High Price (38 page)

The reporting of brain imaging findings has been especially misleading. On July 20, 2004, for example, the
New York Times
printed an article titled,
THIS IS YOUR BRAIN ON METH: A
“FOREST FIRE” OF DAMAGE.
It stated, “People who do not want to wait for old age to shrink their brains and bring on memory loss now have a quicker alternative—abuse methamphetamine . . . and watch the brain cells vanish into the night.” This conclusion was based on a study that used magnetic resonance imaging (MRI) to compare brain sizes of methamphetamine addicts with non-drug-using healthy people.
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The researchers also looked at the correlation between memory performance and several brain structural sizes. They found that methamphetamine users’ right cingulate gyrus and hippocampus were smaller than those of controls by 11 and 8 percent, respectively. Memory performance on only
one
of four tests was correlated with hippocampal size (that is, individuals with larger hippocampal volume performed better). As a result, the researchers concluded, “chronic methamphetamine abuse causes a selective pattern of cerebral deterioration that contributes to impaired memory performance.” This interpretation, as well as the one printed in the
Times
article, is inappropriate for several reasons.

First, brain images were collected at only one time point for both groups of participants. This makes it virtually impossible to determine whether methamphetamine use caused “cerebral deterioration,” because there might have been differences between the groups even before methamphetamine was ever used. Second, the non–drug users had significantly higher levels of education than methamphetamine users (15.2 versus 12.8 years, respectively); it is well established that higher levels of education lead to better memory performance. Third, there were no data comparing methamphetamine users with controls on any memory task. This, in itself, precludes the researchers from making statements regarding impaired memory performance caused by methamphetamine. Nonetheless, the only statistically significant cognitive finding was a
correlation
of hippocampal volume and performance on one of the four tasks. This finding is the basis for the claim that methamphetamine users had memory impairments, because the hippocampus is known to play a role in some long-term memory; but other brain areas are also involved in processing long-term memory. The size of these other areas was not different between the groups. Finally, the importance on everyday functioning of the brain differences is unclear because an 11 percent difference between individuals, for example, is most likely within the normal range of brain structure sizes.

This example is not unique. The brain imaging literature is replete with a general tendency to characterize any brain differences as dysfunction caused by methamphetamine (as well as other drugs), even if differences are within the normal range of human variability.
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It would be like comparing the brains of police officers who have less education with those of college professors who have obtained a PhD, and concluding that the officers are cognitively impaired as a result of any differences that might be noted. This simplistic thinking is the main thrust behind the notion that drug addiction is a brain disease. It certainly isn’t a brain disease like Parkinson’s disease or Alzheimer’s disease. In the case of these illnesses, one can look at the brains of affected individuals and make pretty good predictions about the illness involved. We are nowhere near being able to distinguish the brain of a drug addict from that of a non–drug addict.

Because the literature wasn’t as informative as I’d hoped, I wrote and received a grant to study larger methamphetamine doses in individuals snorting the drug. These laboratory studies detailed the immediate and short-term effects of the drug on measures of cognitive functioning, mood, sleep, blood pressure, heart rate, and the drug’s addictiveness. I tested doses up to 50 mg, which were, at the time, the largest doses tested in people. All of the drug doses were given in a double-blind manner—the research participants didn’t know whether they were getting placebo or real methamphetamine, nor did the medical staff monitoring the sessions. The research participants were carefully selected to make sure they were in excellent medical condition. All were addicted to methamphetamine and used more than 100 mg of the drug on a weekly basis. I wanted to make sure that I was not exposing them to more drug in the lab than they used outside the lab. Similar to the cocaine studies I had previously conducted, we intentionally recruited people who were not seeking treatment, because we felt it was unethical to give methamphetamine to someone trying to stop using.

In the first experiment, we simply had research participants snort one dose of methamphetamine while our medical team carefully monitored their vital signs for twenty-four hours. We also asked the participants to do cognitive tests and rate their mood before and several hours after the drug was given. The findings were consistent with data from our previous studies when we gave the drug by mouth.
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Participants reported feeling more euphoric and their cognitive functioning was improved. These effects lasted about four hours. The drug also caused significant increases in blood pressure (BP) and heart rate that lasted for up to twenty-four hours. The maximum levels were about 150/90 (BP) and 100 (beats per minute). While these elevations were undoubtedly significant, they were well below levels obtained when most people are engaged in a vigorous activity such as physical exercise. Another finding was that the drug reduced the amount of time our participants slept.
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For example, when they took placebo, participants got about eight hours of sleep on that evening. But when the 50 mg dose was given, they got only six hours of sleep. Together, the results indicated that a large snorted dose of methamphetamine produced expected effects. The drug didn’t keep people up for consecutive days, it didn’t dangerously elevate their vital signs, nor did it impair their judgment. Around the same time, other researchers were studying the drug when it was injected or smoked and they were getting similar results.
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The human laboratory data were at odds with anecdotal reports and conventional wisdom. Maybe I hadn’t asked the right question. One of the most popular beliefs about methamphetamine is that it is highly addictive, more so than any other drug. In the next set of experiments, I set out to address this issue. Under one condition, I gave methamphetamine addicts a choice between taking a big hit of methamphetamine (50 mg) or five dollars in cash. They took the drug on about half of the opportunities. But when I increased the amount of money to twenty dollars, they almost never chose the drug.
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I had gotten similar results with crack cocaine addicts in an earlier study.
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This told me that the addictive potential of methamphetamine was not as had been claimed; its addictiveness wasn’t extraordinary. My results also showed me that methamphetamine addicts, just like crack addicts, can and do make rational decisions, even when faced with a choice to take the drug or not. This was consistent with the literature assessing cognitive functioning of methamphetamine users, but as noted above, only if you looked carefully.
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Still, the popular view of methamphetamine remained unchanged. Most media portrayals continued to emphasize unrealistic effects and exaggerate the harms associated with the drug. For example, in January 2010, NPR ran a story titled, “This Is Your Face on Meth, Kids.” The story described a California sheriff who was trying to stop young people from experimenting with methamphetamine. With the help of a programmer, he developed a computer program that digitally altered teenagers’ faces to show them what they would look like after using methamphetamine for six, twelve, and thirty-six months. These young people watched their images change from those of healthy, vibrant individuals to faces marred by open scabs, droopy skin, and hair loss. They were told that these were the physiological effects of using methamphetamine. Ninety percent of individuals who tried methamphetamine once, they were also told, would become “addicted.” How could such inaccurate information be given to naive students, let alone be reported on NPR, I thought.

