Is the association between psychological distress and risky alcohol consumption shifting over time? An age-period-cohort analysis of the Australian population

This study explored age, period, and cohort effects associated with trends in psychological distress and risky alcohol consumption. Data came from 108,536 Australians aged 14-79 years old from birth cohorts between 1925-2005, endorsing past year alcohol use in the 2004-2019 Australian National Drug Strategy Household Surveys. Risky alcohol consumption was split into exceeding weekly national drinking limits (>10 drinks per week) or daily limits (>4 drinks per day). An extended hierarchical age-period-cohort model was used to investigate differential effects on trends in psychological distress. Psychological distress showed an inverse U-shape throughout the lifespan with a peak in distress at age 60. Exceeding weekly alcohol limits was positively related to psychological distress prior to age 40 while exceeding daily alcohol limits remained positively related across the lifespan. There were relatively flat period effects, with no alcohol-related changes in psychological distress across years. Lastly, psychological distress gradually increased across birth cohorts until a notable spike among Australians born from 1980-2005 alongside weakening alcohol-related cohort effects. Overall, the recent increases in psychological distress did not appear to be meaningfully explained by risky alcohol consumption though risky alcohol consumption remained an important factor to consider alongside psychological distress.