Category: Illegal Drugs

An international team of immunologists studying the effects of cannabis have discovered how smoking marijuana can trigger a suppression of the body's immune functions. The research, published in the European Journal of Immunology, reveals why cannabis users are more susceptible to certain types of cancers and infections.

The team, led by Dr Prakash Nagarkatti from the University of South Carolina, focused their research on cannabinoids, a group of compounds found inside the cannabis plant, including THC (delta-9 tetahydrocannabinol) which is already used for medical purposes such as pain relief.

"Cannabis is one of the most widely used drugs of abuse worldwide and it is already believed to suppress immune functions making the user more susceptible to infections and some types of cancer," said Dr Nagarkatti. "We believe the key to this suppression is a unique type of immune cell, which has only recently been identified by immunologists, called myeloid-derived suppressor cells, MDSCs."

While most immune cells fight against infections and cancers to protect the host, MDSCs actively suppress the immune system. The presence of these cells is known to increase in cancer patients and it is believed that MDSCs may suppress the immune system against cancer therapy, actually promoting cancer growth.

Dr Nagarkatti's team demonstrated that cannabinoids can trigger a massive number of MDSCs through activation of cannabinoid receptors. This research reveals, for the first time, that marijuana cannabinoids may suppress the immune system by activating these unique cells.

"These results raise interesting questions on whether increased susceptibility to certain types of cancers or infections caused from smoking marijuana results from induction of MDSCs," said Nagarkatti. "MDSCs seem to be unique and important cells that may be triggered by inappropriate production of certain growth factors by cancer cells or other chemical agents such as cannabinoids, which lead to a suppression of the immune system's response."

In a related study, also published in the European journal of Immunology, Dr Christian Vosshenrich from the Institut Pasteur in Paris, reveals that when cancer cells grow they produce a molecule called interleukin-1 β (IL-1β), which also triggers MDSCs. This study identifies how MDSCs produced during cancer growth also weaken the ability of immune cells to kill cancer cells.

"Marijuana cannabinoids present us with a double edged sword," concluded Dr Nagarkatti. "On one hand, due to their immunosuppressive nature, they can cause increased susceptibility to cancer and infections. However, further research of these compounds could provide opportunities to treat a large number of clinical disorders where suppressing the immune response is actually beneficial."

---

Journal Reference:

1. Venkatesh L. Hegde, Mitzi Nagarkatti and Prakash S. Nagarkatti. Cannabinoid receptor activation leads to massive mobilization of myeloid-derived suppressor cells with potent immunosuppressive properties. European Journal of Immunology, 2010; 40 (12): 3358-3371 DOI: 10.1002/eji.201040667

Many mental health disorders, such as autism and schizophrenia, produce changes in social behavior or interactions. The frequency and/or severity of these disorders is substantially greater in boys than girls, but the biological basis for this difference between the two sexes is unknown.

Researchers at the University of Maryland School of Medicine have discovered differences in the development of the amygdala region of the brain — which is critical to the expression of emotional and social behaviors — in animal models that may help to explain why some mental health disorders are more prevalent among boys. They also found a surprising variable — a difference between males and females in the level of endocannabinoid, a natural substance in the brain that affected their behavior, specifically how they played.

The study results have been published online this month in the Proceedings of the National Academy of Sciences.

Margaret M. McCarthy, Ph.D., the senior author and a professor of physiology and psychiatry at the University of Maryland School of Medicine, says, "Our findings help us to better understand the differences in brain development between males and females that may eventually provide the biologic basis for why some mental health conditions are more prevalent in males. We need to determine if these neural differences in the developing brain that we've seen in rats may cause similar behavioral effects in human babies."

Dr. McCarthy and her colleagues found that female rats have about 30 to 50 percent more glial cells in the amygdala region of the temporal lobe of the brain than their male litter mates. They also found that the females had lower amounts of endocannabinoids, which have been dubbed the brain's own marijuana because they activate cannabinoid receptors that are also stimulated by THC, the main psychoactive ingredient of cannabis.

Researchers also found that the female rats also played 30 to 40 percent less than male rats. However, when these newborn female rats were given a cannabis-like compound to stimulate their natural endocannabinoid system, their glial cell production decreased and they displayed increased play behavior later as juveniles. In fact, the level of play exhibited by females treated with a cannabis-like compound was very similar to levels in male rats, the researchers found. Yet exposure to this cannabis-like compound did not appear to have any discernible effect on newborn male rats.

