[Schizophrenia and psychosis--prevention and outcome].

Schizophrenia is described as developing through a premorbid phase, a prodromal phase, and a subsequent phase with psychotic symptoms. In the first phase, the only possible intervention is a reduction of the use of cannabis during adolescence. In the prodromal phase, intervention with cognitive behavioural treatment and antipsychotic treatment may postpone or inhibit transition to psychosis. Long duration of untreated psychosis is related to poor outcome. Early detection programmes can reduce the duration of untreated psychosis. There is good evidence that interventions during the early phase of psychotic symptoms are effective in improving several outcomes.