Patients and physicians correctly identified medication assignments in
70% of the cases in a double-blind trial of an appetite suppressant. The
breach of the double-blind design may have had therapeutic consequences;
correct identification was associated with favorable outcome. These
findings suggest that requirements for describing the side effects of
medications to patients before they give informed consent may help them
guess which medication they receive and thus may influence the integrity of
double-blind studies and the results of controLled trials.