The Depressing News About Antidepressants

The Author Points Out:

But the question of whether antidepressants—which in 2008 had sales of $9.6 billion in the U.S., reported the consulting firm IMS Health—have any effect other than through patients' belief in them was too important to scare researchers off. Proponents of the drugs have found themselves making weaker and weaker claims. Their last stand is that antidepressants are more effective than a placebo in patients suffering the most severe depression.

The serotonin-deficit theory of depression is built on a foundation of tissue paper. How that came to be is a story in itself, but the basics are that in the 1950s scientists discovered, serendipitously, that a drug called iproniazid seemed to help some people with depression. Iproniazid increases brain levels of serotonin and norepinephrine. Ergo, low levels of those neurotransmitters must cause depression. More than 50 years on, the presumed effectiveness of antidepressants that act this way remains the chief support for the chemical-imbalance theory of depression. Absent that effectiveness, the theory hasn't a leg to stand on. Direct evidence doesn't exist. Lowering people's serotonin levels does not change their mood. And a new drug, tianeptine, which is sold in France and some other countries (but not the U.S.), turns out to be as effective as Prozac-like antidepressants that keep the synapses well supplied with serotonin. The mechanism of the new drug? It lowers brain levels of serotonin. "If depression can be equally affected by drugs that increase serotonin and by drugs that decrease it," says Kirsch, "it's hard to imagine how the benefits can be due to their chemical activity."

Wider recognition that antidepressants are a pharmaceutical version of the emperor's new clothes, Kirsch says, might spur patients to try other treatments. "Isn't it more important to know the truth?" he asks. Based on the impact of his work so far, it's hard to avoid answering, "Not to many people."