The course of schizophrenia: Progressive deterioration, amelioration or both?

Background: Schizophrenia may follow a course of amelioration, deterioration or stability. It is possible that deterioration at the aggregate level may be due to a sub-group of patients with a tendency to deteriorate. Aims: To examine the course of schizophrenia in a national population-based cohort. Methods: All first admissions for schizophrenia in Israel 1978-1986 were followed for readmissions in the Israeli psychiatric hospitalization registry for 10 years (n = 6865). Readmission rates were examined using cluster analysis. This was followed by an examination of changes in readmission patterns. Results: Cluster analysis identified a small cluster of patients who spent more days in the hospital over time and two clusters that improved. A priori classification of the patients into deteriorating, improving and stable (based on days hospitalized per year) revealed that approximately 75% of patients improved over time. Conclusions: Over time a majority of patients appear to improve and a minority appear to deteriorate.