>I'm a bit confused by what you mean by "favors" here. Do you mean that an otherwise/previously cannabis-using patient would report more favorable results (and/

>I'm a bit confused by what you mean by "favors" here. Do you mean that an otherwise/previously cannabis-using patient would report more favorable results (and/or fewer negative side effects)? In cases in which the active agent is THC or a similarly psychoactive agent, patients are indeed more likely to report positive overall effects simply because they know they're receiving the active agent; i.e. the placebo effect. This would apply whether they've used cannabis before or not. You don't have this problem with trials of the non-psychoactive cannabis chemicals, which fortunately is most trials.