It is so named because neither the patient nor the attending physician knows which drug — medicine or placebo — this patient is taking. There is also a simple “single blind” method, when only the patient does not know what he is taking, and an “open” method, when all participants in the treatment or trial know about the drug. There is also a “triple blind method”. It is used in two ways (Shapiro A., 1976, 1978). Some researchers try to isolate, exclude, or minimize the placebo effect by identifying placebo reactors in a group of subjects at the first stage of observation and excluding them from the subsequent study. This approach meets with objections (Shapiro A., 1978): placebo reactors can be diagnosed during the main test with the same frequency as at the preliminary stage. The second option for using the triple-blind method is that, in addition to the patient and the attending physician, the foreman responsible for testing and statistical evaluation of controlled results does not know about the scheme of the study; there is another researcher who has full information about the schedule of the study. It is known from the history of the double-blind method (Shapiro A., 1960) that this procedure was first used in psychological laboratory experiments in 1908 and then in 1912. This technique was introduced into medicine by Gold et al. in 1937. The first publication on the use of double-blind control in psychiatry appeared in 1954. This was a report on the comparison of mefenesine and placebo in patients with neurotic tension (Brody H., 1980). Until 1960, this technique was not generally accepted, and its usefulness was not recognized. Conducting research using the double-blind method requires great thoughtfulness and accuracy to ensure “blindness”. Otherwise, everything “goes down the drain.” It happened that after the first week of the trial, everyone in the ward knew who was taking the drug and who was taking the placebo (Cole J., Gerard R. W., 1959, p. 419). Therefore, there has been a well—founded question in many publications about the double-blind method (Munjak D. J. et al., 1989; Oxtoby A. et al., 1989) – how blind is this method really? Example. A special test of whether patients recognize the drug they are taking in the process of double-blind determination of the effectiveness of a new drug found that 74% of those taking placebo and 43% of those taking phenylpropanolamine (an appetite suppressant for overweight) correctly identified what they were being treated with (Moscucci M. et al., 1987). A placebo was suspected mainly because there were no side effects. That’s why “active placebos” are so necessary — placebos with the addition of substances that mimic local (bitter taste, odor, etc.) and resorptive (lethargy, drowsiness, muscle relaxation, etc.) side effects. Patients with depression who received placebo, imipramine, or phenelzine for 6 weeks under double-blind control correctly identified what they were taking in 78% of cases; 87% of the doctors accurately recognized the drug they were taking (Rabkin J. G. et al., 1986). The double-blind method, provided that the patient knows that one of the drugs he is taking may be a placebo, did not cause an anxious expectation, a rise in blood pressure and a rapid pulse, unlike the “deceptive” use of placebo, when the patient is sure that he is taking a new drug (Kirsch I., Weixel L. J., 1988). The first scientific conference devoted to placebo effects and the double-blind method is considered (K.Rickels, 1986) to be the “Cornell Conference on Therapy”, held at Cornell University in New York in 1946. Of historical interest is the contrast that existed between physicians in the United States and Great Britain, on the one hand, and continental European countries, on the other, in relation to the double-blind method. In the chapter “Some statistical problems of planning and conducting clinical trials” of the fundamental manual “Pharmacological methods of drug evaluation in animals and in the clinic” (ed. Nodine J. H., Siegler P. E., 1964), Mainland D. (1964) cites an episode that took place in October 1961 in West Berlin at an international seminar on medical documentation and statistics. Representatives of the United States and Great Britain gave examples of how doctors and staff, if they are aware of the drug, can unknowingly influence the drug effect in a patient, and insisted on the importance of the double-blind method and the need for its widest possible use. At the same time, representatives of continental Europe considered only the patient’s lack of information about the treatment to be sufficient for control. European doctors trusted their objectivity, and this attitude was, according to the author, typical for most countries at that time. Example. I can confirm that this situation was observed in the early 60s in the USSR. Scientific communication with psychiatrists and doctors of other specialties testified that the double-blind method, like the use of placebo, was rejected for the “reason” that “it is superfluous for us, since we evaluate the effect of the drug based on in-depth clinical observation.” Even the simple blind method was rejected (when only the patient does not know which drug he is taking). All these techniques were called “Western tricks”, techniques of “mechanical surface statistics”. Some of the Russian psychopharmacologists who tried to pay attention to modern methods of drug control received harsh criticism for “pushing Western pseudoscientific trends.” Admittedly, among Russian doctors, distrust of placebos and the double-blind method persists, albeit to a lesser extent, to the present day. It is also supported by additional difficulties associated with obtaining a high-quality branded placebo, staff training, and time and labor spent on statistical processing of the results. However, since 1970, the double-blind method has received almost unanimous recognition. Source: Lapin I. P. “Placebo and therapy” Photo: kapionews.kapiolani.hawaii.edu