In the doctor-patient relationship the European ethical tradition respects three main principles: 1. the principle of benefit, 2. the principle of justice and 3. the principle of respect of personality. In particular the latter holds a specific position in medical research. The author discusses ethical principles of enlistment of experimental subjects into psychiatric studies, where patients frequently are unable to evaluate themselves the consequences of their decision. The author mentions the rules of obtaining so-called informed consent for participation in psychiatric research. He describes the principles of the work of ethical commissions based on international ethic codes, adopted after the Second World War.