Antidepressants ‘no better than placebo’

In all but the most severely depressed patients, there is no evidence that new-generation antidepressants work any better than placebos. So says a large metanalysis that combed through 47 published and unpublished studies on several Selective Serotonin Re-uptake Inhibitors (SSRIs), published in PLoS Medicine yesterday. This class of drugs includes Prozac.

The bold headline ‘Antidepressants don’t work’ obviously caught the attention of the press (Google news search yields at least 250 hits today; almost all from the UK) and the public, and for good reason. It’s important to keep in mind that professionals already knew these drugs don’t have a huge effect for many (more below). But the extent to which the drugs were found to be effective as a placebo is striking. They did seem to work in extreme cases, but not for the reason one would expect: “The main finding among severely depressed people was that they ceased to respond to a dummy placebo pill, not that they showed a particularly heightened response to anti-depressants." (BBC)

Current UK National Institute for Health and Clinical Excellence (NICE) guidelines already advise non-medicinal treatments for mild depression, including exercise and sleep management or psychological interventions. “Antidepressants are not recommended for the initial treatment of mild depression, because the risk–benefit ratio is poor,” they state. “Where mild depression persists after other interventions, or is associated with psychosocial and medical problems, consider use of an antidepressant.”

As Anne Robinson tells us in a Guardian post, there is “no need to panic”. “People who are already on antidepressants and getting better should stay on them and then tail them off gradually when they feel ready. Those who are considering taking them will want to think twice. But none of that’s new and none of it is reason to panic.” This ‘not new’ statement sits rather ironically aside the Guardian’s choice for front page.

It’s with moderate depression that the case gets interesting. NICE guidelines say: “In moderate depression, offer antidepressant medication to all patients routinely, before psychological interventions.” It is unclear whether that should now be changed. Lead study author Irving Kirsch from the department of psychology at Hull University, who was one of the consultants for these guidelines, says the new analysis suggests prescriptions “might be restricted even more” (Guardian).

(see UPDATE below the fold)


The news illuminates two worrying trends: the vast over-prescription of drugs such as antidepressants, and the vast quantity of unpublished data on drugs that often never sees limelight.

The Telegraph’s Q&A tells us the number of prescriptions written for anti-depressants has tripled in 15 years; perhaps more because of over-diagnosis and over-reliance on drugs than because of any upswing in unhappiness.

And as always, the fact that drug companies are not obliged to publish negative results remains a worry. From the Telegraph again: “Drug companies have to submit all their clinical evidence to drugs watchdogs in order to gain a licence but they do not have to publish negative results to the wider medical community.” The researchers in this instance used the Freedom of Information Act to get their hands on more data from the US FDA.

The main comments against this metanalysis are generally from drug companies or industry reps, as here, from the BBC:

Dr Richard Tiner, of the Association of the British Pharmaceutical Industry, said there was no doubt that was a “considerable placebo effect” from anti-depressants when treating people with mild to moderate symptoms. But he said no medicine would get a licence without demonstrating it was better than a placebo. Dr Tiner said: “These medicines have been licensed by a number of regulatory authorities around the world, who looking at all the evidence, have determined that they do work better than placebo.”

To me this simply begs a question: how much better than placebo does a drug need to be, and in how many people, for it to be licensed?

From the archive:

All our previous stories on antidepressants.

UPDATE: The Guardian has gone big with this story, again, today:

Ben Goldacre, ‘bad science’ columnist, hits the issue of drug regulation hard.

Psychoanalysts trace the history of Prozac in this lengthly mental health piece. And, in news, they look at a big UK push to give money money to psychoanalysts (an alternative to drug treatment for depression).

Leave a Reply

Your email address will not be published. Required fields are marked *