ecstasy
addiction
MDMA users may encounter
problems similar to those experienced by amphetamine and cocaine users,
including addiction. In addition to its rewarding effects, MDMA's psychological
effects can include confusion, depression, sleep problems, anxiety, and
paranoia during, and sometimes weeks after, taking the drug. Physical effects
can include muscle tension, involuntary teeth clenching, nausea, blurred
vision, faintness, and chills or sweating. Increases in heart rate and blood
pressure are a special risk for people with circulatory or heart disease.
MDMA-related fatalities at raves have been reported. The stimulant effects of
the drug, which enable the user to dance for extended periods, combined with
the hot, crowded conditions usually found at raves can lead to dehydration,
hyperthermia, and heart or kidney failure. MDMA use damages brain serotonin
neurons. Serotonin is thought to play a role in regulating mood, memory, sleep,
and appetite. Recent research indicates heavy MDMA use causes persistent memory
problems in humans. |
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long-term brain injury from use of
"ecstasy"
The designer drug
"Ecstasy," or MDMA, causes long-lasting damage to brain areas that are critical
for thought and memory, according to new research findings in the June 15 issue
of The Journal of Neuroscience. In an experiment with red squirrel
monkeys, researchers at The Johns Hopkins University demonstrated that 4 days
of exposure to the drug caused damage that persisted 6 to 7 years later. These
findings help to validate previous research by the Hopkins team in humans,
showing that people who had taken MDMA scored lower on memory tests.
"The serotonin system, which is compromised by MDMA, is fundamental to
the brain's integration of information and emotion," says Dr. Alan I. Leshner,
director of the National Institute on Drug Abuse (NIDA), National Institutes of
Health, which funded the research. "At the very least, people who take MDMA,
even just a few times, are risking long-term, perhaps permanent, problems with
learning and memory."
The researchers found that the nerve cells (neurons) damaged by MDMA
are those that use the chemical serotonin to communicate with other neurons.
The Hopkins team had also previously conducted brain imaging research in human
MDMA users, in collaboration with the National Institute of Mental Health,
which showed extensive damage to serotonin neurons.
MDMA (3,4-methylenedioxymethamphetamine) has a stimulant effect,
causing similar euphoria and increased alertness as cocaine and amphetamine. It
also causes mescaline-like psychedelic effects. First used in the 1980s, MDMA
is often taken at large, all-night "rave" parties.
In this new study, the Hopkins researchers administered either MDMA or
salt water to the monkeys twice a day for 4 days. After 2 weeks, the scientists
examined the brains of half of the monkeys. Then, after 6 to 7 years, the
brains of the remaining monkeys were examined, along with age-matched controls.
In the brains of the monkeys examined soon after the 2-week period,
Dr. George Ricaurte and his colleagues found that MDMA caused more damage to
serotonin neurons in some parts of the brain than in others. Areas particularly
affected were the neocortex (the outer part of the brain where conscious
thought occurs) and the hippocampus (which plays a key role in forming
long-term memories).
This damage was also apparent, although to a lesser extent, in the
brains of monkeys who had received MDMA during the same 2-week period but who
had received no MDMA for 6 to 7 years. In contrast, no damage was noticeable in
the brains of those who had received salt water.
"Some recovery of serotonin neurons was apparent in the brains of the
monkeys given MDMA 6 to 7 years previously," says Dr. Ricaurte, "but this
recovery occurred only in certain regions, and was not always complete. Other
brain regions showed no evidence of recovery whatsoever."
ecstasy
damages the brain and impairs memory in humans
A NIDA-supported study has provided the first direct evidence that
chronic use of MDMA, popularly known as "ecstasy," causes brain damage in
people. Using advanced brain imaging techniques, the study found that MDMA
harms neurons that release serotonin, a brain chemical thought to play an
important role in regulating memory and other functions. In a related study,
researchers found that heavy MDMA users have memory problems that persist for
at least 2 weeks after they have stopped using the drug. Both studies suggest
that the extent of damage is directly correlated with the amount of MDMA use.
"The message from these studies is that MDMA does change the brain and
it looks like there are functional consequences to these changes," says Dr.
Joseph Frascella of NIDA's Division of Treatment Research and Development. That
message is particularly significant for young people who participate in large,
all-night dance parties known as "raves," which are popular in many cities
around the nation. NIDA's epidemiologic studies indicate that MDMA
(3,4-methylenedioxymethamphetamine) use has escalated in recent years among
college students and young adults who attend these social gatherings.
