It shows cannabis continues to be Australia's most consumed illicit drug but methamphetamine, cocaine and nicotine use are at near-record highs.
The data covers roughly 55 per cent of the population, or about 14.1 million Australians, with wastewater samples taken from 56 sites across the country in December 2023 and February 2024.
Australia ranked fourth out of 34 participating nations in Europe, Asia, America and Oceania from March to May 2023 for illicit stimulant use.
It also had the second-highest methamphetamine consumption per capita compared with 29 participating countries over the reported period.
Australians' love of cannabis was also confirmed, with the nation ranking third of 20 countries for consumption of the drug.
Australia was ranked 20th of 32 countries for consumption of cocaine and 15th of 33 nations for consumption of MDMA.
"These results confirm the considerable per capita consumption of illicit stimulants in Australia, even in world terms, and that our illicit stimulant consumption is dominated by methylamphetamine," the report said.
Queensland, South Australia and Western Australia had the highest rates of meth use at well above average with the consumption of cocaine higher in capital cities compared to regional areas.
A site in Sydney had the highest mean cocaine consumption.
December 2023 saw record high cocaine consumption in capital cities and regional areas, record methamphetamine consumption in capital cities and record nicotine consumption in regional areas.
The average consumption of methamphetamine, cocaine, MDMA, MDMA, ketamine, alcohol and tobacco increased in both capital city and regional sites, despite large seizures of some of the illicit drugs.
August to December 2023 saw declines in capital city oxycodone and cannabis use but increases in everything from alcohol at one end of the spectrum to heroin at the other.
Cannabis is the most consumed drug by a large margin, despite substantial fluctuations.
In December 2023, cannabis consumption was 3.6 times higher than the consumption of methamphetamine and 18.6 times higher than the consumption of cocaine
Overall, cannabis use in Australia has fallen, but it still continues to be the most used substance, the report found.
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