Ecstasy agonistes
A Retracted Study On A Controversial Substance
Raises Questions About The Reliability Of Government-Sponsored Research On
Drugs
Until recently, Ecstasy had been very good to
George A. Ricaurte. An associate professor of neurology at the Johns Hopkins
University, Dr. Ricaurte is the nation's most prominent researcher on
methylenedioxymethamphetamine, or MDMA, the chemical name for Ecstasy, a drug
that produces feelings of intense euphoria, heightened sociability, and
enhanced sensations like touch. His research in the mid-1980s was the first to
suggest that the drug might be damaging to the serotonin system, which is
important in regulating mood, sleep, appetite, and other functions. He has also
received nearly $10-million in federal funds in the last seven years, and some
of his research results have become key building blocks in the government's
much-ballyhooed "war on drugs."
In an
article published in the September 27, 2002, issue of the journal Science, Dr.
Ricaurte (pronounced ri-CAR-tay) launched another salvo in support of that war.
His article warned of new dangers attached to the use of Ecstasy, including the
risk of severe brain damage and debilitating neurological diseases, such as Parkinson's
-- even from just one night of using the drug. It was sensational and
frightening news. Within days, Dr. Ricaurte's findings were printed in scores
of newspapers around the world and repeated on television.
But that particular alarm about
Ecstasy turned out to be false.
A serious
and almost unbelievable mistake -- the primates in the study were injected not
with Ecstasy, but with methamphetamine -- negated both the study and its
startling results.
Almost
exactly a year later, Dr. Ricaurte retracted the article.
That is the
way science works.
A scientist
makes a mistake, discovers it, and issues a retraction. End of story.
But this
was not just any article, and Dr. Ricaurte is not just any researcher. His
previous work had already attracted plenty of critics. Many of them are leading
researchers themselves, who contend that Dr. Ricaurte's studies have been
flawed and biased.
Specifically,
some accuse him of overstating the dangers of Ecstasy to please his government
backers.
The fallout
from the mistake has brought not only Dr. Ricaurte's reputation into question,
but also that of the National Institute on Drug Abuse, which has supported his
research for years. "It kind of gives science a black eye because people
start to question whether NIDA has an agenda," says Glen R. Hanson, a
professor of pharmacology and toxicology at the University of Utah and a former
director of NIDA.
The
retraction has prompted some, like Charles S. Grob, a professor of psychiatry
and pediatrics at the University of California at Los Angeles School of
Medicine and a longtime critic of Dr. Ricaurte's work, to urge a second look.
"The whole thing about Ricaurte really demands a thorough, objective
re-evaluation of the whole record of MDMA research going back 15 years,"
he says.
At the
least, say some researchers, future Ecstasy studies may be ignored or viewed
more skeptically by the public. "An Ecstasy user is not going to believe
any statement by a scientist," says Stephen J. Kish, head of the
human-neurochemical-pathology laboratory at Canada's Center for Addiction and
Mental Health. "Whether they did before, I'm not certain, but it's now
going to be much more difficult."
Holes in the Research
It is not
surprising that Dr. Ricaurte's 2002 claims inspired such a strong reaction.
The drug,
first synthesized by the German pharmaceutical company Merck in 1912, has been
used by millions of people for more than 20 years, and inspired a popular music
and fashion subculture. Many former and current users wondered if the damage
had already been done. But the 2002 study was not the first time that his work
had landed in the public spotlight.
Another
article by Dr. Ricaurte, published in 1998, became the centerpiece of a
provocative anti-Ecstasy campaign paid for by NIDA. In the study, Dr. Ricaurte
scanned the brains of Ecstasy users and compared them with nonusers' brain
scans.
In the
advertising campaign, two of those images were combined into a single image
that the drug-abuse agency used on its Web site and printed on posters and
postcards.
The left
half of the image is labeled "plain brain" and appears healthy and
vibrant.
The image
on the right, which is labeled "brain after Ecstasy" is much darker.
An entire chunk of the organ is missing, as if the drug had eaten away part of
the gray matter.
The
compelling campaign seemed to prove that Ecstasy could cause severe, long-term
brain damage. But was its message -- based on Dr. Ricaurte's research --
accurate?
A German
study published last year using similar methods arrived at a very different
result.
As in Dr.
Ricaurte's study, a radioactive marker was used to tag serotonin neurons in the
brains of human subjects, using Positron Emission Tomography, or PET, scans.
Recent
users of Ecstasy and nonusers were scanned.
Instead of
finding massive reductions in the number of serotonin neurons, as Dr. Ricaurte
reported, the loss was small -- about 4 to 5 percent.
And when
the German researchers looked at those who had not used the drug recently, they
found no decrease at all. There were no holes.