There is no empirical evidence to support the claim that methamphetamine causes one to become physically unattractive. Of course, there have been the pictures of unattractive methamphetamine users in media accounts about how the drug is ravaging some rural town. You may have also seen the infamous “meth mouth” images (extreme tooth decay). But consider this: methamphetamine and Adderall are essentially the same drug. Both drugs restrict salivary flow, leading to xerostomia (dry mouth), one proposed mechanism of meth mouth. Adderall and generic versions are used daily and frequently prescribed—each year they are among the top one hundred most prescribed drugs in the United States—yet there are no published reports of unattractiveness or dental problems associated with their use. The physical changes that occurred in the dramatic depictions of individuals before and after their methamphetamine use are more likely related to poor sleep habits, poor dental hygiene, poor nutrition and dietary practices, and media sensationalism. With regard to the addictiveness of methamphetamine, the best available information clearly shows that the majority of people who try methamphetamine will not become addicted.
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The media and general public were not the only ones caught up in the methamphetamine hysteria. Many scientists were also bamboozled. From 2006 to 2010, I was a member of an NIH grant review committee. The committee was composed of about forty scientists with diverse expertise. One of our main tasks was to evaluate the scientific merits of research grant proposals submitted by drug abuse scientists. We frequently reviewed proposals seeking funds to study methamphetamine. Many of the proposals argued that the drug produced brain damage, while others pointed to the cognitive impairments caused by methamphetamine. They seemed to have accepted, as a foregone conclusion, that any use of this drug was destructive. These arguments were compelling to some on the review committee. The problem was that they were not supported by evidence; instead they were misrepresentations of the data. I am not suggesting that the scientists who wrote the grants did this intentionally. I don’t think they did. I do believe, however, that the scientists understood quite well the mission of their proposed funder—National Institute on Drug Abuse (NIDA)—and this understanding shaped their grant proposal.

NIDA’s mission “is to lead the Nation in bringing the power of science to bear on
drug abuse and addiction
.” Drug abuse and addiction are only limited and negative aspects of the many effects produced by drugs. Of course, drugs like methamphetamine produce other effects, including positive ones such as improved cognitive performance and mood, but that isn’t a part of NIDA’s mission. And scientists seeking research money from NIDA are well aware that they must emphasize the negative effects of drugs in order to get funded. Upton Sinclair’s famous quote aptly describes this situation: “It is difficult to get a man to understand something when his salary depends upon his not understanding it.”
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Consider also that NIDA funds more than 90 percent of all research on the major drugs of abuse. This means that the overwhelming majority of information on drugs published in the scientific literature, textbooks, and popular press is biased toward the negative aspects of drug use.

I am not suggesting that the negative consequences of drug use shouldn’t be the focus of research funded by NIDA. Focusing on the pathological aspects of drug use is extremely important for developing effective treatments for drug addiction. But the current disproportionate focus on the bad effects of drugs tends to leave us with a skewed perspective. It has helped to create an environment where certain drugs are deemed evil and any use of these drugs is considered pathological. As I have repeatedly pointed out throughout this book, most people who use any drug do so without problems. This is not an endorsement for the legalization of drugs. It’s just a fact. The near-exclusive focus on the negative effects of drugs has also contributed to a situation where there is an unwarranted and unrealistic goal of eliminating certain types of drug use at any cost. Too often marginalized groups absorb the bulk of the cost. It has been well documented that certain minority communities have been particularly affected by our zeal to get rid of certain drugs. The human cost of this misguided approach is incalculable, as hundreds of thousands of men and women, including my own family members, languish in prison as a result.

In an effort to draw attention to the misinterpretations that plague the methamphetamine scientific literature, I wrote a critical review article that assessed more than fifty peer-reviewed research studies on the short- and long-term effects of the drug on brain and cognitive functioning.
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I concluded that methamphetamine addicts were overwhelmingly within the normal range on both measures. But, despite this fact, there seems to be a propensity to interpret any cognitive and/or brain difference(s) as clinically significant abnormalities.

Before any paper is published in a scientific journal, experts in the field must review it anonymously. These reviews are often brutal. They sometimes question your intellectual capacity to be employed as a scientist. So, when I received the reviews for my paper I was expecting harsh criticism because I was essentially calling into question an entire body of research. To my surprise, the reviewers’ comments were extremely laudatory: “This review is comprehensive and extremely well written. Dr. Hart and colleagues certainly challenge the status quo and should be applauded for writing a provocative paper and taking what will surely be characterized as an unpopular position. . . . The general message is somewhat of a wake-up call to the field. . . .” It’s too soon to know the exact impact the paper will have on the field, but shortly after its publication,
Scientific American
highlighted it in an article that questioned whether the methamphetamine hysteria is limiting the availability of effective medicines.
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