Only about half of those with depression respond to anti-depressant medications. Researchers are trying to improve those odds by better understanding the mechanisms that cause this illness.
University of Pennsylvania scientists now are investigating a potential link between inflammation and depression — since there’s evidence that people with depression have higher rates of inflammation in both their blood and their brains.
The research team at the Center for Neuromodulation in Depression and Stress has zoomed in on interleukin 6, a protein secreted by the body to fight infection.
At normal levels, it’s a good thing; elevated levels, however, have been shown to cause depression in animal studies — and in humans during cancer treatment. “If you induce high levels artificially with interferon, which is a treatment for cancer, then about a quarter of people who have never had depression before get depressed,” said Yvette Sheline, who heads the center.
Her current study is investigating how exactly interleukin 6 contributes to depression. “What it actually does, it degrades serotonin, which is one of the neurotransmitters involved in depression,” she explained.
Sheline says study participants will receive both an anti-depressant and an anti-inflammatory.”So people will first get treated with an anti-depressant, and we’ll see if that lowers the amount of inflammation they have and lowers their depression,” she said. “And then, in the second step, we will add in an anti-inflammatory agent, and see if that gives them an improved treatment response.”
Elevated levels of interleukin 6 are often found in the elderly, and in people who have heart disease, diabetes or are obese, Sheline said.