, there may be an ancient reason we feel chronic pain, anxiety, and depression in response to inflammation.
When we’ve had inflammation, the theory goes, our body knows it’s not running at 100%, and it is less likely to evade or escape an encounter with a predator, so chronic pain produces hypervigilance to predation. Meanwhile, there are few associations so well established in the psychiatric literature as that between inflammation and depression. How better to stay away from predators in your compromised state than to take to your bed?
While not much works, exercise seems to be the most effective treatment, though it’s exactly what you don’t feel like doing when you’re in pain.
And as for that old trope about women having more pain tolerance because of childbirth, Dr. Mogil laid out a thorough case for the opposite. The more body parts men have pain in, the faster they die. This is not true for women, but women are far and away more pain sensitive and more likely to be suffering from it at any given moment.
The future of the field looks brighter, as Americans put in place a policy in 2016 to balance out their lab animals’ sex ratios. The biology of pain is quite different in each sex, and it hasn’t helped to have middle-aged women modeled by young male rats. Some blockbuster effects are already coming out of the research into the gut-brain axis, and Dr. Mogil points out this means a lot of the genes affecting pain are actually bacterial genes.
Meanwhile, I get to enjoy the greatest pain innovation since the first midwife boiled willow bark thousands of years ago. It looks like endometriosis might also benefit from the same molecule that saved me from my head-clutching existence. Based on my former migraine patterns, I calculate I’ve been gifted about 12% of my time on this Earth back.
Time to venture out from the cave and waltz among the predators.
Categorized in: Miscellaneous