From the range of licit (e.g., alcohol and tobacco) and illicit drugs currently in use in Australia, amphetamines are identified as one family of illicit drugs requiring specific and immediate attention. Amphetamines and amphetamine-type stimulants (methamphetamine and ecstasy) are the second most widely used drugs after cannabis and are consumed by 0.3% to 1.3% of the world’s population aged 15-64 (about 14 to 57 million people) (United Nations, 2011).


Lifetime use (ever used) of amphetamines in Australia is estimated at 7.0%, with the age group most likely to have ever used meth/amphetamine being 30-39 year olds (14.7%) (Australian Institute of Health and Welfare, 2011). In 2010, approximately 400,000 (2.1%) Australians (aged 14 or older) reported having used amphetamines in the last year (Australian Institute of Health and Welfare, 2011). The age group most likely to have used amphetamines in the previous 12 months was the 20-29-year-olds, of whom 5.9% were recent users (Australian Institute of Health and Welfare, 2011).


The lifetime use of ecstasy in Australia is estimated at 10.3% (approximately 1.9 million people), with lifetime use highest among those aged 20-29 years (24.2%) (Australian Institute of Health and Welfare, 2011). Almost 550,000 Australians (approximately 3%) reported having used ecstasy in the last year, with recent ecstasy use highest among the 20-29 year age group (9.9%) (Australian Institute of Health and Welfare, 2011).


Cocaine use in Australia has increased from 1.6% of the Australian population (aged 14 or older) reporting cocaine use in the last 12 months in 2007 to 2.1% in 2010 (approximately 390,000 people) (Australian Institute of Health and Welfare, 2011). Recent cocaine use was highest among the 20-29 years age group (6.5%) (Australian Institute of Health and Welfare, 2011). Lifetime use of cocaine in Australia is estimated at 7.3%, with lifetime use highest among the 30-39 years age group (14.4%) (Australian Institute of Health and Welfare, 2011).


Early adulthood is the peak time of amphetamine-type stimulant use. Among amphetamine specific samples, the average age of first amphetamine use is about 18 years. Regular amphetamine use commences at an average age between 19 and 21 years, with females shown to move to regular use earlier than males. In Australian, the mean age for the initiation of ecstasy use is 22.6 years (Australian Institute of Health and Welfare, 2011).


Recent research generally supports the notion that for most drug users (including amphetamine-type stimulant users) poly-drug use, using a combination of licit and illicit drugs, is the norm. Alcohol, cannabis, and tobacco are the most common drugs used in conjunction with amphetamine-type stimulants. Poly-drug use among amphetamine-type stimulant users, particularly concurrent alcohol use, may be of concern as research has suggested that it may result in greater physical and social harms than the separate use of either drug (Breen et al., 2006; Kinner et al., 2012).


While amphetamine-type stimulants are the second most widely used drugs after cannabis in Australia, there is limited information of community patterns of amphetamine-type stimulant use. In Australia, longitudinal studies of amphetamine and ecstasy use and in particular longitudinal studies that recruit amphetamine users away from institutional settings (e.g., treatment services, needle and syringe programs (NSP), watch houses, prisons, and courts) are almost non-existent. Instead, the only other current longitudinal study of amphetamine users in Australia is examining the treatment outcomes of dependent amphetamine users (Methamphetamine Treatment Evaluation Study). The majority of Australian studies of amphetamine use have therefore used a cross-sectional design and institutional samples to examine amphetamine use in young people. These studies have investigated intervention and treatment outcomes, and the relationships between health and crime and amphetamine use. A small number of Australian studies have also attempted to use a community sample to explore amphetamine and ecstasy use in young people; however, none have extended their research longitudinally.


This Natural History longitudinal study of a community sample of users of amphetamine-type stimulants will therefore substantially increase our knowledge of drug use in young Australians. The findings will inform policies aimed at preventing and addressing some of the harmful and costly consequences of amphetamine-type stimulant use for individuals, their families, and the wider community.

 

References
2010 National Drug Strategy Household Survey Report. Cat no. PHE 145 (2011) Australian Institute of Health and Welfare, Canberra.
Amphetamines and Ecstasy 2011: Global ATS Assessment (2011), United Nations Office on Drugs and Crime.
Brecht M-L, O’Brien A, von Mayrhauser C, Anglin MD. ‘Methamphetamine users and gender differences’. Addictive Behaviours 2004; 29(1): 89-106
Breen C, Degenhardt L, Kinner S, Bruno R, Jenkinson R, Matthews, AJ, Newman J. ‘Alcohol use and risk taking among regular ecstasy users’. Substance Use and Misuse 2006; 41(8): 1095-1109
Darke S, Hall W. ‘Levels and correlates of polydrug use among heroin users and regular amphetamine users’. Drug and Alcohol Dependence 1995; 39(3): 231-235
Kinner SA, George J, Johnston J, Dunn M, Degenhardt L. ‘Pills and pints: Risky drinking and alcohol-related harms among regular ecstasy users in Australia’. Drug and Alcohol Review 2012; 31(3): 273-280