OBJECTIVE: To review the literature on early intervention in psychosis and to evaluate relevant studies.

METHOD: Early intervention was defined as intervention in the prodromal phase (primary prevention) and intervention after the onset of psychosis, i.e. shortening of duration of untreated psychosis (DUP) (secondary prevention).

RESULTS: We found few studies aimed at early intervention, but many papers discussing the idea at a more general level. We identified no studies that prove that intervention in the prodromal phase is possible without a high risk for treating false positives. We identified some studies aimed at reducing DUP, but the results are ambiguous and, until now, no follow-up data showing a positive effect on prognosis have been presented.

CONCLUSION: Early intervention in psychosis is a difficult and important challenge for the psychiatric health services. At the time being reduction of DUP seems to be the most promising strategy. Intervention in the prodromal phase is more ethically and conceptually problematic.