The role of under-employment and unemployment in recent birth cohort effects in Australian suicide

High suicide rates evident in Australian young adults during an epidemic period in the 1990s appear to have been sustained in older age-groups in the subsequent decade. This period also coincides with changes in employment patterns in Australia. This study investigates age, period, and birth cohort effects in Australian suicide over the 20th century, with particular reference to the period subsequent to the 1990s youth suicide epidemic in young males. Period- and cohort-specific trends in suicide were examined for 1907–2010 based on descriptive analysis of age-specific suicide rates and a series of age–period–cohort (APC) models using Poisson regression. Under-employment rates (those employed part-time seeking additional hours of work) and unemployment rates (those currently seeking employment) for the latter part of this time series (1978–2010) were also examined and compared with period- and cohort-specific trends in suicide. A significant increasing birth cohort effect in male suicide rates was evident in birth cohorts born after 1970–74, after adjusting for the effects age and period. An increasing birth cohort effect was also evident in female suicide rates, but was of a lesser magnitude. Increases in male cohort-specific suicide rates were significantly correlated with increases in cohort-specific under-employment and unemployment rates. Birth cohorts that experienced the peak of the suicide epidemic during the 1990s have continued to have higher suicide rates than cohorts born in earlier epochs. This increase coincides with changes to a labour force characterised by greater ‘flexibility’ and ‘casualised’ employment, especially in younger aged cohorts.