Dr. McCarthy, who is also associate dean for Graduate Studies and interim chair of the Department of Pharmacology & Experimental Therapeutics, notes, "We have never before seen a sex difference such as this in the developing brain involving cell proliferation in females that is regulated by endocannabinoids."

E. Albert Reece, M.D., Ph.D., M.B.A., vice president of medical affairs at the University of Maryland and dean of the University of Maryland School of Medicine, says, "The results of this study provide important clues to brain differences between males and females and may increase our knowledge about how these differences may affect both normal and aberrant brain development, thereby enhancing our understanding of many mental health disorders."

---

Journal Reference:

1. Desiree L. Krebs-Kraft, Matthew N. Hill, Cecilia J. Hillard, and Margaret M. Mccarthy. Sex difference in cell proliferation in developing rat amygdala mediated by endocannabinoids has implications for social behavior. PNAS, November 8, 2010 DOI: 10.1073/pnas.1005003107

New research shows that people who start using marijuana at a young age and those who use the greatest amount of marijuana may be the most cognitively impaired.

The research was presented at Neuroscience 2010, the annual meeting of the Society for Neuroscience, held in San Diego.

Marijuana users show deficits in the ability to switch behavioral responses according to the context of a situation, also known as cognitive flexibility. The new study, directed by Staci Gruber, PhD, at McLean Hospital and Harvard Medical School, compared people's performance on the Wisconsin Card Sorting Task, a test of cognitive flexibility. During the task, people are shown four shown cards that differ in color, symbol, and value. Based on the rules they glean from these displayed cards, they must then sort a deck of cards. The participants are not told what the rules are — only whether their sorting attempt is correct or incorrect. During the test, the researchers change the rules without warning, and participants must adjust accordingly. How a participant responds is a strong indicator of cognitive flexibility.

The researchers found that habitual marijuana users made repeated errors despite feedback that they were wrong. Marijuana users also had more difficulty maintaining a set of rules, suggesting an inability to maintain focus. Those participants who began using marijuana before the age of 16 and those who used the most marijuana showed the greatest impairment.

"Our results provide further evidence that marijuana use has a direct effect on executive function, and that both age of onset and magnitude of marijuana use can significantly influence cognitive processing," said Gruber. "Given the prevalence of marijuana use in the United States, these findings underscore the importance of establishing effective strategies to decrease marijuana use, especially in younger populations," she said.

Research was supported by the National Institute on Drug Abuse.

Abuse of prescription pain relievers, such as morphine, during adolescence alters the brains of future offspring, a new animal study found.

The research was presented at Neuroscience 2010, the annual meeting of the Society for Neuroscience, held in San Diego.

"Abuse of prescription pain relievers among adolescents — girls as well as boys — is a growing concern," said Elizabeth Byrnes, PhD, of Tufts University. "Unfortunately, the long-term consequences of female adolescent drug use, particularly on future children, are unknown. Our findings suggest that a mother's history of drug use may have a significant impact on her children and grandchildren, even if the woman was not using drugs at the time she got pregnant."

For this study, female rats were given morphine for 10 days during adolescence. The doses were similar to what an abuser of prescription narcotics might use. After a drug-free period, the females were mated with healthy males, and the first and second generation offspring were subsequently studied when they reached adulthood.

First generation male adult offspring demonstrated decreased sensitivity to the drug quinpirole, a chemical that mimics the reward chemical dopamine in the brain. They also found this same effect in the second generation male offspring.

Disruption of dopamine is associated with addiction and psychiatric disorders. "Our model could be used to help determine how substance abuse and other reward-related disorders are passed down through several generations," said Byrnes. "We are currently examining changes in the expression of particular genes in both the mother and her offspring to determine how these effects are transmitted," she said.

Research was supported by the National Institute on Drug Abuse.

A new system that ranks drugs on the basis of harm caused to both the user and others places alcohol as the most harmful drug, above heroin and crack. The scale, developed by drug experts led by Professor David Nutt of Imperial College London, is published online in The Lancet.

Drugs including alcohol and tobacco products are a major cause of harms to individuals and society. To provide better guidance to policy makers in health, policing, and social care, the harms that drugs cause need to be properly assessed. This task is not easy because of the wide range of ways in which drugs can cause harm, the researchers say.

When Professor Nutt and colleagues attempted this assessment previously in 2007, they engaged experts to score each drug according to nine criteria of harm, ranging from the intrinsic harms of the drugs to social and healthcare costs. This analysis provoked major interest and public debate, although it raised concerns about the choice of the nine criteria and the absence of any differential weighting of them.

