Review of the operational definition for first-episode psychosiseip

Aim: Given the growing interest in the study of first‐episode psychosis, clinical and research programmes would benefit from a conceptual clarification of how to operationalize ‘first‐episode psychosis’. We review the variety of definitions in use and discuss their relative merits with respect to both clinical (e.g. early treatment) and research (e.g. obtaining meaningfully homogeneous populations) agendas.