Greens leader Richard Di Natale wants to reopen the conversation about decriminalising drugs such as cannabis.
The Australian Medical Association has distanced itself from a new relaxed drugs approach being pushed by the Greens, saying it underestimates the harm illicit drugs do to the community.
Association president Michael Gannon told Fairfax Media he welcomed any initiative that shifted the public conversation about illicit drugs towards rehabilitation and treatment instead of policing and the justice system.
But he said he was "wary" of any push towards decriminalising illicit drugs, including cannabis.
"We should not underestimate the harm that illicit drugs do everyday in our community," Dr Gannon said on Sunday.
The party abandoned its blanket opposition to the legalisation of illicit drugs in its policy platform after members voted to support changes driven by leader Richard Di Natale at their national conference in Perth on Saturday.
Senator Di Natale told the conference the global "war on drugs" had failed and it was time for a dramatically different approach.
"I think it's about time Australia had this conversation because it's killing our kids," he said.
The Greens want a new independent national regulatory authority to assess and reduce the harm of illicit drugs - an approach that would likely lead to the decriminalisation or legalisation of drugs like cannabis.
The body would assess drugs on a case-by-case basis, but Senator Di Natale stressed harder drugs like ice and heroin would not be legalised under this model.
Health Minister Sussan Ley swiftly rejected the Greens' calls for change.
"The Coalition government is against all forms of illegal drugs, and is particularly concerned about the impact ice is having across Australia, especially in regional areas," a spokesman for the minister said.
The president of the Australian Medical Association, Michael Gannon, says the existing legislation for illicit drugs is right.
There's an undeniable association between cannabis and mental illness
"The Australian government will never legalise a drug that destroys brain function, mental wellbeing, general health, employment, relationships, lives and families."
The most recent statistics from the Alcohol and Drug Foundation show 15 per cent of Australians used an illicit drug in the past twelve months and 42 per cent had used illicit drugs at some point in their lives.
Cannabis was the most commonly used drug by people aged 14 and over.
The research showed the proportion of people using methamphetamines - including ice - had not changed.
But among the people who used these drugs there was a change in their drug of choice, with the use of speed decreasing and the use of ice doubling between 2010 and 2013.
Among the people who used ice, the proportion of those who used at least once a week or more also increased.
The research found that although cannabis was the drug most likely to be taken by people who used illicit drugs, it was methamphetamines people named as the drug of most concern to the community.
Dr Gannon said the case for medicalised cannabis had shown doctors "aren't afraid of science and making informed decisions".
But he warned there were some people who had pushed for medical cannabis "who would like to have a smoke legally".
"There's an undeniable association between cannabis and mental illness," Dr Gannon said.