Category: Crystal Meth

The economic cost of methamphetamine use in the United States reached $23.4 billion in 2005, including the burden of addiction, premature death, drug treatment and many other aspects of the drug, according to a new RAND Corporation study.

The RAND study is the first effort to construct a comprehensive national assessment of the costs of the methamphetamine problem in the United States.

"Our findings show that the economic burden of methamphetamine abuse is substantial," said Nancy Nicosia, the study's lead author and an economist at RAND, a nonprofit research organization.

Although methamphetamine causes some unique harms, the study finds that many of the primary issues that account for the burden of methamphetamine use are similar to those identified in economic assessments of other illicit drugs.

Given the uncertainty in estimating the costs of methamphetamine use, researchers created a range of estimates. The lowest estimate for the cost of methamphetamine use in 2005 was $16.2 billion, while $48.3 billion was the highest estimate. Researchers' best estimate of the overall economic burden of methamphetamine use is $23.4 billion

The study was sponsored by the Meth Project Foundation, a nonprofit group dedicated to reducing first-time methamphetamine use. Additional support was provided by the National Institute on Drug Abuse.

"We commissioned this study to provide decision makers with the best possible estimate of the financial burden that methamphetamine use places on the American public," said Tom Siebel, founder and chairman of the Meth Project. "This is the first comprehensive economic impact study ever to be conducted with the rigor of a traditional cost of illness study, applied specifically to methamphetamine. It provides a conservative estimate of the total cost of meth, and it reinforces the need to invest in serious prevention programs that work."

The RAND analysis found that nearly two-thirds of the economic costs caused by methamphetamine use resulted from the burden of addiction and an estimated 900 premature deaths among users in 2005. The burden of addiction was measured by quantifying the impact of the lower quality of life experienced by those addicted to the drug.

Crime and criminal justice expenses account for the second-largest category of economic costs, according to researchers. These costs include the burden of arresting and incarcerating drug offenders, as well as the costs of additional non-drug crimes caused by methamphetamine use, such as thefts committed to support a drug habit.

Other costs that significantly contribute to the RAND estimate include lost productivity, the expense of removing children from their parents' homes because of methamphetamine use and spending for drug treatment.

One new category of cost captured in the analysis is the expense associated with the production of methamphetamine. Producing methamphetamine requires toxic chemicals that can result in fire, explosions and other events. The resulting costs include the injuries suffered by emergency personnel and other victims, and efforts to clean up the hazardous waste generated by the production process.

Researchers caution that their estimates are in some cases based on an emerging understanding of methamphetamine's role in these harms and should be further refined as understanding of these issues matures. The RAND report also identifies costs that cannot yet be adequately quantified.

"Estimates of the economic costs of illicit drug use can highlight the consequences of illegal drug use on our society and focus attention on the primary drivers of those costs," Nicosia said. "But more work is needed to identify areas where interventions to reduce these harms could prove most effective."

Methamphetamine is a highly addictive substance that can be taken orally, injected, snorted or smoked. While national surveys suggest that methamphetamine use is far from common, there is evidence that the harms of methamphetamine may be concentrated in certain regions. One indicator of the problem locally is treatment admissions. Methamphetamine was the primary drug of abuse in 59 percent of the treatment admissions in Hawaii in 2004 and accounted for 38 percent of such admissions in Arizona in 2004.

The report, "The Economic Costs of Methamphetamine Use in the United States – 2005," is available as a PDF. Other authors of the report are Rosalie Liccardo Pacula, Beau Kilmer, Russell Lundberg and James Chiesa.

An independent review investigating the effectiveness of a publicly funded graphic anti-methamphetamine advertising campaign has found that the campaign has been associated with many negative outcomes. The review was published in the December issue of Prevention Science, a peer reviewed journal of the Society for Prevention Research (SPR).

The Montana Meth Project (MMP) was created in 2005 to reduce methamphetamine use in Montana via graphic advertising showing extreme consequences of using meth "just once." Initially the ad campaign was privately funded, but it has since received millions of dollars in state and federal support as the MMP has promoted the ad campaign as a resounding success to policy makers and the media. Based on the apparent success of the ad campaign in Montana, it has since been implemented in other states including Arizona, Idaho, and Illinois, with more states to follow.