"I've
been on record saying [Dr. Ricaurte's study] was terribly flawed and should not
have been published," says Mr. Kish, who is also a professor of psychiatry
and pharmacology at the University of Toronto. In November Mr. Kish published
an article that highlights the contradictory results of the two studies.
In it, he
also argues that there is little evidence that Ecstasy leads to Parkinson's
disease.
Others,
like Marc Laruelle, an associate professor of psychiatry and radiology at
Columbia University and a specialist in PET scans, agree that Dr. Ricaurte's
study was inaccurate.
In December
The New York Times reported that two of Dr. Ricaurte's former subjects said
they had been encouraged by a research assistant to lie about their past drug
use and that they were mistreated during experiments. Dr. Ricaurte has defended
his methods and called the use of heroin by a subject days before being tested
"unfortunate." He stands by his 1998 article and says that
improvements in technology account for the large discrepancy between the two
studies.
But even
Dr. Ricaurte has doubts about the "brain after Ecstasy" image used by
NIDA. He says he mentioned once to an official at the drug-abuse institute that
the image was of "poor quality" but didn't pursue the matter.
Asked why
he didn't insist that it be corrected, Dr. Ricaurte at first says it was not
his concern.
When
pressed, he concedes, "Maybe I should have picked up the phone and
complained."
The image,
once featured prominently on NIDA's Web site, has been removed.
Monkeys and Mistakes
The risks
that Dr. Ricaurte examined in his retracted 2002 article in Science were
different from those he had explored before.
While the
bulk of previous research had focused on serotonin, this new study examined
MDMA's effect on dopamine, a neurotransmitter linked to emotion and movement,
among other functions.
For years,
studies had suggested that MDMA affected only serotonin neurons.
Many
researchers felt sure that it did not damage dopamine neurons. Dr. Ricaurte
decided to test that notion.
In his
retracted article, he describes how five squirrel monkeys were given three
doses -- with three hours between each dose -- of what turned out to be
methamphetamine.
One of the
monkeys had trouble walking after the second dose, so researchers did not
administer a third. Another monkey died within hours of receiving the third
dose, a victim of hyperthermia, or overheating.
Brain scans
of the three monkeys that had tolerated the drug without apparent difficulty
showed massive reductions in dopamine neurons.
Dr.
Ricaurte later performed the same experiment on five baboons, again apparently
mistakenly administering methamphetamine instead of MDMA. As in the first
experiment, one of the primates died and the others suffered severe damage to
their dopamine systems.
The project
took about two years, according to Dr. Ricaurte. He argues that researchers who
say he rushed his results into publication before thoroughly testing them are
"uninformed." In an e-mail message, Dr. Ricaurte wrote, "We
reject the notion that, due to our experience and knowledge of the literature,
we should have concluded that there was some sort of error."
Such
explanations have done little to satisfy critics.
Dr. Hanson,
who was interim director of NIDA at the time of the study, was suspicious of
the results from the beginning. "I had a chance to talk to him, and I
said, 'George, we never see this. Where is this coming from?'" Dr. Hanson
says. "And he said, 'Well, the dosing paradigm is different and there are
some subtle differences and maybe there is just this little window that you
don't see unless you do it exactly right.'"
Dr. Hanson
was not persuaded. "I just said I really need to see this in more
animals," he says. "And you always like to see it done in another lab."
Because of
Dr. Hanson's doubts, the drug-abuse institute, which had given Dr. Ricaurte
$1.3-million to carry out the research, did not publicize his results.
There was
no press release, no mention on its Web site. Dr. Hanson says that while some
have used the study to accuse NIDA of bias, "the irony is we totally
stepped back from it because we wanted to see it replicated somewhere
else."
One of the
red flags for Dr. Hanson and others was the deaths from hyperthermia of two of
the 10 primates cited in the article.
Deaths from
hyperthermia do occur among Ecstasy users, but they are extremely rare. The
drug can affect the body's ability to regulate temperature, and there is a risk
of hyperthermia, albeit a small one, in people who are exercising vigorously or
who are dehydrated. A recent British study of Ecstasy-related deaths in that
country showed that most of those who died while on Ecstasy were taking it with
another drug.
Dr.
Ricaurte scoffs at the suggestion that the deaths of the two primates should
have alerted him to a problem.
He says
that Ecstasy is known to cause hyperthermia and that because the sample size
was small, the high mortality rate was not significant. Dr. Ricaurte also
points out that the paper made it through the peer-review process at Science.
If the flaws were so obvious, he contends, "Science wouldn't have
published the paper."
Donald
Kennedy, editor in chief of Science and a former president of Stanford
University, says that the publication of the flawed article does not mean that
there was a breakdown in the peer-review process.
