Competence to give informed consent to clinical studies. Statement by the Taskforce on "Ethical and Legal Questions" of the Association for Neuropsychopharmacology and Pharmacopsychiatry ("Arbeitsgemeinschaft fur Neuropsychopharmakologie und Pharmakopsychiatrie [AGNP]")

Over the last 50 years, patient autonomy has become an increasingly importa nt part of the principles of medical ethics, or rather of the ethics of the doctor-patient relationship. While the principle of charity and the associ ated paternalism became less important, the patient's active consent became more and more relevant (Sass, 1989; Buyer 1998; Nedopil, 1998). This devel opment was inevitably also accompanied by a demand for more detailed inform ation prior to medical interventions (Appelbaum and Grisso, 1988; Weisstub, 1990; Kreussler, 1997; Ulsenheimer, 1995; Laufs, 1997; Sommer, 1997) and f or complete information on medical procedures subsequent to interventions ( e.g. Bender, 1997). Determination of a person's competence to give informed consent is a central problem in the assessment of his expression of consen t to a medical intervention. The capacity to adequately express consent can be impaired at certain stages of life and during some illnesses. Patients in borderline situations, children, mentally ill patients and old people wi th dementia may either be limited in their capacity to give informed consen t, or be completely unable to do so. This results in special ethical proble ms when such groups are included in research projects.