The negative outcomes identified in the review include: following six months exposure to the MMP's graphic ads, there was a threefold increase in the percentage of teenagers who reported that using meth is not a risky behaviour; teenagers were four times more likely to strongly approve of regular meth use; teenagers were more likely to report that taking heroin and cocaine is not risky; and up to 50% of teenagers reported that the graphic ads exaggerate the risks of using meth.

The review found that the MMP overlooked these unflattering results when promoting their research findings to policymakers and the media. Instead, the MMP focused on select positive findings.

The author of the review, David Erceg-Hurn, who is currently completing his PhD in Clinical Psychology at the University of Western Australia, came across the Meth Project while conducting research on graphic tobacco advertising. There was a mention of the Meth Project in an article he read. Erceg-Hurn followed up on that mention and closely scrutinized the Meth Project's research reports. He said that it is important for organizations that are funding or considering funding the MMP's ad campaign to be made aware of all of the MMP's findings – positive and negative. To date, this has not happened.

Erceg-Hurn also criticized claims that the ad campaign has been responsible for reducing meth use in Montana. "Meth use had been declining for at least six years before the ad campaign commenced, which suggests that factors other than the graphic ads cause reductions in meth use. Another issue is that the launch of the ad campaign coincided with restrictions on the sale of cold and flu medicines commonly used in the production of meth. This means that drug use could be declining due to decreased production of meth, rather than being the result of the ad campaign."

Erceg-Hurn also pointed out in his review that due to the way the MMP has conducted their research, it is impossible to conclude that the ad campaign had any effect on meth use. To draw such conclusions would require much more rigorous research. This would involve examining two groups of teenagers that were equivalent in terms of drug use, exposing only one group to the graphic ads, and then examining any differences between the groups in their drug use.

The theory underlying the MMP's ad campaign was also criticized by Erceg-Hurn. "The idea behind the ad campaign is that teenagers take meth because they believe it is socially acceptable, and not risky – and the ads are meant to alter these perceptions. However, this theory is flawed because the Meth Project's own data shows that 98% of teenagers strongly disapproved of meth use and 97% thought using meth was risky before the campaign started."

The review also points out that considerable prior research has found that large anti-drug advertising campaigns can be ineffective and sometimes harmful. For example, the National Youth Anti-Drug Media Campaign has cost taxpayers over $1.5 billion since 1998. A Government Accountability Office report found that the ad campaign has not reduced drug use. The only significant results were in an unfavorable direction – some youths reported an increase in marijuana use upon increased exposure to the campaign.

Erceg-Hurn concluded in his Prevention Science review that based on current evidence, continued public funding and rollout of Montana-style anti-methamphetamine graphic ad campaign programs is inadvisable.

Teens who have never done drugs, but engage in other risky behaviours such as drinking, smoking and being sexually active, are more likely to use crystal meth, medical researchers at the University of Alberta have concluded. Among teens already doing other drugs, those with unstable family environments are most likely to do crystal meth, found the research team led by Dr. Terry Klassen, a professor in the Department of Pediatrics in the Faculty of Medicine & Dentistry.

The researchers conducted an exhaustive search of the literature on methamphetamine use, and analyzed the results of a dozen studies to get a big-picture idea of factors at the individual, family and community level associated with crystal meth use among children and adolescents.

"If risk factors for MA use could be identified, physicians and other health-care professionals who work with youth may be better equipped to identify MA users, and develop education and prevention programs that could be targeted to youth at greater risk for using MA," Klassen said.

The U of A article was recently published in the medical journal BMC Pediatrics.

The researchers divided children and adolescents into two groups: "low-risk" (no previous drug use) and "high-risk" (history of drug use or time in a juvenile detention centre). There were some clear patterns of risk factors associated with crystal meth use, they said.

In the low-risk group, the U of A team also found that boys were more likely to try crystal meth than girls, and being homosexual or bisexual was also a risk factor.

But in the high-risk group, more girls than boys used crystal meth. In this group, drinking was not associated with methamphetamine use, but a family history of alcohol abuse was. Child abuse was not found to be significant factor.

Having certain psychiatric conditions was a risk factor for both groups. Because of the nature of the studies involved, the U of A researchers say they could not determine if these factors cause young people to use crystal meth, only that they are associated with abuse of this drug.

"This systematic review presents the best available evidence regarding factors for methamphetamine use among youth," Klassen said. "Engaging in high-risk behaviour may be a gateway for methamphetamine use or vice-versa." While many of the results might appear to be common sense, Klassen says there is always value in testing widely held beliefs or assumptions.

