Could cannabis, MDMA and mushrooms be the answer the mental illness?

How ‘illicit’ drugs could unlock new mental health treatments

From July, some psychiatrists will be able to prescribe MDMA and psylocibin to patients.


The Therapeutic Goods Administration (TGA) approved MDMA and psilocybin, the active chemicals in ecstasy and psychedelic mushrooms, respectively, to treat depression and PTSD in patients where traditional treatment options have been exhausted.  

This makes Australia one of the first countries to legalise the drugs for medicinal purposes, but some experts are still cautious of its use.  

Dr Katrina Green is a neuroscientist from Molecular Horizons, Faculty of Science, Medicine and Health at the University and Wollongong and has been investigating the effects of drugs like cannabis on the brain for more than a decade. 

She says it is a step forward in mental health treatment, but more research needs to be done. 

“Less is known about how these drugs work, but some clinical trials have shown that these substances can improve depression and symptoms of PTSD for people who are not experiencing relief from current pharmaceuticals,” says Dr Green.  

“This suggests that they possess unique mechanisms of action compared to current anti-depressants and anxiolytics. We have some preliminary hints about what might be happening in the brain, but much more research is needed to fully understand how they work and whether they are they safe.” 

Help or hindrance? 

Substantial research has shown links between the use of illicit substances and increased risk of mental illness, so how can they work as a treatment? 

Dr Green says while the use of MDMA, cannabis and psilocybin have a stigma due to their recreational use, more awareness is emerging about their potential use as medicines for people who are suffering chronic mental illnesses, through testing by clinical experts in a controlled environment.  

“When cannabis or psychedelics are used recreationally, chemicals are added to the brain that push chemical signalling systems out of balance to feel a ‘high’ or euphoric feeling, which can sometimes also create an anxiety or paranoia effect. As with any medication, we only take a medicine when we feel unwell and have an imbalance somewhere in the body,” she says.  

“If we take a medicine when we don’t need it, when we don’t have an imbalance that needs fixing, then it can have a negative effect by creating an imbalance. This is the difference between what is termed as ‘recreational drugs’ compared to utilising prescribed cannabis, psylocibin or MDMA as a medication for an illness. Pharmaceutical grade medications are also safer than the ‘black market’ due to Australia’s strong regulatory frameworks and quality standards.” 

Dr Katrina Green is in a lab, wearing a blue lab gown, seated at a bench leaning against it and smiling.

Dr Katrina Green from the University of Wollongong

The science behind the substance 

Dr Green says there is still much to learn about the brain-altering effects of different recreational substances, such as cannabis. It’s something her research laboratory group is still investigating. 

The lab found that cannabidiol (CBD), one of the major non-intoxicating psychoactive compounds in cannabis, alters the GABA and glutamate - the excitatory and inhibitory neurotransmitters of the brain. 

“GABA and glutamate act as stop-and-go signals and regulate other chemical signals like serotonin, norepinephrine and dopamine,” explains Dr Green.  

“Delta-9 tetrahydrocannabinol (THC), the substance in cannabis that causes the feeling of being ‘high’, also acts on these systems. So loosely speaking, when there is an imbalance in chemical signalling in the brain, for example during PTSD, anxiety or depression, medicinal cannabis may have an ability to restore balance to these signals.” 

She cautions, “Any medication (new or old) can be dangerous and should be prescribed and monitored by appropriate specialist doctors. Some people can have negative reactions to medicines, while other people find that certain medicines help with their illness.” 

While most research focuses on the effects of THC and CBD, Dr Green is broadening her research to investigate some of the hundreds of other compounds found in cannabis, including terpenes and flavonoids, to find new potential benefits for the brain.  

The future of ‘illegal’ drugs in medicine 

While medicinal cannabis is already legal in Australia, under similar regulations to those for MDMA and psilocybin, accessibility to the drug is limited.  

Medicinal cannabis is not currently covered by the Pharmaceutical Benefits Scheme (PBS) and the out-of-pocket cost to patients can be anywhere between $50 to $1000 per week.  

Dr Green says it’s important to look for new solutions while being cautious of potential side effects.  

“Mental illnesses are more prevalent in our society than ever before and new treatment options are needed,” she says.  

"If we can help even one person then this is a big step forward – but with so much unknown about the cannabis and psychedelics world, long-term safety remains an important question.” 

Always consult a qualified medical specialist regarding questions and decisions about medications.