Diagnosing a patient with clinical depression can be difficult; depression is a complex illness that can be caused by one or a mix of many things, from environmental stressors to genetics. But a new study out of the Centre for Addiction and Mental Health (CAMH) has highlighted a link between clinical depression and brain inflammation that might be crucial in better understanding stress and depression’s physical impacts on the body, as well as in developing better treatments for these mental health issues.
In the study, published in JAMA Psychiatry, the researchers found that people with clinical depression had a 30 percent increase in brain inflammation, also referred to as neuroinflammation. It’s uncertain whether the inflammation caused the depression or vice versa, or if it’s simply a correlation. But the study makes it clear that the link should be further examined.
“This finding provides the most compelling evidence to date of brain inflammation during a major depressive episode,” Dr. Jeffrey Meyer of CAMH’s Campbell Family Mental Health Research Institute said in the press release. “Previous studies have looked at markers of inflammation in blood, but this is the first definitive evidence found in the brain.”
The authors took brain scans of 20 patients who were suffering from depression but were otherwise healthy, as well as of 20 control patients. They found that people with depression were more likely to suffer a higher rate of inflammation in their brains, and people with the most severe depression had the highest rates of all. While inflammation can protect the brain and other tissues when triggered by the immune system, too much of it can cause damage.