Inflammation in the body may be associated with depression, but until recently, the evidence was confusing. Now, a study has looked at symptoms of depression separately, and has found that certain symptoms associated with depression are also correlated with systemic inflammation.
Common symptoms of depression that are classified as physical: “changes in appetite”, “felt everything was an effort”, “loss of energy”, and “sleep problems”; and one cognitive symptom: “little interest in doing things” are associated with systemic inflammation, while other symptoms of depression are not.
The results are also consistent with recent findings of a relationship between chronic depression, low level inflammation and the metabolic syndrome, specifically weight gain. The association appears to go both directions. Chronic depression increases the odds of weight gain and inflammation, and weight gain increases the likelihood of inflammation and depression.
This finding suggests that treatments for inflammation can be helpful in depression if the depressive symptoms are physical. Fish oil, and increased outdoor exercise are strongly recommended in cases of inflammation. To date, the evidence for medications that may be used in these circumstances is conflicting and not well understood.
C reactive protein (CRP) is a lab study for inflammation that we use on a fairly routine basis for patients with depression and fatigue. We are continuing to study if other tests, but generally CRP seems to give the best results.
For more information, see our page at Gateway Psychiatric Services here.