Dark, hidden truth of medical cannabis

There’s been a huge rise in the use of medical cannabis over the past eight years, but are there risks people aren’t talking about?

And half of those patients are at risk of ending up with serious, lifelong conditions like schizophrenia.

In an extraordinary move, a Brisbane public hospital doctor has broken the silence on a disturbing trend showing an upswing in patients presenting with psychosis after recently being prescribed medical cannabis.

Research from Associate Professor Stephen Parker, psychiatrist and clinical lead at the Metro North Hospital and Health Service’s early psychosis service shows one in 10 people referred to his services at the Royal Brisbane and Women’s Hospital and Prince Charles Hospital for support had been prescribed medical cannabis in the three months prior, for issues like anxiety.

The doctor said that the public perception of medical cannabis production as a harmless panacea is understandable due to extensive marketing but the risks are under-recognised.

“Over the last 18 months I have seen more and more young people on a great life trajectory suddenly finding that their lives are falling apart after being prescribed high-dose cannabis,” he said.

The most common cannabinoids found in the cannabis plant are tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is psychoactive, while CBD interacts with the immune and nervous systems.

The Royal Australian and New Zealand College of Psychiatrists Queensland Chair Professor Brett Emmerson is so concerned by emerging surges in psychosis cases he is calling for a ban on products that contain tetrahydrocannabinol (THC), which can lead to psychosis.

And the Australian Medical Association Queensland is demanding that the Therapeutic Goods Administration launches an urgent review into all medical cannabis products.

Professor Emmerson told The Sunday Mail that the problem is statewide and the college has waved the red flag “to every possible medical board”.

“When medical cannabis was first available it was for childhood epilepsy or pain from cancer now it’s regularly used for insomnia or anxiety when there are much better ways to treat these conditions. Now there are a large number of products available that have high levels of THC,” he said.

“I believe that a number of GP prescribers are being investigated by the Health Ombudsman,” Prof Emmerson said.

Medical cannabis dispensaries have become increasingly accessible via brief web consultations or via self-assessment of pre-existing conditions

AMAQ chief Maria Boulton said that members have been worried about the regulatory controls over the medical cannabis market for some time and have raised the issue with the chief health officer.

Medical cannabis was legalised in the state in 2016 and demand has soared. There are over 700 different products on the market with oils, tablets, lozenges and creams.

Dr Boulton said that there’s no evidence that medical cannabis is effective for some of the conditions it is being prescribed for and the effect on patients with some psychotic illnesses can be severe.

“We need the federal and state governments to work together, as the current controls do not appear to be working to prevent harm. We need federal action from the TGA to review these products,” she said.

A TGA spokesperson warned “the majority of medicinal cannabis products supplied in Australia are ‘unapproved’ medicines”.

“It is important to note that the nature of unapproved medicines is that the TGA has not evaluated them for safety, quality or effectiveness,” the spokesperson said.

Dr Laurence Kemp, Medical Lead for medical cannabis clinic Cann I Help said that there is a risk with medical cannabis with high levels of THC but it was the duty of the prescribing doctor to properly assess the correct levels for patients and also assess patients who may be susceptible to psychosis.

“Patient selection for medical cannabis is very important and there must be robust follow up arrangements. Some people do better with the CBD element in the cannabis. It is not something that is the same across the board for everyone,” he said.

The expert said that the black market for medical cannabis was bigger than the medical market and that was a real concern.

“We mostly prescribe for conditions like muscular pain, anxiety and insomnia and people can get some great results,” he said.