This paper will first posit the rationale for intervention before onset, then outline the current usual practice of treating schizophrenia and the determinants ofthat practice. Recent developments that permit or demand a change in this practice will then be elaborated. The article concludes with an elaboration of the currently known risks and benefits of early intervention research. The ethics of early intervention are undergoing a paradigm shift, a shift that supports early intervention research as being necessary to bring empirical balance to territory that is currently overpopulated with zealous opinions.

International declarations that articulate core values, goals and standards have played an important role in enhancing the quality of care in a number of areas of medicine. This document attempts this task for early intervention in psychotic disorders. It was originally inspired by the St Vincents declaration on the care of diabetes and carefully developed by David Shiers and Jo Smith with support from the Initiative to Reduce the Impact of Schizophrenia, National Institute for Mental Health in England and Rethink, resulting in the UK-focused Newcastle Declaration. The World Health Organization and the International Early Psychosis Association then collaborated to produce an international version of the declaration, which articulates the universal principles of early intervention and tries to blend these with local capacities and cultural diversity.

These international clinical practice guidelines were developed with detailed input from 29 invited international consultants, who provided content as well as detailed feedback on draft versions. The final draft of the guidelines was ratified by the Executive of the International Early Psychosis Association and presented and formally endorsed at the Third International Conference on Early Psychosis held in Copenhagen, September 2002. They have been revised slightly to include medications that were not available in 2002, although a fully comprehensive process of update has not yet been conducted. The final version is published in this Supplement with the aim of encouraging further discussion as well as providing practical guidance to clinicians and researchers. A second edition is planned for publication in 2008.