"You don't know beforehand whether a hypotheses will be proven or disproven," he noted. "If we didn't engage in these kinds of studies, we wouldn't know for sure."

The findings clearly indicate that health-care workers and counsellors "need to conduct a holistic assessment that includes psychiatric, lifestyle and family history," the U of A study concluded.

The research is intended for health-care professionals, but parents can learn from it as well. "When they start to see a cluster of (factors) that probably is a situation where they should be paying a lot more attention to their children. It may be more of a wake-up call," Klassen said.

The researchers scoured more than 40 databases for relevant academic articles and clinical trials, scientific journals, papers presented at scientific meetings, and so-called "grey literature" – harder-to-find sources such as government reports on the topic, PhD theses, and so on. The team restricted its search English-language studies.

The initial search results yielded 2,376 potentially relevant studies. The researchers eventually narrowed down the results to 13 separate studies that fit the criteria of their review. Seven were done in North America and the rest in Asia. The majority were carried out within the last few years. Sample sizes ranged from 60 to 78,715.

Some findings from individual studies, highlighted by Klassen and his team:

Low-risk youth:

• The fewer years of education that youth had, the more likely they were to use crystal meth.
• Being sexually active was "significantly associated" with using crystal meth.
• Youth who smoked, drank or used heroin and other opiates were more likely to try crystal meth.
• When it came to mental health, low-risk youth with adjustment disorder, conduct disorder and attention deficit hyperactivity were much more likely to use crystal meth. However, oppositional defiance disorder, anxiety, depression, bipolar disorder and eating disorder were not significantly associated with crystal meth use in the low-risk group.
• Being homosexual or bisexual, disruptive parenting, peers using meth and family history of drug use were other risk factors among young people who had never used drugs before.

High- risk youth:

• "Strict parental monitoring was found to be protective for MA use among high-risk youth."
• A family history of alcohol abuse, crime or drug abuse was associated with crystal meth use.
• Receiving psychiatric treatment, more than two stints in a juvenile detention centre and a history of violence were "significantly associated" with crystal meth use.

A new study at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory suggests that vigabatrin (a.k.a. gamma vinyl-GABA, or GVG) blocks drug-seeking behavior in animals previously trained to associate methamphetamine with a particular environment.

Specifically, animals pre-treated with vigabatrin lost interest in spending time in a location where they had previously been given methamphetamine. The results will appear in the February 2009 issue of Synapse, now available online.

"Reinstatement of drug-seeking behavior after an extended period of abstinence is the number-one cause of drug-addiction relapse," said Brookhaven neuroanatomist Stephen Dewey, who led the research team. "This animal study suggests that vigabatrin could potentially prevent human methamphetamine addicts from relapsing."

According to the National Institute on Drug Abuse, methamphetamine is a very addictive stimulant that is quickly becoming an American public health epidemic. There is currently no effective treatment for methamphetamine addiction.

Vigabatrin is a pharmaceutical agent first tested as a possible treatment for a variety of addictions in animal studies led by Dewey at Brookhaven Lab. It is the only drug that has been shown to block any behavior associated with methamphetamine use, and is currently being tested by Catalyst Pharmaceutical Partners for safety and efficacy against cocaine and methamphetamine addiction in humans in Phase II clinical trials across the U.S.

"In human drug abusers, many things can cause relapse — exposure or access to drugs, environmental cues that trigger thoughts of the drug, or stress," said Dewey. "If vigabatrin can prevent relapse, it could have a huge impact by helping drug abusers regain control over their lives."

In the current study, rats were first put through a series of conditioning tests that taught them to expect methamphetamine in one chamber of a three-chamber apparatus and saline solution in another chamber. The researchers then allowed the rats to roam freely among the three chambers. If the rats spent the majority of their time in the chamber where they had been given methamphetamine, the scientists knew they had established a "conditioned place preference."

Once this preference was established, the researchers extinguished it by giving the rats saline injections in both chambers, again allowing the animals to have free access to all chambers until the rats had no preference for the previously methamphetamine-associated chamber for at least six consecutive days.

Once extinguished, however, it is possible for a conditioned preference to be reinstated — just as it is possible for a recovered drug addict to relapse. To reinstate the place preference in this experiment, Brookhaven scientists injected the rats with methamphetamine in the neutral chamber. Immediately, rats went to the chamber where they had received methamphetamine and remained there for the duration of the exposure period.