 
These brain scans show
the amount of serotonin activity over a 40-minute period in a non-MDMA user
(left) and an MDMA user (right). Dark areas in the MDMA user's brain show
damage due to chronic MDMA use.
In the brain imaging study, researchers used positron emission
tomography (PET) to take brain scans of 14 MDMA users who had not used any
psychoactive drug, including MDMA, for at least 3 weeks. Brain images also were
taken of 15 people who had never used MDMA. Both groups were similar in age and
level of education and had comparable numbers of men and women.
In people who had used MDMA, the PET images showed significant
reductions in the number of serotonin transporters, the sites on neuron
surfaces that reabsorb serotonin from the space between cells after it has
completed its work. The lasting reduction of serotonin transporters occurred
throughout the brain, and people who had used MDMA more often lost more
serotonin transporters than those who had used the drug less.
Previous PET studies with baboons also produced images indicating MDMA
had induced long-term reductions in the number of serotonin transporters.
Examinations of brain tissue from the animals provided further confirmation
that the decrease in serotonin transporters seen in the PET images corresponded
to actual loss of serotonin nerve endings containing transporters in the
baboons' brains. "Based on what we found with our animal studies, we maintain
that the changes revealed by PET imaging are probably related to damage of
serotonin nerve endings in humans who had used MDMA," says Dr. George Ricaurte
of The Johns Hopkins Medical Institutions in Baltimore. Dr. Ricaurte is the
principal investigator for both studies, which are part of a clinical research
project that is assessing the long-term effects of MDMA.
"The real question in all imaging studies is what these changes mean
when it comes to functional consequences," says NIDA's Dr. Frascella. To help
answer that question, a team of researchers, which included scientists from
Johns Hopkins and the National Institute of Mental Health who had worked on the
imaging study, attempted to assess the effects of chronic MDMA use on memory.
In this study, researchers administered several standardized memory tests to 24
MDMA users who had not used the drug for at least 2 weeks and 24 people who had
never used the drug. Both groups were matched for age, gender, education, and
vocabulary scores.
The study found that, compared to the nonusers, heavy MDMA users had
significant impairments in visual and verbal memory. As had been found in the
brain imaging study, MDMA's harmful effects were dose-related and the more MDMA
people used, the greater difficulty they had in recalling what they had seen
and heard during testing.
The memory impairments found in MDMA users are among the first
functional consequences of MDMA-induced damage of serotonin neurons to emerge.
Recent studies conducted in the United Kingdom also have reported memory
problems in MDMA users assessed within a few days of their last drug use. "Our
study extends the MDMA-induced memory impairment to at least 2 weeks since last
drug use and thus shows that MDMA's effects on memory cannot be attributed to
withdrawal or residual drug effects," says Dr. Karen Bolla of Johns Hopkins,
who helped conduct the study.
The Johns Hopkins/NIMH researchers also were able to link poorer
memory performance by MDMA users to loss of brain serotonin function by
measuring the levels of a serotonin metabolite in study participants' spinal
fluid. These measurements showed that MDMA users had lower levels of the
metabolite than people who had not used the drug; that the more MDMA they
reported using, the lower the level of the metabolite; and that the people with
the lowest levels of the metabolite had the poorest memory performance. Taken
together, these findings support the conclusion that MDMA-induced brain
serotonin neurotoxicity may account for the persistent memory impairment found
in MDMA users, Dr. Bolla says.
Research on the functional consequences of MDMA-induced damage of
serotonin-producing neurons in humans is at an early stage, and the scientists
who conducted the studies cannot say definitively that the harm to brain
serotonin neurons shown in the imaging study accounts for the memory
impairments found among chronic users of the drug. However, "that's the
concern, and it's certainly the most obvious basis for the memory problems that
some MDMA users have developed," Dr. Ricaurte says.
Findings from another Johns Hopkins/NIMH study now suggest that MDMA
use may lead to impairments in other cognitive functions besides memory, such
as the ability to reason verbally or sustain attention. Researchers are
continuing to examine the effects of chronic MDMA use on memory and other
functions in which serotonin has been implicated, such as mood, impulse
control, and sleep cycles. How long MDMA-induced brain damage persists and the
long-term consequences of that damage are other questions researchers are
trying to answer. Animal studies, which first documented the neurotoxic effects
of the drug, suggest that the loss of serotonin neurons in humans may last for
many years and possibly be permanent. "We now know that brain damage is still
present in monkeys 7 years after discontinuing the drug," Dr. Ricaurte says.
"We don't know just yet if we're dealing with such a long-lasting effect in
people." |