MDMA, or as it's better known, ecstasy, is one of the most heavily regulated drugs worldwide.
But two leading neuroscientists have just published a commentary calling for more research into the substance, claiming that understanding how it works could hold the key to new therapeutic compounds and treatments for psychological conditions.
"We've learned a lot about the nervous system from understanding how drugs work in the brain – both therapeutic and illicit drugs," said Robert Malenka, a psychiatrist and neuroscientist from Stanford University.
"If we start understanding MDMA's molecular targets better, and the biotech and pharmaceutical industries pay attention, it may lead to the development of drugs that maintain the potential therapeutic effects for disorders like autism or PTSD but have less abuse liability."
This isn't the first time that researchers have shown that MDMA could have potential in treating psychiatric disorders - a trial of 12 people with PTSD, or post-traumatic stress disorder, showed that, in conjunction with counselling, the compound could treat the condition without any ill side effects.
Six years later, 11 of them hadn't had any PTSD symptoms return, and none had started abusing drugs (the 12th member of the original study wasn't available for the follow-up).
Another study in 1998 showed that one session of MDMA-assisted psychotherapy was as beneficial as a decade of regular talking therapy.
"MDMA's therapeutic effect was often rapid, happening over the course of hours or only a few short therapeutic sessions," Malenka and co-author Boris Heifets write in Cell.
The benefits appear to come from the fact that MDMA triggers electrochemical messaging in the brain that increases feeling of connection and empathy - which is why scientists class the drug as an "empathogen".
But on a neurological level, researchers still don't really understand how it works - and although initial brain scans have provided insight into which regions of the brain are involved in the process, there's still more to find out.
Which is why the scientists are calling for approval to use "all the available tools of modern basic and clinical neuroscience research to map MDMA’s mechanism of action in the brain".
Right now, MDMA is classed as a schedule I drug in the US, alongside things like LSD and heroin - and that means they're extremely hard for researchers to get ethics approval and funding to study.
To be clear, the researchers openly acknowledge that the drug can be dangerous in large doses, and shouldn't be used recreationally. But "irrational barriers to its study based on poor understanding of its actions need to be minimised so that appropriate clinical studies can be performed," the researchers write.
"You can give it to human beings under appropriately controlled, carefully monitored clinical conditions and do fMRI and functional connectivity studies, and you can begin to build up a knowledge base in an iterative fashion, combining the animal and human studies, where we start to gain more traction in understanding its neural mechanisms," added Malenka.
MDMA isn't the only psychoactive drug that scientists think could be beneficial for human health - in early trials, ketamine has been shown to have an "unbelievable" effect when it comes to treating depression.
And a trial of 12 people has shown that magic mushrooms can also be used alongside psychotherapy to improve long-term depression in less than three weeks.
Researchers in April also completed the first imaging study of the brain on LSD, which lead researcher of the study, David Nutt, said was for human neuroscience "the same as the discovery of the Higgs boson".
If the two Stanford researchers have their way, MDMA will be next to receive this level of research.
"Drugs like MDMA should be the object of rigorous scientific study, and should not necessarily be demonised," concluded Malenka.