A therapy for post-traumatic stress disorder (PTSD) using the drug MDMA is likely to be approved by US regulators in the next year after the largest clinical trial to date found it was safe and effective in a diverse group of participants.
PTSD is estimated to affect 3.9 per cent of people worldwide at some point in their lives. The only pharmaceutical drugs approved to treat the condition in the US are antidepressants.
“A lot of people with PTSD are depressed and so these drugs target that depression,” says Jennifer Mitchell at the University of California, San Francisco. But this merely lessens the symptoms, rather than dealing with the cause of the condition, she says.
Numerous studies have investigated whether MDMA, also known as ecstasy, could be used in psychotherapy to help people with PTSD. The drug puts people into a more relaxed and trusting state and dampens fearful responses when they recall past trauma, helping them to engage more openly with therapists.
“We know that MDMA facilitates the retrieval and then the reconsolidation of fear memories within the amygdala [part of the brain that regulates emotion],” says Mitchell. “And so somehow in this process of retrieval and reconsolidation, it seems that you are shedding some of the emotionality associated with the memory.”
In June, Australia became the first country in the world to allow doctors to prescribe MDMA for PTSD alongside psychological support.
Mitchell and her colleagues previously showed that MDMA-assisted psychotherapy is effective, in a trial involving 90 people, the majority of whom were white, with severe PTSD.
The latest study involved 104 people in the US and Israel diagnosed with moderate to severe PTSD, of whom 27 per cent identified as Hispanic or Latino and 7 per cent identified as another ethnicity or race other than white. This group is more representative of people with PTSD in the US, so the results can give more confidence that the treatment will work in a wider population, says Mitchell.
In the study, the participants all received three therapy sessions spaced a month apart. Half the group received a dose of MDMA with their therapy sessions, while the other half received a placebo pill.
Following these three therapy sessions, the researchers found that 71.2 per cent of the MDMA group no longer met the diagnostic criteria for PTSD, compared with 47.6 per cent of the placebo group.
In 2017, the US Food and Drug Administration (FDA) gave MDMA-assisted psychotherapy a “breakthrough therapy” designation. This meant that regulators worked with the research sponsors to design the clinical trials so they would deliver the evidence needed for the approval process. As a result, the treatment could receive FDA approval early next year, says Mitchell.
“These are very encouraging results which suggest that this approach may benefit PTSD,” says Allan Young at King’s College London. “Although the benefits and harm should be confirmed in further research, this study brings this new treatment much closer to clinical use.”
“The latest study confirms what the previous ones have shown: that MDMA plus psychotherapy is an effective treatment for PTSD,” says David Nutt at Imperial College London. “Such evidence is why the Australian government has already rescheduled MDMA for PTSD. To save lives and reduce suffering, the UK should rapidly do the same.”
Mitchell says the next question is how long the effects of MDMA-assisted therapy last. “Previous data has shown that they’re very durable and last for years, but we need to replicate that now in a phase III [advanced clinical trial] and see if that’s true, and for whom,” she says.