Then, once the reinstatement of a preference was clearly demonstrated, the researchers tested the effectiveness of vigabatrin at blocking it. They pre-treated animals with vigabatrin two-and-a-half hours before giving them another priming dose of methamphetamine followed by free access to all three chambers. When pre-treated with vigabatrin, the rats no longer showed any preference for one chamber over another.

Dewey's group is now conducting studies to examine whether GVG will also block an environmental cue previously shown to produce relapse to drug-seeking behavior.

"These studies have wide implications for addressing the number-one cause of relapse to drug seeking behavior. If we can successfully block drug-induced reinstatement, then our ability to block environmental cue-induced relapse is significantly enhanced," Dewey said.

Collaborators on this study included: Amy DeMarco, now an M.D./Ph.D. student at Stony Brook University, who conducted the research while working in Dewey's lab at Brookhaven last summer and is lead author on the paper; Reema Dalal, Jessica Pai, and Jonathan Brodie of New York University; Stefanie Aquilina of Cornell University; Uma Mullapudi of Dartmouth College; Shiva Kothari of Duke University; Milan Kahanda of Rensselaer Polytechnic Institute; and Crystie Hammel, Courtney Liebling, Vinal Patel, and Wynne Schiffer of Brookhaven Lab. The research was funded by the National Institute on Drug Abuse and the Office of Biological and Environmental Research of DOE's Office of Science.

Using positron emission tomography (PET) to track tracer doses of methamphetamine in humans’ brains, scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory find that the addictive and long-lasting effects of this increasingly prevalent drug can be explained in part by its pharmacokinetics — the rate at which it enters and clears the brain, and its distribution.

This study in 19 healthy, non-drug-abusing volunteers includes a comparison with cocaine and also looked for differences by race. It will appear in the November 1, 2008, issue of Neuroimage.

“Methamphetamine is one of the most addictive and neurotoxic drugs of abuse,” said Brookhaven chemist Joanna Fowler, lead author on the study. “It produces large increases in dopamine, a brain chemical associated with feelings of pleasure and reward — both by increasing dopamine’s release from nerve cells and by blocking its reuptake.”

Studies by Fowler and others have shown that drugs that produce greater elevations in brain dopamine tend to be more addictive. But other factors, including the speed with which a drug enters and clears the brain and its distribution within the brain, can also be important in determining its addictive and toxic potential.

In undertaking this first study of methamphetamine pharmacokinetics, the researchers also wanted to know if there were differences between Caucasians and African Americans. “Reports that the rate of methamphetamine abuse among African Americans is lower than for Caucasians led us to question whether biological or pharmacokinetic differences might explain this difference,” Fowler said.

The scientists measured brain uptake, distribution, and clearance of methamphetamine by injecting 19 normal healthy men (9 Caucasian, 10 African American) with a radioactively tagged form of the drug in “trace” doses too small to have any psychoactive effects. They used PET scanning cameras to monitor the concentration and distribution of the tagged methamphetamine in the subjects’ brains. On the same day, the same subjects were injected with trace doses of cocaine and scanned for comparison. The scientists also used PET to measure the number of dopamine reuptake proteins, known as dopamine transporters, available in each research subject’s brain.

Like cocaine, methamphetamine entered the brain quickly, a finding consistent with both drugs’ highly reinforcing effects. Methamphetamine, however, lingered in the brain significantly longer than cocaine, which cleared quickly. In fact, some brain regions, particularly white matter, still showed signs of tracer methamphetamine at the end of the 90-minute scanning session, by which time all cocaine had been cleared. The distribution of methamphetamine in the brain was remarkably different from that of cocaine. Whereas cocaine was concentrated only in the ‘reward’ center and cleared rapidly, methamphetamine was concentrated all over the brain, where it remained throughout the study.

“This slow clearance of methamphetamine from such widespread brain regions may help explain why the drug has such long-lasting behavioral and neurotoxic effects,” Fowler said. Methamphetamine is known to produce lasting damage not only to dopamine cells but also to other brain regions, including white matter, that are not part of the dopamine network.

