Research
Placebos are used in research. Placebo-controlled, double-blind, randomized studies are used to closely examine the therapeutic efficacy of drugs. One part of the subjects receives the drug to be tested (verum), while the control group receives a placebo (identical in appearance, taste and, if necessary, side effects of the verum). A difference between the measured effects in both groups in favour of the verum can thus be regarded as its efficacy. This effect of the verum may be larger or smaller than the placebo effect. The statistical significance of the effect found in scientific studies and in favour of the verum (which in this context must necessarily be distinguished from the relevance of the effect of the verum) is one of the most important prerequisites for the approval of a drug by the competent health authorities.
- Double-blind studies are those in which neither the doctor nor the patients know whether placebo or verum was administered. This eliminates the possibility of influencing the outcome. The double-blind approach can pose challenges to the conduct of studies in which the verum is not in a form that can be easily converted to placebo. Their execution may then be imperfectly realized.
- Randomised means that the control group is determined by chance, for example by drawing lots. This avoids factors such as the stage of the disease being included unconsciously.
Placebotherapy
The placebo effect has a more or less large share in every treatment success. Pure or complementary placebo therapies are also not infrequently used in clinical practice. The administration of placebos for the treatment of complaints is ethically controversial. Especially in pain therapy, placebo effects can strongly support the treatment in a positive way.
How effective placebo effects can be for certain symptoms is shown by a study of patients with irritable bowel syndrome who received three placebo treatments of different intensities. The first group was studied only, the second received sham acupuncture and the last sham acupuncture in combination with empathic, attentive, trusting conversations. In the group with sham acupuncture, the symptomatology improved significantly compared to the untreated group, and in the group with sham acupuncture and additional talks, the improvement in symptomatology was once again significantly greater than in the group treated with sham acupuncture only.
The placebo researcher Bertrand Graz considers the correlation between the positive expectations of the physician and the healing success of a treatment to be so significant that he proposes a new name for this effect factor, curabo effect (curabo: Latin for "I will heal"), instead of placebo (Latin for "I will please").
According to a number of scientists, the placebo effect cannot be equated with spontaneous healing, even though it is suspected that similar biochemical processes can be observed in both. In a spontaneous cure, the body eliminates the disease without any knowing outside help. In the placebo effect, on the other hand, the body is stimulated by external influences that are supposed to have a reinforcing effect on healing. This thesis is opposed by the opposite opinion, according to which the placebo effect is exclusively due to spontaneous remission, natural fluctuation of symptoms and subjective influence of the results on the part of doctors and patients (see below).
Further areas of application
Another area of application in clinical practice is the maintenance of intake habits for an active substance that is administered intermittently (a typical example is the contraceptive pill, where one week per cycle the active substance is suspended).