NDARC Technical Report No. 61 (1998)
Recently there have been heightened concerns in Australia about reports of increased heroin use amongst youth, and suggestions that the age at which heroin use is initiated has declined. Despite these concerns, there has been little empirical information examining either the prevalence of heroin use among youth or time trends in age of initiation to heroin use.
This report examines whether there has been a decrease in the age of initiation to heroin use using two data sources: a combination of the Sydney component of the ANAIDUS and the ASHIDU, and the 1995 National Household Survey. Analyses of the ANAIDUS and ASHIDU data, which contained information from 1,292 heroin users, indicated that the age of initiation to heroin use has declined steadily in recent years: amongst individuals born in 1940-1949 the average age of initiation was 20.5 years (CI = 19.3-21.6) while amongst those born in 1970-1979 it was only 16.5 years (CI = 15.1-17.9). Individuals born in the intervening years had average ages of heroin initiation which were between these extremes (18.8 (CI = 17.8-19.9) for those born in 1950-59 and 18.3 (CI = 17.3-19.2) for those born in 1960-69.
These findings were confirmed by analyses of the National Household Survey. While this survey identified only 54 individuals for whom information on age of initiation to heroin use was available, it was possible to detect a significant association (p<.005) between decade of birth and age of initiation to heroin use: the mean age of initiation amongst individuals born during 1970-1979 was 17.7 years (CI = 16.0-19.3); amongst those born in 1960-69 it was 20.8 years (CI = 18.9-22.8) and amongst those born in 1950-59 it was 23.4 years (CI = 20.3-26.5).
Further analysis of the ASHI data indicated that younger age of initiation to heroin use was associated with polydrug use, overdose and crime, after the effects of duration of heroin use had been statistically controlled.
While the two data sets analysed above have different strengths and weaknesses (a small random sample versus a large non-random sample), the convergence of their findings is impressive. Both analyses lead to the conclusion that there has been a decline in the average age of initiation to heroin use in recent decades. These findings suggest that there has been both an increase in the willingness of young people to experiment with heroin and an increased availability of the drug over this time. In combination with evidence that there has been an increase in the amount of heroin being imported into Australia, and an increased demand for treatment for opiate dependence, these data suggest that Australia is experiencing a rapid increase in the use of heroin, particularly amongst youth.