Paradoxical drug response and the placebo effect: a discussion of Grunbaum's definitional scheme

Grunbaum claims that the remedial failure of a treatment's characteristic factors is the generic, objective property of a placebo. He stipulates that a treatment is placebic if this remedial failure exacerbates the target disorder. This stipulation can subsume as placebic effects that might be solely pharmacological, e.g., paradoxical reactions to certain psychiatric drugs. If that exacerbation can be explained pharmacologically, then we might question whether Grunbaum's definitional scheme captures the core identity of what we usually intend by the placebo concept. I propose that this core identity is best captured by a symbolic meaning hypothesis in which psychological factors exert the determinative influence.