When drug trials are conducted, the gold standard (and requirement for FDA approval) is a double-blind placebo-controlled study. In this kind of drug study participants are randomly assigned to receive either the medication or an inert (does nothing) pill known as a placebo. Neither the doctor not the patient knows whether they are getting the placebo or the real drug.

The study then compares what happens to those who received the real drug versus those who received the placebo and determines the efficacy of the real drug.

The Placebo Effect

This is critical because of something known as the “placebo effect.” The placebo effect is this odd scenario where people get better just because you give them a pill, even if the pill does nothing. Doctors and scientists don’t understand the placebo effect but not only will people get better on a placebo, but they will even experience side effects – something that isn’t possible given that the placebo is inert. But the brain is a powerful thing and something we don’t fully understand.

And one of the problems with antidepressants (and many medications) is that sometimes they aren’t better than the placebo. Additionally, sometimes when they are better than the placebo, it’s only by a small margin. Drug companies have to prove that their drug is statistically significantly better than a placebo in order to get FDA approval but even this statistically significant amount can be very small.

However, this isn’t a piece about how effective are when antidepressants are compared to placebos. This is a piece about how effective antidepressants are compared to no treatment.