Ih. Jones et al., DECLINE IN DIAGNOSES OF SCHIZOPHRENIA IN TASMANIA DURING THE PERIOD 1965-1990, Acta psychiatrica Scandinavica, 95(1), 1997, pp. 13-18
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.