Cohort trends in the age of initiation of drug use in Australia

Aim: To examine birth cohort trends in the prevalence of use and the age of initiation of use of: alcohol, tobacco, cannabis, amphetamines. LSD, and h eroin. Method: Data were taken from the 1998 National Drug Strategy Household Surv ey, a survey of a representative sample of Australians aged 14 years and ov er. Nine five-year cohorts were examined among persons born between 1940 an d 1984. The weighted prevalence of use by ages 15 years, 21 years, and life time use, was estimated, as was the average age of first use among users. T he significance of trends was tested using logistic regression (for lifetim e use, use by 15 and 21 years) and linear regression (for age of first use) . Results: Lifetime prevalence of alcohol and tobacco use was similar among a il birth cohorts. The prevalence of illicit drug use - cannabis, amphetamin es, LSD and heroin - increased with successive birth cohorts and more recen t birth cohorts reported using licit and illicit drugs at a younger age. Conclusions: More recent cohorts are move likely to use illicit drugs at so me point in their lives. Greater numbers of persons from more recent birth cohorts may be at risk of developing substance-related problems.