(Part 1 of a 4-part series)
Psych Congress cochair Charles Raison, MD, presented a session on the impact that inflammation has on mental health at the 2020 virtual Psych Congress Elevate conference. In this video, he explains the health effects of chronic increased inflammation.
Dr. Raison, a leading researcher in the field of immune-brain interactions, is the Mary Sue and Mike Shannon Chair for Healthy Minds, Children & Families; Professor, Human Development and Family Studies, School of Human Ecology; and Professor, Department of Psychiatry, School of Medicine and Public Health, University of Wisconsin- Madison. He is also Director of Clinical and Translational Research for the Usona Institute, which conducts research on the therapeutic effects of psilocybin.
Read the transcript:
Chronic increased inflammation is really one of the great health burdens of the modern world. And it's an interesting thing because it is probably something that was not part of human evolution. It's probably actually a fairly recent phenomenon.
There have been studies by a colleague of mine named Tom McDade, down in the Amazon jungle, looking at folks who are living more of a hunter‑gatherer kind of lifestyle, more of a lifestyle that humans had across evolution. Really interesting.
In those populations, people have very low rates of obesity—no obesity really—low rates of cardiovascular disease, low rates of diabetes, but they do tend to die at a younger age of infection.
What McDade did was he measured inflammation not just once in his folks, but repeatedly across time. He saw a really interesting pattern which is that, in general, if they weren't sick, their inflammation was unbelievable low. Then if they got sick, it would spike up. If they didn't die, when they recovered, it would drop down to almost zero again.
Now that's in counter‑distinction to those of us in the modern world. Many of use wander around not with the types of high inflammation that you get when you're sick—with something like COVID, say—but just with modestly high inflammation, and it tends to be chronic. It doesn't go up and down as much.
The problem is that this type of low‑level inflammation that never goes away can become very, very damaging over time. I sometimes use an analogy and say that high inflammation would be like cutting a board with a saw. It's a real, clear effect. Lower inflammation is more like getting at the board with sandpaper.
You're just rubbing, rubbing, rubbing, and you're not going to cut the board very quickly. But if you do that 24 hours a day, seven days a week for years, sooner or later, you're not going to have a board. That's what chronic inflammation does to the tissues of the body and the brain.
Inflammation is a process that evolved to keep us alive, to help us survive infection. It does that though by producing chemicals that are hot and toxic. Especially the type of inflammation that we see chronically in the modern world is not very specific.
Those hot molecules over time, they can help protect you against microorganisms, but they can also damage the heart and the brain. This is why, in our world, chronic, elevated inflammation is such a risk factor for a bunch of illnesses.
Now interestingly, chronic inflammation has been shown in many studies to predict a lot of the illnesses of old age. If you're wandering around in your younger years and middle age with this chronic inflammatory wear‑and‑tear, you're more likely to have a heart attack as you age. You're more likely to have a stroke.
You're much more likely to develop diabetes. Over time, it probably promotes obesity. Interestingly, chronic inflammation has also been shown to be a pretty robust predictor of the future development of depression, and you see this in younger people.
It's not just physical illnesses that are tied to the risks that come from this chronic inflammation that is probably a unique feature of the modern world, but it's also very, very relevant for a lot of our psychiatric, mental health conditions.