Prevention of severe mental disorders, and especially the indicated prevention, has become a main topic in psychiatric research and, consequently, a matter of ethical debates. Neuropsychiatric disorders, however, form a most heterogeneous group of disorders that, among others, strike first in different age groups, differ in outcome and in availability as well as safety of treatments, have more or less understood different aetiologies and are subject to different degrees of stigmatisation and discrimination. And, although the main focus and critic are on the accuracy of prediction and the safety of treatment, concerns and arguments vary with the different characteristics of the considered disorder.

Taking endogenous psychoses as an example, costs and benefits of an early detection, of an early intervention and of prevention research in the prodromal or premorbid phase will be reviewed. It will be argued that the best way to adhere to the major ethical principles in medicine - autonomy, nonmaleficence, beneficence and fairness - in research and clinical practice will have to be reassessed continuously against the background of the current state of knowledge as well as the public opinion. Thereby, great care has to be given to ensuring that the great expected ‘common good’ will not overcome an individual patient's right to his or her own good and that, especially in patients more vulnerable to misuse, i.e., minors and those already impaired in their decision-making capacity, autonomy is given priority.