[Informed consent of patients in psychiatry. Consequences in biomedical research].

After the Huriet law (December 20th 1988) a free, informed and explicit consent procedure has become compulsory in biomedical research. This obligation is particularly uneasy with mental patients. Stricto sensu it excludes from research all psychotic patients unable to become "informed" and to "consent" to something. Moreover age, understanding, the quantity of informations, the personality of investigators and above all patients' suggestibility may be biases when recruiting subjects willing to participate in a trial. It is only after marketing that a thorough knowledge of the scope of a new drug will be established in terms of efficacy. Furthermore, patients informed about the possible ingestion of a placebo may become less responsive to the placebo as well as to the active drug. In a double-blind trial the physician will be unable to explain the effects experienced during the treatment period. The Huriet law should be adjusted taking into account the specificity of the field of psychiatry and being aware of the treatment and investigational problems within the framework of psychiatric emergencies.