How, he
argues, could peer reviewers have known about the drug mix-up? "Sometimes
in science, mistakes get made and you discover ... a paper that on balance,
with perfect hindsight, you wish you hadn't published," he says.
Alan I.
Leshner, chief executive officer of the American Association for the
Advancement of Science, which publishes Science, agrees with Mr. Kennedy's
assessment. Mr. Leshner is a former director of NIDA, and some have speculated
that he had a hand in getting Dr. Ricaurte's paper published -- a charge Mr.
Leshner denies.
He says he
was not even aware of the paper before it was published. He calls the
retraction "unfortunate" but doesn't believe it should end Dr.
Ricaurte's career. "I don't think he should be tarnished for a mistake
that he very rapidly retracted," says Mr. Leshner.
Researchers
like Mr. Kish, however, are less willing to let Science or Dr. Ricaurte off the
hook. "How could Science accept an article purporting to show that Ecstasy
causes dopamine neuron damage in monkeys without having mentioned in the
article that two human studies have been conducted in which there was no
evidence that Ecstasy caused the same type of brain damage?" he says.
Dr.
Ricaurte says he was aware of the studies showing no effect on dopamine and
noted in the article that in previous research Ecstasy had been shown to affect
only serotonin neurons.
He says it
was not necessary to cite the other research because the dosing regime -- the
frequency with which the primates were injected with Ecstasy -- had not been
attempted in this way before, under these conditions. It was possible, Dr.
Ricaurte says, that this dosing regime could account for the unusual results.
And yet,
long before he acknowledged there had been a mistake, others in the field
voiced skepticism. In fact, four months before the retraction, Rick Doblin,
president of the Multidisciplinary Association for Psychedelic Studies, which
supports research on the benefits of drugs like Ecstasy and marijuana, had a
letter published in Science questioning Dr. Ricaurte's results. Dr. Ricaurte
responded in the same issue, dismissing Mr. Doblin's concerns.
When that
letter was published, Dr. Ricaurte says, he was trying to determine why he had
been unable to replicate the results of his earlier experiments. The following
month, he wrote to his backers at NIDA, telling them that the primates had been
injected with methamphetamine, not MDMA. He blamed the error on
"mislabeled drug bottles" from the supplier of the drug, RTI
International. In the report to NIDA, he wrote that tests showed that bottles
from the company labeled MDMA had contained methamphetamine, and vice versa. (A
spokesman for RTI denies that the company mixed up the drugs, but offers no
additional details.)
Dr. Grob,
who has battled Dr. Ricaurte in public for years, has trouble believing that
explanation. "How the hell could he have mixed up drugs?" says Dr.
Grob. "It's unheard of. Where's the precedent for people doing this level
research, of this supposed caliber, where they are mixing up drugs?" He
goes on to call the retraction "one of the more bizarre episodes in the
history of science."
The Straight Dope
So what do
we know for sure about Ecstasy?
After it
was created -- apparently by accident -- in 1912, MDMA mostly disappeared from
view for the next 65 years.
It
re-emerged in the 1970s when psychotherapists found that it helped patients
relax and be more open.
In the
early 1980s, MDMA moved out of the therapist's office and into the streets,
acquiring the sexier name of Ecstasy. It became available for sale legally in
some bars. At one point, tablets could even be ordered by telephone from a
company in Texas.
That all
changed in 1985 when Ecstasy was made illegal even for psychotherapy. That
decision remains controversial, and Ecstasy advocates argue that it was banned
before there was any evidence that the drug was dangerous.
Indeed, the
first studies definitively linking MDMA to the damage of serotonin neurons came
only after the drug was declared illegal.
One of
those pioneering studies was the work of a young researcher named George
Ricaurte.
In those
early years, Dr. Ricaurte had a close working relationship with Mr. Doblin, a
believer in the therapeutic uses of Ecstasy who nevertheless helped arrange
financing and volunteers for Dr. Ricaurte's research. "I felt that those
of us who were looking into the benefits should also be at the forefront of
looking into the risks," says Mr. Doblin.
That
working relationship broke down eventually as, in Mr. Doblin's view, his
colleague began reporting his results selectively -- trumpeting Ecstasy's
harmful effects, and leaving out contradictory data.
That
Ecstasy can damage serotonin neurons in animals is beyond question.
What is
debatable is at what dose that damage occurs, whether the damage is permanent,
and if the damage occurs in humans.
There is
evidence suggesting that, at low enough doses, Ecstasy does not cause damage to
the brain, according to Mr. Doblin. He says Dr. Ricaurte has consistently
ignored and suppressed evidence of this "no-effect level."
That isn't
so, according to Dr. Ricaurte. He says a study in squirrel monkeys did produce
such results, but that there were good reasons not to publish them. "I
discussed these data with Rick Doblin on numerous occasions and explained that
until these negative data were fleshed out by conducting full dose-ranging
studies, they would never be accepted by a peer-reviewed journal," he
wrote in an e-mail message.
