News
Pilot studies demonstrate effectiveness of MDMA for post-traumatic
stress disorder.
Lizzie
Buchen
Ecstasy, a drug that is illegal in most countries, is showing
increasing potential as a treatment for post-traumatic stress
disorder (PTSD), according to clinical-trial results presented at a
conference in San Jose, California, today. The effect seems to
continue for years after the initial treatment.
People can develop PTSD after traumatic experiences such as sexual
abuse, or witnessing extreme acts of violence. Patients are plagued
by flashbacks and nightmares, and often become emotionally numb and
easily frightened. Treatment includes cognitive behavioural therapy
and selective serotonin reuptake inhibitors (SSRIs) such as
paroxetine (Paxil) and sertraline (Zoloft), but many people with
PTSD do not respond to these treatments.
Ecstasy, otherwise known as MDMA
(3,4-Methylenedioxymethamphetamine), causes the release of
neurotransmitters such as serotonin in the brain, and so could help
to decrease the patient's fear and defensiveness during treatment
The drug was used during therapy in the 1970s but with the rise of
rave culture in the 1980s, the US Drug Enforcement Agency and the
World Health Organization listed MDMA as a Schedule I drug — a
classification reserved for drugs with no medical use and high
potential for abuse — making it nearly impossible to use in
clinical trials.
Since
1986, the Multidisciplinary Association for Psychedelic Studies
(MAPS), a nonprofit research group based in Santa Cruz, California,
has struggled to obtain permission to study the therapeutic
potential of MDMA, other psychedelic drugs and marijuana, but now
the group's efforts are beginning to bear fruit. The first two
preliminary human trials, in the United States and in Switzerland,
have had encouraging results, with most of the people with PTSD who
were tested showing lasting improvements.
"The
results were very promising, and there were no safety problems or
serious adverse events, but we need to replicate this," says
Michael Mithoefer, a psychiatrist based in Mount Pleasant, South
Carolina, who led the US study.
The
results were presented on Friday at the Psychedelic Science in the
21st Century conference, hosted by MAPS, which funded both pilot
studies.
The
US study was the first in the United States to look at the
therapeutic effects of MDMA on PTSD, and was completed in late 2008
(see 'Illegal drug shows promise in treating trauma
symptoms'). The 20 patients, mostly women, had been resistant to
psychotherapy and standard PTSD drugs. Therapists administered MDMA
to the patients during two or three 8-hour "experimental sessions",
spread amongst a series of 20 to 30 psychotherapy sessions.
Two
months after the last session ended, only 15% of the patients who
received MDMA still met the criteria for PTSD, whereas 85% of the
placebo group did.
In
long-term follow-up, averaging 3.5 years after the initial
treatment, most of the people remained free of PTSD — of the 16
patients who participated in the follow-up study, 13 still did not
meet the criteria for PTSD. Mithoefer notes, however, that the
people who have not yet elected to participate in the long term
follow-up may have done so because they had not fared well.
"It's
interesting, and sounds promising," says Kathleen Brady, a
psychiatrist at the Medical University of South Carolina. But she
notes that it's difficult to interpret the findings because the
therapists were able to work out which patients received MDMA and
which received placebo. "They could have been biased and treated
the patients differently. That's definitely a concern."
In
the second study, Peter Oehen, a psychiatrist in Biberest,
Switzerland, followed the same protocol with 12 people with
treatment-resistant PTSD. Although some people treated with MDMA
showed an improvement in their symptoms, the results from this
trial were not statistically significant.
"In a
way the results were good enough to get approved as prescription
medicine," says Rick Doblin, MAPS founder, pointing out that the
SSRIs Zoloft and Paxil, which have FDA approval for treatment of
PTSD have even more modest benefits for patients. "But it's true
they were not as good as the US study. We're trying to understand
why. It could very well be cultural variables, or therapist
variables. We know it's not just the drug that does the work."
The
difficulty with replicating the success of the US trial is not very
surprising, says Murray Stein, a psychiatrist at the University of
California, San Diego, who is director of a 10-site clinical
consortium devoted to researching PTSD and traumatic brain
injury.
"PTSD, and all of mental health research, is full of small,
well-done studies that never get replicated," he says. "I'd love to
see a bigger, well-powered study done. But until then, it's just
kind of neat, but something I've seen 20 times before, something
that often doesn't pan out."
MAPS
has initiated a pilot study with US veterans and wants to run
experiments in other countries, both to make sure the drug works in
different cultural contexts, and to make the approval as a
prescription medicine more likely. The group is now working to get
approval for studies of MDMA for PTSD in four other countries:
Canada, Israel, Jordan and Spain. But with these different
governments and cultures come new hurdles.
"Things are much slower than we expected in Canada, where we'd be
the first psychedelic research in 40 years," says Doblin. "And the
biggest stretch is going to be in Jordan. That's a culture where
the psychedelic experience of the 1960s didn't happen, so there's
no reservoir of therapists and psychiatrists that know about these
things from when they were younger."
That
historical difference makes the Jordan study particularly
important, says Doblin. "We want to show that these drugs can be
mainstream," he says. "It's not just for people who have done drugs
before. It's for normal people, for anyone."