Surprisingly, the researchers found significant differences in cocaine pharmacokinetics between African Americans and Caucasians, with the African Americans exhibiting higher uptake of cocaine, a later rise to peak levels, and slower clearance. In contrast, the scientists found no differences in methamphetamine pharmacokinetics between these groups.

“This suggests that variables other than pharmacokinetics and bioavailability account for the lower prevalence of methamphetamine abuse in African Americans,” Fowler said. “The differences observed for cocaine pharmacokinetics are surprising considering there are no differences in cocaine abuse prevalence between these two ethnic groups.” These differences may merit further study, and also suggest the need to match subjects by ethnic group in future studies to avoid interference from this potentially confounding variable.

Another interesting finding was that across all research subjects, the level of dopamine transporters was directly related to the level of methamphetamine taken up by the brain. This finding suggests that transporter proteins somehow play a role in regulating the brain’s uptake of this drug.

This research was funded by the National Institute on Drug Abuse, the National Institute on Alcohol Abuse and Alcoholism Intramural Program, and by the Office of Biological and Environmental Research within DOE’s Office of Science. Brain-imaging studies such as PET are a direct outgrowth of DOE’s long-standing investment in basic research in chemistry, physics, and nuclear medicine. The ongoing neuroimaging research at Brookhaven is a prime example of how DOE’s national laboratories bring together the expertise of chemists, physicists, and medical scientists to address questions of profound significance for society.

When smoked, crystal meth rapidly achieves high concentrations in the brain without the burdens of the intravenous route. Kish reviews the actions of methamphetamine and explains the potential role of dopamine in methamphetamine craving.

The author states that there is no medication approved for the treatment of relapses of methamphetamine addiction, but potential therapeutic agents targeted to dopamine and non-dopamine systems are in clinical testing.

"Research into the pharmacologic treatment of methamphetamine addiction has largely been limited to studies in animals," states Kish. "Although animal studies are essential to the development of new medications, given the public health importance of this worldwide problem and the existence of potential drug targets, it is obvious that the very slow pace of clinical testing of new therapies in methamphetamine addiction needs to be accelerated."

Prevention, treatment, enforcement and harm reduction form the 4 pillars of the York Region's strategy to combat methamphetamine. In their article, Cronkwright, Kirkos and colleagues recognize that criminal behavior is only one element in the production and use of methamphetamine, and they identify elected officials, school boards, the courts, at-risk communities and private industry as key stakeholders in the strategy. 

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Journal Reference:

1. Kish, Stephen J., PhD. Pharmacologic mechanisms of crystal meth. CMAJ, 2008 178: 1679-1682 DOI: 10.1503/cmaj.071675

Young adults who abuse amphetamines may be at greater risk of suffering a heart attack, UT Southwestern Medical Center researchers have found.

In the study, available online in the journal Drug and Alcohol Dependence, researchers examined data from more than 3 million people between 18 and 44 years old hospitalized from 2000 through 2003 in Texas and found a relationship between a diagnosis of amphetamine abuse and heart attack.

Individual case reports have suggested a link between heart attack and amphetamine abuse, but this is believed to be the first epidemiological study of a large group of people on the issue, said Dr. Arthur Westover, assistant professor of psychiatry at UT Southwestern and the study's lead author.

"Most people aren't surprised that methamphetamines and amphetamines are bad for your health," Dr. Westover said. "But we are concerned because heart attacks in the young are rare and can be very debilitating or deadly."

Amphetamines are stimulants that can be used to treat medical conditions such as attention-deficient disorder. They are illegally abused as recreational drugs or performance enhancers.

The researchers note that abuse of methamphetamine, a type of amphetamine often sold illegally, is increasing in most major U.S. cities.

In Texas, the researchers found greater amphetamine abuse in the north and Panhandle regions.

"This paper sounds a warning to amphetamine abusers, alerts emergency department personnel to look for amphetamine abuse in young heart attack patients, and it allows us to focus preventive efforts in geographical areas where the problems are greatest," said Dr. Robert W. Haley, chief of epidemiology at UT Southwestern and senior author of the study. Dr. Haley holds the U.S. Armed Forces Veterans Distinguished Chair for Medical Research, Honoring America's Gulf War Veterans.

"We're also concerned that the number of amphetamine-related heart attacks could be increasing," Dr. Westover said. "We'd rather raise the warning flag now than later. Hopefully, we can decrease the number of people who suffer heart attacks as the result of amphetamine abuse."

