Depression represents a very common condition in America with anti-depressants being the second most-prescribed drug class in the country. Most people recognize the cause of depression as being a “chemical imbalance” in the brain that which anti-depressant medication can treat. New research is suggesting a connection between depression and inflammation which leads to entirely different treatment recommendations and outcomes.
Depression- Perhaps More Than a Chemical Imbalance?
For years medical providers have believed the cause of depression to be a chemical imbalance of norepinephrine, serotonin and/or dopamine. The treatment for this condition has been the use of anti-depressant medications that work to correct these imbalances. The problem with this theory is that research doesn’t completely back it up. Several studies suggest that only 25 percent of depressed patients have low levels of these neurotransmitters. New research indicates that depression could be caused by some other process going on in the body. New research and a theory called “Immune Cytokine Model of Depression” suggest that depression may not be a stand-alone disease so much as an indicator of system-wide dysfunction and inflammation.
Inflammation and Depression:
New research suggests that depression may be related to inflammation and increased oxidative stress. This research has identified several specific connections between depression and inflammation.
Consider these findings:
The Science Behind the Theory
Inflammatory reactions produce chemicals called “cytokines”. Inflammatory cytokines are associated with psychiatric and neurological issues that can appear very much like the symptoms of depression. Research has also revealed that antidepressant medication has been shown to increase anti-inflammatory signals suggesting that these medications are not only working to correct chemical imbalances but also to decrease inflammation. “Psychoneuroimmunology,” a new field linking inflammation to psychiatric and neurologic symptoms yields many promising findings.
Causes of Inflammation Related to Depression
So if depression is the result of inflammation, what is the cause of the inflammation?
Stress is linked to depression; that is certainly no surprise. But what is surprising is that link between stress and inflammation. Stress can provoke the release of inflammatory cytokines which can lead to symptoms of depression.
Food and Body Weight
What we eat plays a huge role in our body’s ability to function. Unfortunately the American diet largely consists of foods that cause inflammation including white flour, sugar, bad fats, and too many chemicals , food addtiives, and preservatives. Foods that reduce inflammation include omega 3 fats, fermented foods and fermentable fiber; not typical components of the American diet.
Weight also plays a big role in the body’s inflammatory process. Obesity screams inflammation. Obese people have higher levels of inflammatory cytokines and research indicates that there is a connection between obesity and depression. Weight loss is associated with a decrease in inflammatory cytokines.
Gastrointestinal issues are also linked with inflammation, particularly issues related to intestinal bacteria and leaky gut. Both of these illnesses are associated with the release of inflammatory cytokines into the blood stream and research has linked them with major depressive disorder. Look for additional articles on this topic.
Exercise plays an important role in health. Humans were never meant to be sedentary beings. Exercise serves to prevent depression as well as invokes an anti-inflammatory response. Check out our article on “Behavioral Activation” for more information on this.
Believe it or not periodontal disease and dental caries cause chronic inflammation. Research suggests that there is a connection between depression and individuals with poor dental health.
Vitamin D deficiency is a surprisingly common occurrence in America. Research suggests a connection between low vitamin D and depression. Vitamin D serves as an anti-inflammatory so it makes sense that individuals deficient in this vitamin may be more susceptible to developing depression. Vitamin D supplementation has been shown to reduce inflammation in some cases.
Impacts of this Research
The new research linking depression and inflammation can have a profound impact on the way patients with depression are treated. If depression is viewed as being the cause of an underlying problem, inflammation, practitioners are able to expand treatments to address the root cause(s). Diet and exercise as well as evaluating dental and gastrointestinal health are all alternative suggestions to treat depression caused by inflammation.
While there are still other factors that contribute to depression (emotional, psychological, relational etc), it is still worth exploring a new explanation to an illness that is so much more than just “a chemical imbalance”.