METH HYPE COULD UNDERMINE GOOD MEDICINE

Overstating The Dangers Of Methamphetamine May Impede Treatment Of
Drug Abusers, Asserts A Review By Columbia University Researchers

The 1936 film Reefer Madness developed a cult following because of its
over-the-top depiction of the evils of marijuana. Getting stoned and
going to a midnight showing became a ritual for many college students.

The recognition that pot is not a direct route to an asylum for the
criminally insane, as it was for one character in the film, fueled the
hilarity for late-night moviegoers. The divergence between perception
and reality has become an issue in recent years for other recreational
drugs.

Last month four scientists from Columbia University published an
analysis of previous studies on methamphetamine use that called into
question some of the purported damaging effects of the drug on brain
functioning. The review in Neuropsychopharmacology found that
short-term effects of the drug actually improve attention, as well as
visual and spatial perception, among other things.

Moreover, chronic users-the ones who would be expected to suffer
most-remain largely unimpaired. The researchers found that they
experience brain and cognitive changes "on a minority of measures" in
brain imaging and psychological tests. "Cognitive functioning
overwhelmingly falls within the normal range," the report states,
while adding that researchers' pre-existing assumptions about meth's
detrimental effects "should be reevaluated to document the actual
pattern of cognitive effects caused by the drug."

While recognizing the potential for abuse, the researchers emphasize
that misinterpretations of the scientific evidence can wrongly
stigmatize drug abusers and lead to misguided policymaking. One study,
for instance, asserted that meth abusers might be too cognitively
damaged to benefit from rehabilitative treatments, such as cognitive
behavioral therapies. "Findings from this review argue that such
concerns are unwarranted," the researchers state.

In Thailand, efforts to stem meth use have gone as far as banning all
amphetamines, a class of drug that is used medically for treatment of
ADHD and other conditions. "My main goal really was to make sure that
we are rigorous in the science before we are political," says Carl
Hart, a substance abuse researcher at Columbia who was the lead author
on the Neuropsychopharmacology paper. "I think, with meth, we have
been political." (Neuropsychopharmacology is part of Nature Publishing
Group, which also includes Scientific American.)

The article asserts that some of the misconceptions surrounding meth
go beyond findings on mental functioning. Drug education campaigns
often publish photographs of "meth mouth," severe tooth decay among
users because of the lack of saliva. But dry mouth is a condition
common to other drugs, such as the prescription antidepressant
Cymbalta and the ADHD medication Adderall.

Hart says he was impelled to do the research because of distortions of
the evidence for harm from crack cocaine. During the crack cocaine
epidemic in the 1980s and 1990s, pronouncements about lasting prenatal
harm to children whose mothers used the drug turned out to be
overblown: long-term effects on brain development and behavior were
fairly small, and children were sometimes ostracized or received
medical diagnoses that were mistakenly attributed to effects from the
drug.

The review by Hart and colleagues elicited a firm counterpoint from
National Institute on Drug Abuse director Nora Volkow, some of whose
research is critiqued in the Neuropsychopharmacology paper. "Because
of the far-reaching public health implications of this issue, it is
essential not to forget what we do know about meth-induced
neuropathology, which is plenty troubling," she says. Volkow points
out that the vascular effects of meth can lead to strokes and
hemorrhages. The drug, she notes, has also been shown to produce
inflammation, atrophy and structural changes in brain tissue.
"Similarly worrisome is a recent report of increased incidence of
Parkinson's diseases among individuals with a past history of
methamphetamine abuse [compared with] the general population," she
says, adding that meth abuse can be "neurotoxic to the human brain."

Hart responds that he and his colleagues were careful to consider the
full body of scientific literature, including animal studies. He
points out that many animal studies used to extrapolate possible
deleterious cognitive effects in humans had administered large amounts
of methamphetamine from the outset, a regimen unlike the gradual
escalation in dosing undertaken by illicit drug users, which avoids
these consequences. The article emphasizes that serious medical
consequences, such as paranoia and hypertension leading to stroke, are
rare and only result from sustained ingestion of very large doses.

Meth's persistent bad boy reputation means that medical marijuana
dispensaries will not be expanding their offerings to include speed
any time soon. Still, the idea is not as totally outlandish as it might seem.

A much cited commentary that appeared in Nature in December 2008-an
article co-authored by neuroscientists and ethicists-raised the
prospect of routine use of "cognitive enhancement" drugs by the
general public if they could be proved safe.

The few drugs already on the market that come closest to meeting the
definition of cognitive enhancers include Adderall (dextroamphetamine
and amphetamine) and Ritalin (methylphenidate), close chemical cousins
of methamphetamine. Ritalin and Adderall, in fact, have developed a
reputation as executive's little helpers in the business world and
were cited in the Nature commentary.

Hart and his colleagues never suggested that methamphetamine could
serve as a pick-me-up for meeting pending work deadlines. Their
review, though, looked at more than 10 studies that found that
short-term use of meth actually improves several cognitive measures,
precisely the kind of evidence the authors of the Nature article were
calling for when considering the merits of enhancement.

The debate over methamphetamine, used widely by soldiers during World
War II, reveals the ambivalent societal relationship toward
potentially addictive compounds that can also serve as performance
boosters. The hate-love relationship will likely continue into the
indefinite future.