RESEARCH INTO THE EARLY COURSE OF SCHIZOPHRENIA HAS IDENTIFIED A PREPSYCHOTIC PRODROMAL STAGE (MEAN DURATION: 4.8 years) and a psychotic prephase (mean duration: 1.3 years). Comparisons of individually matched samples have demonstrated prodromal symptoms common to schizophrenia and moderate to severe depression. It is not until positive symptoms emerge that psychosis and mood disorders become distinguishable from each other. In both disorders the prodromal stage early produces functional impairment and related social consequences. Hence, early intervention is of great public health relevance. This intervention is targeted at manifest symptoms and not at the underlying, still unknown disease process. Cognitive-behavioural therapy at the prepsychotic prodromal stage seems to favourably influence the short-term illness course. In the psychotic prephase, a combination with low-dose antipsychotics seems to have some efficacy. The aim of early recognition by the instruments discussed in this paper is to permit the identification of the largest possible proportion of at-risk persons as early as possible and their referral to appropriate treatment.