Map of life expectancy at birth from Global Education Project.

Tuesday, February 26, 2008

Prozac may finally shut up

I claim no psychic powers. I've been telling y'all for years now that antidepressants basically don't work. The drug companies have been promoting the fiction that depression is a specific disease of the brain caused by a "chemical imbalance," specifically a deficiency of the neurotransimtter serotonin, which their potions -- Prozac, Zoloft, etc. -- purportedly cure. It's all nothing but a big pile of crap.

Irving Kirsch and colleagues, in PLOS Medicine, tell us what shakes out when you look at all the RCTs that have been done on these "medications," including the ones the drug companies made sure not to publish. Naturally, the ones they didn't publish are the ones that show their products in the worst light.

The discussion of this analysis is a bit complicated for those of you who haven't studied a lot of statistics, but the bottom line is simple enough to explain. It's essentially what I have been telling you all along. There is a very large response to placebo in depression. For only a small minority of people is the response to antidepressants any better than the response to placebo, and even in those cases, generally speaking, the response is of no clinical significance. (Response is defined as how people answer a questionnaire called the Hamilton Rating Scale for Depression -- which you can like or not like as a definition of "disease.")

Kirsch et al confirm all this -- which has been widely reported in the United Kingdom but has not made it past the curtain of censorship here in the U.S. What they add to the picture is that SSRIs are of essentially no use whatsoever in people with moderate to severe depression. The small advantage only appears in people with the most severe depression as measured by the HRSD. Those are a very small minority of all people who are diagnosed with depression and who are prescribed SSRIs. The reason the drugs show some advantage with those people is because they don't respond as strongly to placebo as people with less severe depression, not because the SSRIs are more effective. The benefit, while on average above the threshold defined by the U.K.'s NICE* as clinically significant, is still pretty small.

So please ignore those TV ads. If you're feeling sad, or down, or blue, or depressed, or whatever you want to call it, one treatment which has been proven to work with many people is exercise, which is good for you anyway. If it still doesn't work, cognitive behavioral therapy has also been shown to work well for many people. That's a kind of counseling to help people redirect their thinking and behavior in more positive ways. And the outcomes are better than anti-depressants in the long run. As Kirsch et al suggest, SSRIs should be considered only in people with very severe depression, and perhaps in people with somewhat less severe depression for whom other treatments have failed. I'm convinced.

Billions of dollars are wasted every year on these worse then worthless compounds -- they can have serious side effects, and they are addictive. Instead of handing them out like lollipops, doctors should think of them as more like morphine -- only for the desperate.

*I've written about this agency many times here. One of Barack Obama's proposals for containing health care costs is to establish a U.S. equivalent -- an institute that will judge the cost-effectiveness of treatments, providing guidance to insurers on whether to cover them.

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