Amphetamines may contribute to heart attacks by increasing heart rate and blood pressure and by causing inflammation and artery spasms that limit blood to the heart muscle. More research is needed to determine the exact mechanism of how amphetamines work on the heart, he said.

The current research could help doctors determine the cause of heart attacks in young adults, as well as treatment. Doctors recognizing an amphetamine-caused heart attack might choose not to administer a beta-blocker medication, a common treatment for heart attack, because it could interact with methamphetamine to make the heart attack worse.

The results could have broad implications in the general population, Dr. Westover said. Texas ranks 27th among all states in use of methamphetamine among 18- to 25-year-old adults, according to a 2006 government report.

"We're talking about a state that is near the middle of prevalence of methamphetamine use in the United States, so it's possible that the number of heart attacks in young adults in other states with a much higher prevalence of amphetamine abuse may be higher as well," said Dr. Westover, who is a National Institutes of Health Multidisciplinary Clinical Research Scholar at UT Southwestern.

Dr. Paul Nakonezny, assistant professor of clinical sciences and psychiatry at UT Southwestern, was also involved in the study.

The work was supported by a North and Central Texas Clinical and Translational Science Initiative grant from the National Center for Research Resources, a component of the National Institutes of Health.

 Studies have suggested that infants exposed to methamphetamines while in the womb can suffer irreversible brain damage, although the exact effects of these drugs during pregnancy have been hard to pinpoint due to many other negative behaviors that often occur in meth users.

Now, using a guinea pig model that can assess neural changes in offspring born to mothers given methamphetamine during an otherwise normal pregnancy, Dr. Sanika Samuel Chirwa provides new evidence for the cognitive damage of these drugs.

In preliminary studies, Chirwa and colleagues found that guinea pig pups born to mothers that had received 1 mg/day of methamphetamine during pregnancy exhibit an impaired ability to distinguish novel objects from items they had seen before. This lack of recognition correlated with changes in the brain region, the hippocampus, associated with memory formation.

Repeatedly stimulating the mouse brain with methamphetamine depresses important areas of the brain, and those changes can only be undone by re-introducing the drug, according to research at the University of Washington and other institutions. The study, which appears in the April 10 issue of the journal Neuron, provides one of the most in-depth views of the mechanisms of methamphetamine addiction, and suggests that withdrawal from the drug may not undo the changes the stimulant can cause in the brain.

The researchers set out to determine what sort of changes happen in the brain because of repeated use of the stimulant methamphetamine, and to better understand addiction-related behaviors like drug craving and relapse. Methamphetamine, also known as simply meth, is one of the most popular illegal drugs in the United States, and abuse of the drug can cause severe addiction.

Scientists have believed that abuse of drugs like meth can cause changes to the neurons in the brain and the synapses and terminals that control transmission of information in the brain. In this project, researchers focused on the mouse brain, and how it was affected by methamphetamine over 10 days, which is the mouse equivalent of chronic use in humans.

They found that the long administration and withdrawal of the drug depressed the neural terminals controlling the flow of signals between two areas of the brain, the cortex and striatum. Even a long period of withdrawal — the equivalent of years in humans — did not return the terminals to normal activity level. Re-introducing the drug, however, reversed the changes in the brain.

The areas affected by the drug are called pre-synaptic terminals, and are related to the flow of information from the cortex to the striatum. When a person sees something new in their environment, the scientists explained, she focuses attention on that item. At the neuron level, that process stimulates the release of dopamine, a chemical involved in transmitting signals in the brain. As the person sees the new item over and over again, the dopamine response drops, and synapses in the brain adapt to the no-longer-new item.

What happens with methamphetamine use is that the drug makes the nervous system release dopamine, which helps a user focus a lot of attention on a particular goal. Scientists believe that meth allows dopamine in the striatum to filter information coming from the cortex through the pre-synaptic terminals. The filtering of some of the terminals would help someone ignore other things and focus on that one goal or task.

After chronic use of methamphetamine, the filtering process eventually becomes a permanent depression in the activity of those terminals in the brain, the scientists found. And the only thing that can help the pre-synaptic terminals recover in mice, they found, was re-administering the drug.

"What we found is that the repeated use of methamphetamine causes adaptations in the brain, and that only re-introducing the drug can reverse that," said Dr. Nigel Bamford, UW assistant professor of neurology and pediatrics and a physician at Seattle Children's Hospital. "We think these changes in the brain may account for at least some of the physiological components of meth addiction."

