explanation Three studies will be presented. First, a survey was carried out among 3800 seven- and eight-year-old school children in the province of Groningen regarding hearing voices (auditive vocal hallucinations). Those who heard voices were followed up after five years together with a control group matched on gender and age: is hearing voices among these children persistent or not and how serious is it? Second, a systematic review and analysis of more than 3000 individual patient data was used in a study on the relationship between the duration of untreated psychosis and negative symptoms: how strong are they correlated with each other. The third study focused on the medium term course (about eight years) of schizophrenia. It is a sequel of the medication strategies in first onset schizophrenia (mesifos) trial on feasibility and cost-effectiveness of targeted treatment with antipsychotic among first episode patients: are patients who stopped their medication better off in the end?
aim Incidence and prevalence of early psychotic symptoms should be better acknowledged, together with the influence of factors like negative symptoms, duration of untreated psychosis and (non)use of antipsychotic medication on course and prognosis of psychotic disorders.