Almost 270000 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 online by the Medical Journal of Australia.

Researchers led by Professor Louisa Degenhardt, from the National Drug and Alcohol Research Centre at the University of New South Wales, 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).

They found that in 2013-14 there were 268 000 regular methamphetamine users and 160 000 dependent users aged 15-54 years in Australia.

"This equates to population rates of 2.09% for regular and 1.24% for dependent use," Professor Degenhardt and colleagues wrote.

"The rate of dependent use had increased since 2009-10 (when the rate was estimated to be 0.74%), and was higher than the previous peak (1.22% in 2006-07).

"The highest rates of use were consistently among those aged 25-34 years. In 2012-13, the estimated rate of methamphetamine dependence in this age group was 1.50%.

"It is also important to note the recent increase in estimated dependent use among those aged 15-24 years: in 2012-13, the rate was estimated to be 1.14%."

The authors concluded that: "The increased number of problem methamphetamine users indicates a need to expand services to redress the health problems associated with regular methamphetamine use."