Besides,
Dr. Ricaurte argues, the doses were much lower than what people normally take.
"I think it's fair to say that if there is a margin of safety, it appears
to be a narrow one," he says. As for the potential therapeutic benefits of
the drug, Dr. Ricaurte says they are not his concern. "I'm a
neurologist," he says. "What I can speak to are the risks.
Period."
Collateral Damage
The effect
of the retraction on Dr. Ricaurte's career is still unclear.
A spokesman
for Johns Hopkins says the university has taken no action against him because
it was determined that the drug mix-up was not his fault.
He
continues to receive grants from NIDA, but some researchers, including Dr.
Grob, doubt that his professional reputation can ever recover.
"I
don't think he shot himself in the foot. I think he shot his whole foot
off," says Dr. Grob. Dr. Ricaurte argues that the retraction should
bolster his credibility. "Anybody who looks at this current situation
would see that here is a scientist who recognized an error and immediately did
everything in his power to correct the scientific record as quickly as
possible," he says. Dr. Ricaurte continues to research the possibility
that MDMA harms the dopamine system.
Larger
questions about the future of Ecstasy research -- and its public reception --
remain open. Martha Rosenbaum, who has also received NIDA grants to study
Ecstasy, says Dr. Ricaurte's studies have contributed to a steady stream of
misinformation about the drug that has led to fear-driven legislation. For
instance, a bill recently passed by Congress allows the government to prosecute
the owners of establishments where drugs like Ecstasy are used.
"I'm
now convinced that any information coming out of the government is
suspect," says Ms. Rosenbaum, who is a staff member at the Drug Policy
Alliance, which opposes current drug policy.
The
controversy comes at a time when researchers like Marc Laruelle at Columbia
believe that they are on the brink of understanding how Ecstasy affects the
brain.
A new, more
accurate radioactive marker is being used that scientists say will produce much
more reliable brain scans. "I think it's very important that scientists
behave in a way that's going to increase the trust of the public," says
Dr. Laruelle.
Last month
a study into the therapeutic possibilities of Ecstasy sponsored by Mr. Doblin's
organization was given final government approval. His goal is to make MDMA into
a prescription medicine for the treatment of post-traumatic stress disorder.
"We've
got megamillions going into the demonization of Ecstasy," Mr. Doblin says,
"and all we need is $5-million to do the clinical trials that will be
necessary to provide the data to decide if this drug will be a helpful medicine
to many, many people."
The new
director of NIDA, Nora D. Volkow, worries that the retraction has sent the
message that Ecstasy has been proved harmless, which is not true.
She says
she is committed to making sure that the information the agency disseminates is
as accurate as possible. "The question that comes to light is, why has this
attracted so much attention?" she says. "And I think perhaps it's
because some people are exaggerating the adverse effects of drugs."
KEY MOMENTS IN ECSTASY RESEARCH
* 1912:
Methylenedioxymethamphetamine, or MDMA, is accidentally discovered by the German
pharmaceutical company Merck.
* Late
1970s: Some psychotherapists begin administering the drug to help their
patients relax and communicate more freely.
* 1985: At
the urging of the U.S. Drug Enforcement Administration, the drug, which is
being used recreationally and is now called Ecstasy, is banned.
* 1988:
George A. Ricaurte, a researcher at the Johns Hopkins University, publishes one
of the first studies linking Ecstasy to damage of serotonin neurons, which help
regulate mood.
* 1998: Dr.
Ricaurte publishes another study of the effects of Ecstasy on the brain.
* 2000: The
National Institute on Drug Abuse uses Dr. Ricaurte's 1998 study as the
centerpiece of a campaign against the drug, distributing 740,000 postcards
advertising its ill effects.
* September
2002: Dr. Ricaurte publishes his paper "Severe dopaminergic neurotoxicity
in primates after a common recreational dose of MDMA" in Science, saying
that Ecstasy causes severe damage to the dopamine systems of primates.
* March
2003: A German study is published that challenges Dr. Ricaurte's 1998 findings.
* June
2003: In response to a letter published in Science questioning his results, Dr.
Ricaurte defends his study.
* July
2003: Dr. Ricaurte writes to his backers at NIDA informing them of his inability
to replicate the results and his suspicions that bottles labeled MDMA actually
contained methamphetamine.
* September
2003: Nearly a year after its publication, Dr. Ricaurte retracts his 2002
paper.
(Source: The US Chronicle of Higher Education Fri, 27 Feb 2004 - Author:
Thomas Bartlett - http://www.mapinc.org/media/84)
"It
kind of gives science a black eye because people start to question whether NIDA
has an agenda,"