In discussing her reaction to discovering that the placebo effect may be more powerful than we previously knew in antidepressant research, CBS’s 60 Minutes correspondent Lesley Stahl says, “I walked away really confused.”
After viewing her piece, I walked away with the same reaction.
What’s an ordinary person supposed to gain from watching this segment, boiling down decades’ worth of antidepressant research and thousands of studies into less than 20 minutes? I’m not sure.
Irving Kirsch is the Harvard researcher and psychologist who is featured prominently in the 60 Minutes’ piece that ran last night. He wrote a book a few years ago detailing the power of placebo in depression trials, The Emperor’s New Drugs: Exploding the Antidepressant Myth. So you know where his bias is — that antidepressants aren’t any more effective than a sugar pill when it comes to mild or moderate depression. (He even explains their impact in severe depression as a result of the flawed methodology of blinded drug trials.)
What wasn’t mentioned in the 60 Minutes piece, because it was opinion journalism forwarding a specific viewpoint, is that Kirsch’s research is selective. He hasn’t looked at every antidepressant study ever done (now numbering in the thousands). He only looked at the clinical trials required to gain U.S. Food and Drug Administration approval for 6 antidepressant drugs (there are over a dozen on the market).
This is important for a number of different reasons. FDA clinical trial approval studies are rarely very long, so they don’t reflect how antidepressants are prescribed in real life — for months and even years at a time. Subjects in these studies are also very much not like ordinary people, because anyone who has any other condition or health concern is often excluded from the study. They only look at people who have straight-up depression, with nothing else going on in their lives, and who are on no other medications or taking any other kind of treatment.
Last, these studies are the absolute beginning of research into these antidepressants — not the end, and certainly not the last word. It would be like looking at the effectiveness of a form of psychotherapy like dialectical behavior therapy (DBT) after its first 2 or 3 studies were published and drawing conclusions from those studies alone. You can do so, but you’re purposely blinding yourself to the decades’ worth of research that followed those first 2 or 3 studies.
Kirsch has been beating the placebo drum for years. Back in 2009, we noted in a blog about the efficacy of antidepressants that meta-analyses can never give you much of a picture of how individuals will react to a specific treatment. They also make assumptions that how researchers define things like “depression” are consistent (they should be — one of the reasons for the DSM — but they are often not), as well as how treatment is rated (measured by the same scale, remission rates, relapse rates, some other measure?).
We also dutifully reported when Kirsch published his book nearly two years ago. He indicts all placebo research in the interview we link to, suggesting no placebo research is really blinded, and that explains all positive drug effects found. In all psychiatric research that use blind drug trials.
At the end of the day, such pronouncements make me scratch my head. What is an ordinary person supposed to do with this information… Are we supposed to dump our antidepressants? Picket government for some sort of change?
Will Lesley Stahl’s husband, who’s been taking antidepressants for years, stop taking them knowing he might as well be putting candy in his mouth?
“He knows it works for him…. ‘But I know they work for me, because I feel better when I take them… I get better.'”
This is what psychologists call “confirmatory bias,” believing that something must be true because it aligns with one’s own beliefs about it. But at the end of the 60 Minutes Overtime piece, she backtracks yet again:
“If a sugar pill is just as good, how can we keep prescribing these [antidepressant] pills?” asks Stahl.
I’m left scratching my head, and like Stahl, walking away from this piece really confused.
I suspect antidepressants do work, for the reasons mentioned above about the selectivity of Kirsch’s own research into this issue. He has, however, clearly demonstrated that we may underestimate the power of placebo. There may be ways to harness this power in some way, some day… but it has to be done in an ethical manner — meaning that you can’t just lie to people about their treatment in order to gain similar benefits.
Perhaps it will also inform future FDA drug trials, so they are designed with a better understanding of these effects.
For further reading…
60 Minutes Overtime video: How the powerful placebo effect works
Read Dr. Kramer’s view in the NY Times: In Defense of Antidepressants
Read Dr. Grossi’s take on this criticism: Are antidepressants expensive placebos?