[Clinical assessment of the ultra high risk of developing a a psychotic disorder; review and critical reflection].

Background: It may be possible to improve the prognosis of psychotic disorders by the timely recognition and treatment of the early stages of these disorders. Since the first psychotic episode is often preceded by a period of non-specific symptoms and functional decline, it could be worthwhile investigating whether this early phase can be detected.

Aim: To review existing diagnostic approaches and clinical instruments that are currently used for prospective identification of the prodromal phase.