Targeting inflammation to treat depression
Researchers at Emory have found that a medication that inhibits inflammation may offer promise for people with difficult-to-treat depression.
Prior studies have suggested that depressed people with evidence of high inflammation are less likely to respond to anti-depressant medications and psychotherapy. This study was designed to see whether blocking inflammation would be a useful treatment for people with difficult-to-treat depression or only those with high levels of inflammation.
The study employed infliximab, used to treat autoimmune and inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease. Infliximab blocks tumor necrosis factor, a key molecule in inflammation that has been shown to be elevated in some depressed people.
Study participants all had major depression and were moderately resistant to conventional antidepressant treatment. Each participant was assigned either to infliximab or to a non-active placebo treatment.
When investigators looked at the results for the group as a whole, no significant differences were found in the improvement of depression symptoms between the drug and placebo groups. However, when the subjects with high inflammation were examined separately, they exhibited a much better response to infliximab than to the placebo. Inflammation in this study was measured using a simple blood test that is readily available and measures C-reactive protein.
"The prediction of an antidepressant response using a simple blood test is one of the holy grails in psychiatry," says Andrew Miller, senior author of the study and the Timmie Professor of Psychiatry and Behavioral Sciences. "This is especially important because the blood test not only measured what we think is the root cause of depression in these patients but also is the target of the drug."
