Chronic inflammation in the bloodstream can intensify depression, according to research published in the American Journal of Psychiatry.
According to Christopher Fagundes, PhD, an assistant professor of psychology at Rice University, chronic inflammation is most common in those who have experienced serious stress in their lives, such as struggling with lower socioeconomic status, having a history of abuse or neglect during childhood, or losing a spouse. Other contributing factors include having a poor diet and/or a high body mass index.
These stressors can lead to chronic, systemic inflammation, which puts individuals at risk for mental health issues, including depression. The depression feeds on the inflammation like fire feeds on gasoline, which can lead to further stress and inflammation, creating a cycle.
While it is normal for humans’ immune systems to react with an inflammatory response to an injury, such as redness in the affected area, chronic inflammation leads to problems.
“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,” Dr Fagundes said in a statement.
Researchers from Rice and Ohio State University conducted a meta-analysis of 200 studies on depression and inflammation.
They found that in addition to being tied to physical health issues such as cancer and diabetes, systemic inflammation was linked to clinical depression. In those suffering from clinical depression, two inflammatory markers, CRP and IL-6, were found to be elevated by up to 50%.
The researchers also found that depression triggered by chronic inflammation is generally resistant to traditional therapy methods, but can be treated with alternative activities such as yoga, meditation, non-steroidal anti-inflammatory drugs, and exercise.
Dr Fagundes noted that a strong support system early in life is imperative to help individuals learn to deal with stress later in life. He also hopes that the study will shed light on the dangers of chronic inflammation and what can be done to avoid it.
Dr Fagundes is launching a five-year bereavement study that will examine how inflammation impacts depression and disease among those who recently lost a spouse in the hopes that it will help find better ways to treat grieving older adults.
“We still have a lot to learn about how inflammation impacts depression, but we are making progress,” he said in a statement. “We hope one day this work will lead to new treatments that are part of standard psychiatric care.”
Kiecolt-Glaser JK, Derry HM, Fagundes CP. Inflammation: Depression Fans the Flames and Feasts on the Heat. Am J Psychiatry. 2015; doi:10.1176/appi.ajp.2015.15020152.