I missed that! Good catch. Michael Pollan points out a few of the factors that make studying psychedelics hard in How to Change Your Mind. For macrodoses, ther

I missed that! Good catch. Michael Pollan points out a few of the factors that make studying psychedelics hard in How to Change Your Mind. For macrodoses, there's the obvious problem that you probably know whether you got placebo (he mentions a control drug that gives people "chills" but even that is pretty obviously not LSD) But the bigger issue is that LSD has a huge dynamical set of effects that depend heavily on mindset, expectations, environment, and probably randomness. It's not as straightforward a casual mechanism as say, aspirin. The positive effects of psychs can't be isolated from the supportive environment, the coaching from staff, etc - doing those things wrong can easily negate - or even reverse! - the effect (i.e. bad trips)