Not a great article. It omits several relevant known mechanisms. The placebo effect is NOT "all in the mind"; some of it is (and some of the data in the article argues to that), but some of the placebo effect is "in the math" and some is "in the pill" and some of it is "in the measurement".<p>IN THE MATH: For depression in particular, regression toward the mean is huge - people tend to seek treatment when they are <i>unusually depressed</i> and thus tend to feel better at some random later time regardless of whether they get any treatment at all. You can verify this by having two control groups, one of which gets NO treatment rather than a fake treatment. Or assign different groups to start treatment at different times after a variable delay.<p>IN THE PILL: There's really no such thing as an "inactive" pill. The pill is made of <i>something</i>, and that something - even if it's milk sugar - might by chance actually do something useful to the condition you're testing. To rule this out you also need a no-treatment control - simply calling something an "inactive control" doesn't make it one.<p>IN THE MEASUREMENT: If you apply "a treatment" and ask people "is this better now?" the polite ones will say "Yes, I feel a little better" just to be polite, even if they don't. To tease this out you need objective rather than subjective measurements of success.
There's some serious spinning going on in that article.<p>The asthma study showed that (in that particular case) the placebo treatment did not work at all. The patients reported feeling as good as with using the real treatment, but it did nothing to alleviate the actual symptoms.<p>The last paragraph tries to claim that placebo (sham acupuncture) may be as effective as the real treatment (real acupuncture). That's not what the study shows. The result of the study is: the "real acupuncture" doesn't work either.<p>Placebo is the null hypothesis. It's something that all treatments show regardless of their actual effect. It's the level that you have to beat before you can say that your treatment has any benefits.<p>If something is no different than a placebo, that means that it has no effect other than the placebo effect. Therefore, the original treatment does not work. Period.<p>Placebo effect is a psychological hack. You get it regardless of the active component in the treatments. It's about the feelings and expectations of the recipient.<p>In sham medicine, all you get is the placebo effect. But when you get actual treatment, you're benefiting <i>both</i> from the placebo effect and from the treatment itself.<p>I'm not saying that feeling good is not a desired outcome. It's just that if you have real issues that won't be resolved by feeling better, placebo is of no help.