How Prozac Really Works [The Frontal Cortex]: ”
I’ve got an article in the Boston Globe Ideas section on the new science of depression:
Prozac is one of the most successful drugs of all time. Since its introduction as an antidepressant more than 20 years ago, Prozac has been prescribed to more than 54 million people around the world, and prevented untold amounts of suffering.
But the success of Prozac hasn’t simply transformed the treatment of depression: it has also transformed the science of depression. For decades, researchers struggled to identify the underlying cause of depression, and patients were forced to endure a series of ineffective treatments. But then came Prozac. Like many other antidepressants, Prozac increases the brain’s supply of serotonin, a neurotransmitter. The drug’s effectiveness inspired an elegant theory, known as the chemical hypothesis: Sadness is simply a lack of chemical happiness. The little blue pills cheer us up because they give the brain what it has been missing.
There’s only one problem with this theory of depression: it’s almost certainly wrong, or at the very least woefully incomplete. Experiments have since shown that lowering people’s serotonin levels does not make them depressed, nor does it significantly worsen their symptoms if they are already depressed.
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.
And yet, if you go to the official Eli Lilly Prozac website, the company is still peddling a cartoon version of the chemical hypothesis…
