Monday, October 27, 2008

Audio: The rise of therapeutic nihilism about depression

Therapeutic nihilism - the belief that we have no effective medical cures at all, or no cure for some condition - has recently arisen about clinical depression. Most famously, University of Hull professor Irvin Kirsch and colleagues argued in a recent meta-analysis published in PLoS Medicine that, when previously unpublished data are taken into account, there is no evidence that antidepressants have clinically significant benefits over placebo. (It is important to note that there is a strong placebo effect, so in a sense we do have a somewhat effective remedy - it's just not pharmacological).

The 36th Maudsley Debate (mp3 here), held at King's College London, considered this question in the form of the motion "This House Believes Antidepressants are no Better than Placebo." Irvin Kirsch and Joanna Moncrieff (of University College London) argued for the motion and Lewis Wolpert (of King's College) and Guy Goodwin (of Oxford) against. From my lay perspective, Kirsch won the debate hands down. While I thought Goodwin raised a bunch of interesting methodological points, I don't think they were decisive and he did commit several fallacies (the appeal to consequences, most prominently). Moncrieff's argument, on the other hand, was rather weird and somewhat beside the point. And Wolpert, I thought, was pretty bad: he was impassioned and entertaining, to be sure, but his substantive argument was shot through with fallacies and factual inaccuracies.

In any case, give the debate a listen. What do you think?

(Via The Mouse Trap).


  1. Hey Michael,

    I haven't managed to listen to the Maudsley debate yet - I keep putting it off - but this is a topic which I know quite a bit about.

    My personal view is not therapeutic nihilism but rather therapeutic skepticism. I think we just don't know how well treatments work in depression. If you read the literature (as I do - it's my job) you quickly come to feel that although there is a huge amount of evidence, it all adds up to very little actual understanding. Hence why opinions range so widely from Moncrieff all the way to Goodwin.

    The problems with studying depression are many but they include: the difficulty of diagnosing depression, and hence finding appropriate research subjects;

    the difficulty in rating the severity of depression (there are various pen-and-paper ratings scales but they're all seriously flawed, as Irving Kirsch has pointed out elsewhere amongst many other people.)

    and the fact that almost all trials last 6 weeks or less whereas in the real world people generally take antidepressants for months or years. Yet the placebo-controlled literature on long-term antidepressant use is very limited.

    All of which means, I think, that the real world clinical effectiveness of antidepressants over and above placebo could be zero or it could be very large. From "clinical experience" I suspect it's quite large but the hard evidence doesn't really exclude any possibility.

    I think I'll write a blog post about this to elaborate further - I'll let you know when I do!

  2. Hi Neuroskeptic - thanks for your comment. I have read only bits of the literature - and I have no qualification in medicine - so I certainly know less about this than you do. But, for what it's worth, overall, I think you're right. The depressing thing (spot the pun...), though, is that it seems pretty clear that it has not been demonstrated that antidepressants have clinically significant benefits over placebo. And, of course, the onus is on the companies selling the drugs to show that they are effective.

    Oh, and do let me know if you write such a post...

  3. Hi,
    I'm not a medic either, although I work alongside a lot of psychiatrists. I'm just a humble researcher. Well, not so humble.

    You're right that the state of the evidence is depressingly bad. Although there are a few hopeful spots. I'll post about that soon.

    In the meantime, on a related topic I've just posted this which you might find interesting...