Depression research has become something of a downer. The first drug to ease the torments of those afflicted with the disorder hit the market more than half a century ago, and since then dozens more have emerged. All essentially operate on the same elements of brain biology - the neurotransmitters serotonin, norepinephrine, and dopamine - and for many people, they work quite well. Yet none has altered the stubborn fact that one-third of patients don't get better no matter how many meds they try. With 16 million Americans estimated to have suffered a major depressive episode in the past year according to the National Institute of Mental Health, that adds up to a lot of unmitigated suffering, and a lot of psychiatrists frustrated by their inability to help.
Enter inflammation, which has been associated with depression since at least the 1990s, although the nature of the connection has been unclear and the research focus on it marginal. "It never had enough traction to grab the field's attention," says psychiatrist Dr. Andrew Miller, faculty member in Neuroscience.
That may be changing. For five years, research on inflammation and depression has been accelerating, pulling it from the periphery into the spotlight, and the pace has increased markedly in just the past year. Although there's still no tidy illustration of how the two conditions are linked, there's a growing confidence that inflammation has a significant role in the depression equation. In a field that Dr. Miller describes as being at "a crisis point looking for new ideas and conceptual frameworks that might yield more effective treatments," emerging findings about inflammation have been received "like the Second Coming."