If the mechanism turns out to be similar in people, Bamford said, this could have big effects on the treatment and management of methamphetamine addiction. One treatment for drug addiction is to give people smaller and smaller amounts of the drug to wean them from it and reduce the effects of withdrawal. Unfortunately, that method would not affect the adaptation of the neural terminals in the brain.

"Now that we have some understanding of the mechanism through which meth addiction occurs, we may be able to develop other approaches to treating addiction," explained Bamford. "We might be able to target some of the chemical receptors in the brain to reset the system and get rid of this depressed state in the pre-synaptic terminals."

Though scientists believe that other stimulants, like methylphenidate, may have similar effects on the brain, they caution against applying these findings to other situations. These synaptic changes may not occur in patients with underlying conditions that require treatment with stimulants, the scientists said.

This research was supported by several grants, including two from the National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health. It was also supported by Seattle Children's Hospital and the Center for Human Development and Disability at the UW. The project included researchers with Columbia University, the New York State Psychiatric Institute, and the University of California at Los Angeles.

New findings that one in 20 North Carolina men who have sex with men (MSM) reported using crystal methamphetamine during the previous month suggests increased risk for spreading HIV and other sexually transmitted diseases (STD), according to researchers from Wake Forest University School of Medicine and colleagues.

The rate of methamphetamine use among 1,189 MSM was 30 times higher than levels reported in the general U.S. population over the same period. Methampehtamine, or "meth," is a highly addictive stimulant that has been found to impair judgment, decrease inhibition, increase impulsivity and enhance sexual sensitivity — which can all increase the potential for transmitting HIV.

The study's authors found that participants who reported using methamphetamines were more likely to report inconsistent condom use during anal sex within the past three months, a history of STD infection, being HIV-positive and using medications designed to treat erectile dysfunction.

"Until now, there has been little data on meth use in the Southeast," said lead author Scott D. Rhodes, Ph.D. M.P.H., associate professor in the Department of Social Sciences and Health Policy. "Our findings, including that meth users were more likely to be HIV-positive, suggest that prevention, intervention and treatment efforts are urgently needed."

Rhodes noted that some of the men reported having sex with both men and women, which means the risk of HIV extends to both sexes.

The study's results will be published on Aug. 20 in AIDS Patient Care and STDs, a leading AIDS journal that provides the latest research for clinicians and researchers. It is among the first to document meth use among MSM in the South, which carries a disproportionate HIV, AIDS, and STD burden, with 46 percent of newly identified cases.

"The findings underscore the need for further research and intervention," said Rhodes. "The HIV/AIDS epidemic is clearly not over. We must develop innovative intervention approaches designed to reach communities at highest risk. Men who have sex with men, whether or not they identify themselves as gay, who use drugs like methamphetamines are clearly at higher risk. Yet currently nothing is being done in the Southeast."

Participants were recruited in 2005 in five gay bars and in five geographically defined internet chat rooms in central North Carolina (primarily rural/suburban areas) and were asked to complete a brief assessment of drug use and other risk behaviors. Of the 1,189 MSM, two-thirds self-identified as black or other minorities, and 25 percent as bisexual. The mean age was 29 years.

In addition to being more inclined to risky sexual behaviors, the study participants who said they used methamphetamines were also more likely to report having higher education and health insurance coverage.

"Because users of methamphetamines were more likely to have higher educational levels and report having health insurance, we must change the way we think about meth users and develop sophisticated prevention strategies that are appropriate for these types of users," noted Rhodes. "In addition, the link between meth use and the use of drugs for sexual dysfunction among a young population deserves attention. Meth use in combination with one of these medications may be having an even more profound impact on the HIV and STD disease epidemics in the South."

Rhodes is also affiliated with the Maya Angelou Research Center on Minority Health at Wake Forest. In 2006, Rhodes won the New Investigator Award in Clinical Sciences at Wake Forest.

The study's co-authors include Emily Knipper and Aimee M. Wilkin, M.D., M.P.H., both with Wake Forest, Kenneth C. Hergenrather, Ph.D., M.S.Ed., M.R.C., of George Washington University, Leland J. Yee, Ph.D., M.P.H., of the University of Pittsburgh, and Morrow R. Omli, M.A.Ed., of the University of Florida.