Meth Mouth and Other Meth Myths

A new report shows how the hazards of "the most dangerous drug in America" have been grossly exaggerated.

Alberto Gonzales, George W. Bush's attorney general, called it "the most dangerous drug in America." A physician quoted by The New York Times described it as "the most malignant, addictive drug known to mankind." A police captain told the Times it "makes crack look like child's play, both in terms of what it does to the body and how hard it is to get off."

Meanwhile, doctors routinely prescribe this drug and others very similar to it for conditions such as narcolepsy, obesity, and attention deficit hyperactivity disorder (ADHD). If these drugs are as dangerous as Gonzales et al. claim, how can millions of Americans—including schoolchildren—safely consume them on a regular basis?

Columbia neuropsychopharmacologist Carl Hart explores that puzzle in a new report that aims to separate fact from fiction on the subject of methamphetamine. Hart and his two co-authors—University of North Carolina at Wilmington philosopher Don Habibi and Joanne Csete, deputy director of the Open Society Global Drug Policy Program—argue that hyping the hazards posed by meth fosters a punitive and counterproductive overreaction similar to the one triggered by the crack cocaine panic of the 1980s, the consequences of which still afflict our criminal justice system. "The data show that many of the immediate and long-term harmful effects caused by methamphetamine use have been greatly exaggerated," Hart et al. write, "just as the dangers of crack cocaine were overstated nearly three decades ago."

The report, published by the Open Society Foundations, begins by considering the addictive potential of methamphetamine. Despite all the talk of a "meth epidemic," the drug has never been very popular. "At the height of methamphetamine's popularity," Hart et al. write, "there were never more than a million current users of the drug in the United States. This number is considerably lower than the 2.5 million cocaine users, the 4.4 million illegal prescription opioid users, or the 15 million marijuana smokers during the same period." Furthermore, illicit methamphetamine use had been waning for years at the point when Newsweek identified "The Meth Epidemic" as "America's New Drug Crisis." 

Although methamphetamine is commonly portrayed as irresistible and inescapable, it does not look that way when you examine data on patterns of use. Of the 12.3 million or so Americans who have tried it, according to the National Survey on Drug Use and Health (NSDUH), about 1.2 million (9.4 percent) have consumed it in the last year, while less than half a million (3.6 percent) have consumed it in the last month (the standard definition of "current" use). In other words, more than 96 percent of the people who have tried "the most addictive drug known to mankind" are not currently using it even as often as once a month. A 2009 study based on NSDUH data found that 5 percent of nonmedical methamphetamine consumers become "dependent" within two years. Over a lifetime, Hart et al. say, "less than 15 percent" do. 

Even heavy methamphetamine users have more self-control than is commonly thought, as Hart's own research shows:

Under one condition, methamphetamine-dependent individuals were given a choice between taking a big hit of methamphetamine (50 mg) or $5 in cash. They chose the drug on about half of the opportunities. But when we increased the amount of money to $20, they almost never chose the drug. 

Laboratory research also has found that "d-amphetamine and methamphetamine produce nearly identical physiological and behavioral effects," Hart et al. write. "They both increase blood pressure, pulse, euphoria, and desire to take the drug in a dose-dependent manner. Essentially, they are the same drug." That observation helps put methamphetamine's risks in perspective, since d-amphetamine, a.k.a. dextroamphetamine, is one of the main ingredients in Adderall, a stimulant widely prescribed for ADHD. Hart et al. note that methamphetamine, like dextroamphetamine, increases heart rate and blood pressure, but "well below levels obtained when engaged in a rigorous physical exercise." 

When given to research subjects, "the drug didn't keep people up for consecutive days, it didn't dangerously elevate their vital signs, nor did it impair their judgment." Contrary to tales of meth-induced murder and mayhem, "There is no empirical evidence that suggests that even long-term users of methamphetamine pose a threat to those around them." Hart et al. note that "incredible anecdotes are usually disseminated uncritically by the popular press and accepted as sound evidence by an undiscerning public." One example from my book Saying Yes: In 1994 Reader's Digest described the rape and murder of an 18-month-old girl in California as a "meth-related child killing." Yet neither newspaper coverage of the case nor the California Supreme Court's 87-page decision rejecting the murderer's appeal made any mention of the drug. 

What about long-term effects? Shocking as it may be to anyone who has accepted at face value the gruesome images featured in anti-meth propaganda, the drug does not make you ugly. "Meth mouth"—the extreme tooth decay supposedly characteristic of heavy users—is said to be caused by meth-induced dry mouth. Yet widely consumed prescription stimulants such as Adderall produce the same side effect, Hart et al. note, and "there are no published reports of unattractiveness or dental problems associated with their use." Allegedly meth-related physical characteristics such as rotten teeth, thinning hair, and bad complexions, they say, "are more likely related to poor sleep habits, poor dental hygiene, poor nutrition and dietary practices." 

Hart also questions research linking heavy methamphetamine use to brain damage. He argues that studies in which large doses are repeatedly given to animals that have never been exposed to the drug before bear little resemblance to human consumption patterns, which feature gradual escalation. "This difference is not trivial," Hart et al. write, "because the harmful neurobiological and behavioral changes that occur in response to repeated large doses of methamphetamine can be prevented with prior exposure to several days of escalating doses." 

In studies of people, Hart says, researchers exaggerate the practical significance of their findings and fail to properly control for pre-existing difference between meth users and the general population. "The brain imaging literature is replete with a general tendency to characterize any brain differences as dysfunction caused by methamphetamine," Hart et al. write, "even if differences are within the normal range of human variability." 

Over-the-top warnings about methamphetamine—encapsulated in the slogan "Meth: Not Even Once"—aim to scare people away from a drug that might harm them (but probably won't). By contrast, Hart argues, exaggerating the hazards posed by methamphetamine causes definite damage by encouraging harsh criminal penalties (such as a five-year mandatory minimum for five grams), fostering distrust of accurate warnings about drugs, suppressing useful information that could reduce drug-related harm, driving users toward more dangerous routes of administration (as efforts to reduce meth purity, if successful, predictably would do), and justifying ineffective policies that impose substantial costs on large numbers of people for little or no benefit (such as restrictions on the methamphetamine precursor pseudoephedrine, a cheap, safe, and effective decongestant that is now absurdly difficult to obtain). In other words, hyperbole hurts.

This article was originally published by Forbes.