Preventing severe mental illnesses--new prospects and ethical challenges.

We review some exciting recent developments in studies of psychoses in general and schizophrenia in particular that offer hope such illnesses can be identified and treated early. Early treatment promises better outcomes for both the affected individuals and their families, and perhaps even the prospect of true prevention. But testing such interventions in vulnerable patients can raise ethical difficulties that if not adequately addressed may harm patients and hamper the development of these interventions. We believe there are appropriate ways of dealing with the ethical problems in the early intervention field, though we also suggest that additional work on both scientific and ethical fronts will need to be done to make these ways real. As a start toward that end, we have summarized a number of the debates in the field and from the following articles, and have distilled five 'points to consider' that interested parties will need to take into account.