Methylamphetamine consumption has risen across the country while other substances has dropped, a national wastewater analysis has found.
The Australian Crime Intelligence Commission's (ACIC) National Wastewater Drug Monitoring Program measures the presence of 12 different substances, and provides information about trends in drug consumption.
For its most recent report, the program tested samples collected from 57 treatment plants across the country in April, covering 56 per cent of the population, as well as 20 capital city sites in June.
The report, released on Wednesday, showed methylamphetamine use increased nationally from December 2021 to April 2022, but nine other substances decreased during the same period including MDMA, MDA, oxycodone and fentanyl, which fell to record low levels.
ACIC chief executive officer Michael Phelan said the decreases were "likely related to supply issues".
ACIC said the increase in methylamphetamine consumption across the country to longer term average levels likely reflected normal market forces, now that the illicit drugs market was less impacted by COVID-19 restrictions.
The report stated methylamphetamine consumption had recovered to a different degree in most jurisdictions since a decrease in levels in mid-2020.
It said substantial increases in use have been evident in many parts of the country since the start of the year, most notably in New South Wales, South Australia and Western Australia.
The report showed regional South Australia ranked highest in the country for methylamphetamine consumption under the most recent data and Adelaide had the second highest average capital city consumption, behind Melbourne.
South Australian Network of Drug and Alcohol Services (SANDAS) executive officer Michael White said SA had "always had higher rates" of methamphetamine compared to the eastern states, as it was a cheaper and more easily available alternative to cocaine.
“We tend to see the distribution of drugs here is quite price sensitive," he said.
"Cocaine is too expensive, so people buy methamphetamine.
"And this is one of the things that happens in the drug market — if people can't afford an expensive drug, they’ll use a cheap drug and if a drug becomes harder to get they’ll use something else."
The consumption estimates in the report are expressed as the amount of drug consumed per 1,000 people.
"It doesn't tell you how many people are using those drugs," Mr White said.
Mr Phelan said wastewater analysis was an important measure of the demand for drugs with abuse potential.
“Understanding drug consumption at the population level supports effective allocation of resources and informs appropriate demand, supply and harm reduction strategies," he said.
"This is critical in addressing drug use in Australia."
Mr White said the report showed "some really positive news" about substance issues in South Australia when looked at longitudinally, such as stable levels of heroin and low levels of ketamine, MDMA and MDA.
He said he was most concerned about alcohol use in South Australia, after COVID-19 restrictions and with the introduction of rapid alcohol delivery in the state.
"Alcohol use goes up when people are under stress, when people have more time on their hands, and when alcohol is easier to access," he said.
Mr White said there was a significant need for more drug and alcohol services across the country, as providers were only meeting about 50 per cent of demand.
"I'm concerned about the fact that there have been rises in the amount of alcohol being consumed and there has been some variations in some of the drugs being used, but there's been very limited increase in the amount of funding and what we are seeing is very high rates of demand for treatment," he said.