There's a lot of interest in the idea that ketamine provides unparalleled rapid, powerful antidepressant effects, even in people who haven't responded to conventional antidepressants.
Earlier this year, I asked:
Ketamine - Magic Antidepressant, or Expensive Illusion?
There have now been several studies finding dramatic antidepressant effects of ketamine, the "club drug" aka "horse-tranquilizer". Great news? If you believe it. But hold your, er, horses... there's a problem.
My concern was that although depressed patients certainly do report feeling better after an injection of ketamine, compared to people given placebo, that doesn't prove that the drug is actually an antidepressant.
Rather, patients might be experiencing an enhanced, 'active' placebo effect, because ketamine causes subjectively powerful hallucinogenic experiences. So the placebo-controlled trials weren't really blinded.
To settle the question, I suggested a three-way trial comparing it both to an inert placebo, and to some other hallucinogen; if ketamine has a specific ...
