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Does MDMA/Ecstasy cause Parkinson’s disease (PD)?
Or does it help cure it? Both questions have been raised
in the past about MDMA and the chronic,
debilitating movement disorder.
In September 2002, NIDA-sponsored researchers George Ricaurte and
Una McCann reported some widely-publicized findings in the journal
Science claiming that MDMA damaged dopamine neurons in primates,
speculating that it could even lead to Parkinson’s disease (PD). Prior to
this publication, there was at least one study showing signs of PD among
Ecstasy users (Mintzer et al. 1999), but the significance of this remained
controversial (Baggott et al. 1999; Borg 1999). The findings published in
Science were considered evidence supporting a link between MDMA and
PD, and several other cases of PD in former Ecstasy users appeared soon
after their publication (Kuniyoshi and Jankovic 2003; O’Suilleabhain and
Giller 2003). Imaging studies of Ecstasy users published before these
findings failed to find reductions in dopamine transporters (Reneman et al.
2002; Semple et al. 1999), and a post-mortem investigation also found
reduced serotonin neurons, but no reduction in dopamine neurons, in a
heavy Ecstasy user (Kish et al. 2000).
However, as it turned out, Ricaurte and colleagues retracted their findings
a year later, once it was discovered that they had administered methamphetamine,
and not MDMA, to the monkeys and baboons in the study.
The controversy continued over what conclusions, if any, can be drawn
from case reports of PD in Ecstasy users (Jerome et al. 2004; Kish 2003).
Later, when the same team of investigators gave monkeys the same or
higher doses of genuine MDMA, they failed to find any dopamine toxicity,
even when finding serotonin toxicity (Mechan et al. 2005). Monkeys that
gave themselves MDMA over an 18-month period also did not have any
dopamine toxicity (Fantegrossi et al. 2004).
From these reports, we can be pretty
sure that MDMA does not cause
Parkinson’s disease. The next question is:
can it treat PD? Recently, studies conducted
at Duke University Medical Center
(Sotnikova et al. 2005) found that MDMA
was the most effective of 60 drugs tested
in a mouse model of PD. Previously, other
researchers reported reversal of PD-like
symptoms, such as being unable to move
or being stuck in one position, in rats and
monkeys given MDMA or MDMA-like
compounds (MDE, MDA), as well as nonentactogenic
amphetamines (Banjaw et al.
2003, Iravani et al. 2003; Lebsanft et al.
2003; Lebsanft et al. 2005; Schmidt et al.
2002). In the previous studies, the researchers
modeled PD either by giving
animals a drug that interferes with the
dopamine system, or they damaged the
animal’s dopamine system. The Duke team
simulated PD by looking at genetically
engineered mice lacking the dopamine
transporter (the molecule that recycles
dopamine) before and after giving them a
drug that stopped them from making
dopamine. They examined a large number
of compounds, including drugs that
influenced the serotonin and dopamine
systems. Very high doses of MDMA
improved PD-like symptoms in the mice,
and lower doses of MDMA combined with
anti-PD drugs, such as carbidopa or LDOPA,
also helped the dopamine-deficient
mice.
Much of this research seems to have
been instigated by the account of Tim
Lawrence, a British man with young-onset
PD who appeared in the media claiming
that he gained symptomatic relief after
MDMA/Ecstasy use (see Concar 2002;
Margolis 2001). However, the problem
that Ecstasy apparently fixed was not PD
itself, but a side effect of PD medication
(dyskinesia, a movement problem that
includes twitching). It is possible that
MDMA helped Lawrence by directly or
indirectly boosting dopamine function
(see comments by D. Nichols; http://
www.maps.org/mdma/nichols.html), but
some findings in the monkey and mouse
studies suggest that MDMA and related
drugs might help through a different route
unrelated to dopamine. The Duke team
believes that MDMA and other drugs may
help treat PD symptoms through their
action on the newly discovered trace
amine receptor.
However, none of the findings
described above suggest that MDMA or
any related entactogens are going to be a
suitable PD medication. Even if low doses
of MDMA do treat PD when combined
with other medications, they are not likely
to be a viable, practical solution, since
daily dosing with MDMA is likely to
increase risks of potential neurotoxicity.
More to the point, unlike Tim Lawrence,
most people with PD are older and are
more likely to have, or be at risk for,
conditions that make using MDMA a bad
idea, such as heart problems or stroke risk.
In the initial tests performed by the
Duke team, the doses of MDMA used were
extremely high, bordering on acutely
toxic-in some cases up to sixty times
higher than doses that can be safely
administered to humans. They used doses
comparable to those used by humans in
later tests, but in these cases the researchers
combined MDMA with other drugs
that increase or enhance dopamine, such
as carbidopa or L-DOPA. Previous studies,
like that of Iravani and colleagues, used
lower doses, between 10 mg/kg and 12
mg/kg in marmosets, which are not lethal
but still probably neurotoxic.
There are at least four good reasons
not to encourage people to self-medicate
with street Ecstasy, and at least three for
not even doing so with pure MDMA.
These include general problems with the
identity and strength of anything bought
on the street, general health-related issues
(everything from tolerance to the possibility
of neurotoxicity arising from daily
dosing), and health issues in people with
Parkinson’s disease (cardiovascular
problems or hidden cerebrovascular
problems).
While the idea is intriguing, it’s
difficult to see MDMA or a known
entactogen being used as a treatment for
PD. One important avenue of research,
however, could be the use of an entactogen
as a “rescue” medication for dyskinesia, but
MAPS isn’t in a position to initiate such
research since we still have several MDMA
psychotherapy studies that need funding.
It is possible but unlikely that the future
treatment for PD might be an entactogen,
but it’s way too early to tell. •
(please see references in the Adobe Acrobat version of this file)
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