To rectify these drawbacks, the authors undertook a review of drug harms with the multicriteria decision analysis (MCDA) approach. MCDA technology has been used successfully to lend support to decision makers facing complex issues characterised by many, conflicting objectives, such as policies for disposal of nuclear waste.

Multicriteria decision analysis

The new analysis uses nine criteria that relate to the harms that a drug produces in the individual and seven to the harms to others both in the UK and overseas. These harms are clustered into five subgroups representing physical, psychological, and social harms.

Drugs were scored with points out of 100, with 100 assigned to the most harmful drug on a specific criterion. Zero indicated no harm. Explaining their model, the authors say: "In scaling of the drugs, care is needed to ensure that each successive point on the scale represents equal increments of harm. Thus, if a drug is scored at 50, then it should be half as harmful as the drug that scored 100." A zero means no harm is caused.

The criteria are weighted according to a judgement of their relative importance. "The issue of the weightings is crucial since they affect the overall scores," the authors say. "The weighting process is necessarily based on judgement, so it is best done by a group of experts working to consensus."

The nine categories in harm to self are drug-specific mortality, drug-related mortality, drug-specific damage, drug-related damage, dependence, drug-specific impairment of mental function, drug-related impairment of mental functioning, loss of tangibles, loss of relationships, and injury. The harm to others categories are crime, environmental damage, family conflict, international damage, economic cost, and decline in community cohesion.

Overall, MCDA modelling showed alcohol was the most harmful drug (overall harm score 72), with heroin (55) and crack (54) in second and third places. Heroin, crack, and crystal meth were the most harmful drugs to the individual, whereas alcohol, heroin, and crack were the most harmful to others. The other drugs assessed followed in this order in terms of overall harm: Crystal meth (33), cocaine (27), tobacco (26), amphetamine/speed (23), cannabis (20), GHB (18), benzodiazepines (eg valium) (15), ketamine (also 15), methadone (14), mephedrone (13), butane (10), khat (9), ecstacy (9), anabolic steroids (9), LSD (7), buprenorphine (6), mushrooms (5).

Thus the new ISCD MCDA modelling showed that as well as being the most harmful drug overall, alcohol is almost three times as harmful as cocaine or tobacco. It also showed that alcohol is more than five times more harmful than mephedrone, which was recently a so-called legal high in the UK before it was made a class B controlled drug in April 2010. Ecstasy, which has had much harm-related media attention over the past two decades, is only one eighth as harmful as alcohol in this new analysis.

Implications for drug policy

The authors say that their work correlates with both the previous analysis by Nutt and colleagues and that of other such as the Dutch addiction medicine expert group. However, there is almost no relation between the results and the current UK drug classification system based on the UK Misuse of Drugs Act (1971).

Professor Nutt, from the Department of Medicine at Imperial College London, says: "What a new classification system might look like would depend on what set of harms — to self or others — you are trying to reduce. But if you take overall harm, then alcohol, heroin and crack are clearly more harmful than all others so perhaps drugs with a score of 40 or more could be class A; 39 to 20 class B; 19-10 class C and 10 or under class D."

The authors say the MCDA process provides a powerful means to deal with complex issues that drug misuse represents.

They conclude: "Our findings lend support to previous work in the UK and the Netherlands, confirming that the present drug classification systems have little relation to the evidence of harm. They also accord with the conclusions of previous expert reports that aggressively targeting alcohol harms is a valid and necessary public health strategy."

---

Journal References:

1. David J Nutt, Leslie A King, Lawrence D Phillips. Drug harms in the UK: a multicriteria decision analysis. The Lancet, 2010; DOI: 10.1016/S0140-6736(10)61462-6
2. Jan van Amsterdam, Wim van den Brink. Ranking of drugs: a more balanced risk-assessment. The Lancet, 2010; DOI: 10.1016/S0140-6736(10)62000-4

Alcohol, to an adolescent, is often seen as a rite of passage. Many teenagers view alcohol (as well as other drugs) as a gateway to adulthood, but are often blissfully unaware of the damage that it can cause to their bodies. A new study of the effects of excessive alcohol and other drugs in adolescents has shown that both alcohol and marijuana overuse can cause serious detrimental effects on the development of the teenage mind.

Results will be published in the January 2011 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.

"The effects of alcohol and marijuana use on cognition in adults have been researched for decades but are only now beginning to receive attention in adolescents," said Robert J. Thoma, a Clinical Neuropsychologist and Associate Professor of Psychiatry at the University of New Mexico School of Medicine. "Both animal models and observational studies in humans suggest that binge drinking during adolescence alters normal developmental processes in a way that negatively impacts learning and social adjustment into adulthood."

