The concept of staging is applied in medicine since many years, in order to better adapt treatment to patients' needs. Some authors have suggested one should also apply this concept to psychiatric disorders. If this approach seems to make sense, concrete progress in the domain are still limited. It is in the field of psychosis that most development have occurred, in the favorable context of early intervention programs. Some very detailed models have recently been proposed where successive stages of psychotic disorders are defined and corresponding treatment options are proposed. However, the limited reliability of clinical diagnoses systems and the absence of biomarkers allowing a more objective delineation of these various stages still hampers the concrete application of such strategies. Despite these limitations, the staging concept has already started to modify the mental health offer, especially for adolescents and young adults, for example through the development of the Headspace centers in Australia and other countries. These centers constitute accessible entry point for help seekers with mental health issues where treatment is defined according to the stage of illness. If such programs seem promising, a better understanding of the mechanisms underlying the development of psychiatric disorders seems important in order to facilitate the identification of stages and define the nature of the treatment needed for each of them, considering such knowledge has been the crucial for the development of the staging model in somatic disorders.