How did you account for the placebo effect? Decaf coffee tastes about the same as regular coffee (some people claim to tell the difference, but I can’t except

How did you account for the placebo effect? Decaf coffee tastes about the same as regular coffee (some people claim to tell the difference, but I can’t except that when I get decaf it’s the cheap mass produced stuff and for regular coffee I like to support local roasters). Maybe the taste was triggering the same effects?