There is a fascinating article in yesterday's Boston Globe about depression and what causes it. Recent thinking linked depression to a chemical imbalance, and drugs like Prozac revolutionized the treatment of depression by correcting the chemical imbalance. Or so the thinking went. But now...:
In recent years, scientists have developed a novel theory of what falters in the depressed brain. Instead of seeing the disease as the result of a chemical imbalance, these researchers argue that the brain's cells are shrinking and dying. This theory has gained momentum in the past few months, with the publication of several high profile scientific papers. The effectiveness of Prozac, these scientists say, has little to do with the amount of serotonin in the brain. Rather, the drug works because it helps heal our neurons, allowing them to grow and thrive again.
In this sense, Prozac is simply a bottled version of other activities that have a similar effect, such as physical exercise. They aren't happy pills, but healing pills.
These discoveries are causing scientists to fundamentally reimagine depression. While the mental illness is often defined in terms of its emotional symptoms - this led a generation of researchers to search for the chemicals, like serotonin, that might trigger such distorted moods - researchers are now focusing on more systematic changes in the depressed brain.
"The best way to think about depression is as a mild neurodegenerative disorder," says Ronald Duman, a professor of psychiatry and pharmacology at Yale. "Your brain cells atrophy, just like in other diseases [such as Alzheimer's and Parkinson's]. The only difference with depression is that it's reversible. The brain can recover."
What is not clear to me from reading this article is what it is that causes the brain cells to atrophy in depressed people. Alzheimer's and Parkinson's are degenerative diseases that generally take years to develop. Depression often shows up in young people. Why does this happen?
Still, this is a remarkable find. This is one of area of medicine where we have come to far in just a few decades. It wasn't that long ago when it was common for people who battle depression to accept their "melancholy" temperament as part of who they are, and for others to dismiss depression as laziness or the mark of someone who is a "problem." It just doesn't have to be this way anymore. If ever there was a miracle drug it is Prozac. I have seen it, and its medical siblings, change the lives of many people for the better. It works; it helps. And yet there is so much more to learn about how it works and how the brain works. What we learn in the years ahead can only bode well for those struggling with this life-sapping illness.