Psychedelic substances MDMA and psilocybin - more commonly known as ecstasy and magic mushrooms - will soon be used in the treatment of depression and post-traumatic stress, Australia's drugs watchdog has announced.
Psychiatrists will be able to prescribe the two substances from July, the Therapeutic Goods Administration said after finding "sufficient evidence for potential benefits in certain patients".
The two drugs are currently "prohibited substances" and can only be used in closely controlled clinical trials.
The administration said they had been found to be "relatively safe" when administered in a medical setting and provided an "altered state of consciousness" that could help patients.
Mike Musker, a mental health and suicide prevention researcher at the University of South Australia, welcomed the move as "long-awaited".
"There are many people in the community experiencing PTSD (post-traumatic stress disorder) and depression, particularly army veterans and people who have worked in emergency services, where standard psychiatric drugs have not worked and offer no relief," he said.
Mr Musker said the two drugs "reduce inhibitions" and could help people process difficult images and memories.
For now the use of MDMA and psilocybin will be limited to the treatment of depression and post-traumatic stress.
But advocates hope to one day use them for alcohol dependence, obsessive compulsive disorder and eating disorders.
Psychedelics have been used by indigenous peoples for millennia, but Western researchers only started seriously looking into their potential uses in the middle of the last century.
The drugs became symbols of the counter-culture movement of the 1960s and were banned.
Authorities in Canada and the United States are among those who have already permitted the medical use of MDMA and psilocybin.