Doctors in Australia are warning about a “significant increase” of patients developing psychosis after being prescribed medicinal cannabis, according to ABC Australia. 

“We’re seeing a lot of people getting medicinal cannabis who end up with their first psychotic episode, or we’re seeing it dispensed to people who have psychotic conditions, and these people are relapsing,” said Brett Emmerson, Queensland chair of the Royal Australian and New Zealand’s College of Psychiatrists. 

He told ABC his college wants better regulation of medical cannabis products and more scrutiny on prescription practices. 

He continued: “Part of the issue … are these single-issue clinics which, if you ring up, it doesn’t matter what you say you want. They’ll provide it for you even though there is probably no indication that it will work, and the prescribers never contact the person’s treating doctor.”

“You find out two or three months down the track that one of your patients has been on medicinal cannabis — not prescribed by you but by some other prescriber — usually a doctor who hasn’t had the professional courtesy of contacting you and letting you know,” he said. 

Professor Emmerson reports that Queensland’s Metro North Health, Australia’s largest public health service, is experiencing a rise in psychosis cases linked to medicinal cannabis use.

“The Metro North early psychosis service reports 10 per cent of their new presentations — so these are kids aged 16 to 21 — are people who’ve ended up on medicinal cannabis and are becoming psychotic,” he said in his interview. 

“A lot of other mental health services are reporting several admissions a week of people who have been placed on medicinal cannabis who shouldn’t be on it,” he added. 

“Medicinal cannabis is causing harm. The medication is unregulated, and it’s being used widely for a whole range of conditions for which there is no evidence.”

Professor Jennifer Martin from the University of Newcastle highlights that medicinal cannabis is causing a rise in emergency department visits due to psychosis and cannabis hyperemesis syndrome, a condition marked by excessive vomiting from high-potency cannabis.

She notes that many prescriptions are issued online, making it hard for patients to contact their prescribing doctors. Despite its legalization in 2016, concerns persist about its unproven efficacy for anxiety and insomnia.

Regulatory bodies are calling for tighter controls and restrictions on THC-containing products, emphasizing the need for evidence-based treatments and harm minimization strategies.