Hence, evidence that a longer duration of untreated psychosis (DUP) aggravates-and early intervention with medication and social supports ameliorates-the long-term adverse consequences of psychotic disorders generated a great deal of interest. 3,4 This knowledge led to the development of diverse early intervention services worldwide aimed at this putative "critical window." It raised the possibility that appropriate interventions could prevent the long-term disability that makes chronic psychosis one of the most debilitating disorders. 5,6 However, even beyond the varied cultural and economic confounds, it is difficult to assess, compare, and optimize program effectiveness. 7 Obstacles include paucity of sufficiently powered, well-designed randomized controlled trials (RCTs), the absence of diagnostic biomarkers or other prognostic indicators to better account for the inherent heterogeneity in the population and associated outcomes, and the absence of modifiable risk factors that can guide interventions and provide intermediate outcomes. 4,[8][9][10] To better appreciate these issues, it is important to distinguish whether a program is designed to prevent psychosis, or to mitigate the effects of psychosis. Two models include the:• Prevention model, which focuses on young individuals who are not yet overtly psychotic but at high risk • First-episode recovery model, which focuses on those who have experienced a first episode of psychosis (FEP) but have not yet developed a chronic disorder.
Early interventions for psychosis