Estimating the number of regular and dependent methamphetamine users in Australia, 2002–2014
Almost 270,000 Australians aged between 15 and 54 years are regular users of methamphetamine, and over half of those are dependent on the drug, according to research that comprises the first quantification of the size of this population published in the Medical Journal of Australia.
A research team led by NDARC’s Professor Louisa Degenhardt and Dr Sarah Larney estimated the overall numbers of regular and dependent methamphetamine users in Australia for each year from 2002–03 to 2013–14, and the numbers by age group (15–24, 25–34, 35–44 and 45–54 years).
Indirect prevalence estimates were made for each year from 2002–03 to 2013–14. The study applied multiplier methods to data on treatment episodes for amphetamines (eg, counselling, rehabilitation, detoxification) and amphetamine-related hospitalisations to estimate the numbers of regular (at least monthly) and dependent methamphetamine users for each year. Dependent users comprised a subgroup of those who used the drug regularly, so that estimates of the sizes of these two populations were not additive. The key findings were:
- There has been a consistent rise in the number of regular and dependent users since 2010
- The number of regular users has almost tripled from 90,000 in 2009/2010 to 268,000 in 2013-2014
- These figures provide us with the first quantitative estimate of the scale of the problem of methamphetamine use in Australia
- This increase in use has been most concentrated in users aged 15-24 and users aged 25-34. Dependent use has doubled in both of these groups
- Rates of use were highest in the 25-34 year old age group with 1.5 per cent now believed to be dependent, compared with 0.8 per cent in 2009/2010
- Worryingly 1.14 per cent of young people aged 15-24 are estimated to be dependent on the drug compared with only 0.4 per cent in 2009/2010
- The rise in dependent users among younger age group (15-24) suggests an increase in new methamphetamine users
Implications: there is a need for early intervention among younger people aged 15-24 to prevent transition into dependence, and greater engagement of clients in treatment and other health services.