DECLINE IN DIAGNOSES OF SCHIZOPHRENIA IN TASMANIA DURING THE PERIOD 1965-1990

Changes in the rates of diagnosis of schizophrenia in Tasmania, Austra lia during the period 1965-1990 were examined using records from the S tate mental health case register. Analyses were restricted to subjects with diagnoses recorded between the ages of 20 and 29 years in order to reduce possible errors caused by age-standardized methods. There wa s a significant decrease in the rate of non-paranoid subtypes of schiz ophrenia in female subjects, accompanied by a commensurate rise in the rate of bipolar diagnoses in that group. Differential changes in male and female subjects support explanations of phenotypic shifts in pres entation of psychosis as well as changes in diagnostic practice.