We already know that inflammation is a likely cause or contributor to nearly every disorder and disease known to man.
The word inflammation comes from the Latin “inflammo”, meaning “I set alight, I ignite”. Inflammation sparks your immune system into action in an attempt to protect you from harm. It is part of a complex biological response to damaging stimuli, including injuries, pathogens, and irritants. Inflammation is NOT an infection, but can it be caused by infection.
Acute (short-term) inflammation is usually a good thing. The swelling, heat, redness, and pain you feel after an injury or during an infection are signals that your immune system is doing its job by firing up the inflammatory process, which begins healing and reminds you to care for the affected area.
But chronic (long-term) inflammation can result in serious health issues including asthma, autoimmune diseases, arthritis, Crohn’s, colitis, celiac disease, periodontitis, rheumatoid arthritis, and some cancers.
About 20 years ago, researchers started noticing that the levels of cytokines and T-cells, (which help drive immune responses and secrete cytokines), were higher in blood samples from people diagnosed with depression.
Many studies and observations that followed support the link, and a new study appears to confirm it.
Researchers at Rice University and Ohio State University reviewed 200 existing papers on depression and inflammation and concluded that “chronic inflammation in the bloodstream can ‘fan the flames’ of depression, much like throwing gasoline on a fire.”
The paper, titled Inflammation: Depression Fans the Flames and Feasts on the Heat appeared in a recent edition of the American Journal of Psychiatry.
Christopher Fagundes, an assistant professor of psychology and co-author of the paper, said of the study:
In the health area of psychology at Rice, we’re very focused on the intersection of health behavior, psychology and medicine. One thing that we’re particularly interested in is how stress affects the immune system, which in turn affects diseases and mental health outcomes, the focus of this paper.
The authors found that in addition to being linked to numerous physical health issues, including cancer and diabetes, systemic inflammation is linked to mental health issues such as depression. Among patients suffering from clinical depression, concentrations of two inflammatory markers, CRP and IL-6, were elevated by up to 50 percent.
Chronic inflammation is most common in individuals who have experienced stress in their lives, including lower socio-economic status or those who experienced abuse or neglect as children, Fagundes said. Other contributing factors are a high-fat diet and high body mass index.
Previous research shows that individuals who have socio-economic issues or had problems in their early lives are already at higher risk for mental issues because of these stresses in their lives. As a result, they often experience a higher occurrence of chronic inflammation, which we have linked to depression.
He said that it is normal for humans to have an inflammatory response – such as redness – to an area of the body that is injured:
This is your immune system working to kill that pathogen, which is a good thing. However, many individuals exhibit persistent systemic inflammation, which we’re finding is really the root of all physical and mental diseases. Stress, as well as poor diet and bad health behaviors, enhances inflammation.
Fagundes said that a strong support system early in life is critical in helping individuals learn to deal with stress later in life.
Fagundes hopes the study will shed light on the dangers of bodily inflammation and the steps that can be taken to overcome this health issue:
We still have a lot to learn about how inflammation impacts depression, but we are making progress. We hope one day this work will lead to new treatments that are part of standard psychiatric care.