Cohort trends in youth suicide in Australia 1964-1997

Objective: This paper examines trends in the rate of suicide among young Au stralians aged 15-24 years from 1964 to 1997 and presents an age-period-coh ort analysis of these trends. Method: Study design consisted of an age-period-cohort analysis of suicide mortality in Australian youth aged between 15 and 24 for the years 1964-199 7 inclusive. Data sources were Australian Bureau of Statistics data on: num bers of deaths due to suicide by gender and age at death; and population at risk in each of eight birth cohorts (1940-1944, 1945-1949, 1950-1954, 1955 -1959, 1960-1964, 1965-1969, 1970-1974, and 1975-1979). Main outcome measur es were population rates of deaths among males and females in each birth co hort attributed to suicide in each year 1964-1997. Results: The rate of suicide deaths among Australian males aged 15-24 years increased from 8.7 per 100 000 in 1964 to 30.9 per 100 000 in 1997, with t he rate among females changing little over the period, from 5.2 per 100 000 in 1964 to 7.1 per 100 000 in 1997. While the rate of deaths attributed to suicide increased over the birth cohorts, analyses revealed that these inc reases were largely due to period effects, with suicide twice as likely amo ng those aged 15-24 years in 1985-1997 than between 1964 and 1969. Conclusions: The rate of youth suicide in Australia has increased since 196 4, particularly among males. This increase can largely be attributed to per iod effects rather than to a cohort effect and has been paralleled by an in creased rate of youth suicides internationally and by an increase in other psychosocial problems including psychiatric illness, criminal offending and substance use disorders.