Thoma added that during adolescent brain development, the frontal lobe plays an important role in the development of judgment, social skills, and decision-making. "Heavy drinking may disrupt normal neurodevelopmental processes that hone and sharpen attention and executive function during adolescence in that alcohol may selectively target the frontal lobes."

The researchers assessed 19 adolescents that have been diagnosed with substance abuse/dependence, and 14 individuals that have a family history of substance abuse with no history of personal usage. This, in addition to the 15 individuals in the control group, helped the researchers analyze the neurophysiological changes associated with substance abuse.

The researchers discovered, after a battery of psychological tests on the experimental groups, that both frequent alcohol and marijuana use significantly affected the adolescent mind. As drinking intensity increased, individuals demonstrated a significant decrease in attention and executive function (which is involved with planning and selecting appropriate actions based on a selective stimulus). Meanwhile, increased marijuana use in both groups was also heavily associated with a decrease in memory performance.

"It could be that intense drinking during adolescence leads to delays or incomplete development of frontal brain regions, which in turn leads to problems with attention and executive functioning," said Susan F. Tapert, a Professor of Psychiatry at VA San Diego Healthcare System and the University of California San Diego.

Tapert also noted that if the adolescents were to abstain from alcohol, it may help in recovering the lost function in brain cells, which is a well-established treatment for alcohol-induced brain trauma in adults.

Thoma agreed. "Recovery of function with cessation of drinking is a well-established finding in adults," he said. "And there is reason to believe that the same would hold in youth, who tend to be resilient. If decrements in attention and executive function are indeed caused by alcohol, it is likely that these effects would abate with abstinence from or at least reduction of drinking."

But, this research is only the first step in helping children diagnosed with substance abuse disorders. Thoma and his team plan to continue their research and determine if the effects on the brain are dose-dependent and if modest alcohol use would therefore require intervention.

"We also hope to design studies to test complex models concerning how adolescent substance abuse develops and either persists or abates over time. Development of a substance use disorder involves a complex interplay of cognitive, behavioral, and genetic factors that science is only beginning to pinpoint."

---

Journal Reference:

1. Robert J. Thoma, Mollie A. Monnig, Per A. Lysne, David A. Ruhl, Jessica A. Pommy, Michael Bogenschutz, J. Scott Tonigan and Ronald A. Yeo. Adolescent Substance Abuse: The Effects of Alcohol and Marijuana on Neuropsychological Performance. Alcoholism: Clinical & Experimental Research, 2010; DOI: 10.1111/j.1530-0277.2010.01320.x

 A newly discovered molecular mechanism helps control the amount and effectiveness of a substance that mimics an active ingredient in marijuana, but that is produced by the body's own nerve cells.

The results were reported in the latest Nature Neuroscience. The lead author on the study is William R. Marrs of the Neurobiology and Behavior program at the University of Washington (UW). The senior author is Dr. Nephi Stella, UW professor of pharmacology and psychiatry.

In previous papers, Stella and other scientists have noted that the body manufactures several cell signals that mimic the actions of marijuana-derived chemicals These signals are called endocannabinoids, a Latin-derived name for marijuana-like (cannabis) constituents created by the body's own cells (endo).

Marrs, Stella and their research team study endocannabinoids, their receptors on cells, and the cell functions controlled by these signals.

They hope their future work encourages the design of therapies to modulate these molecular communications. Specifically targeted treatments, for example, might give cancer and AIDS patients the same medicinal benefits as marijuana without its mind-altering properties.

Because cannabinoid signaling systems are common throughout the body and affect a variety of functions, therapies aimed at these systems might be more wide-ranging than simply a better substitute for medicinal marijuana. Stella is especially interest in the potential for helping people with conditions for which even symptomatic treatment is limited or non-existent, such as multiple sclerosis, brain tumors, Huntington's disease and other autoimmune or neurological disorders.

Earlier Stella's group discovered a key endocannabinoid, called 2-AG, that carries a type of messaging between brain cells. 2-AG is also implicated in brain cell migration and brain tissue inflammation. It does this by activating one type of cannabinoid receptor on neurons, and another type of cannabinoid receptor on microglia, the tiny cells that clean up debris, like damaged nerve cells and plaque, in the brain and spinal cord. As the brain's first line of defense against infection, microglia are attune to the most subtle clues suggesting an attack.

Stella's team further investigated 2-AG nerve cell signaling in the study just published in Nature Neuroscience. They looked at an enzyme called ABHD6, newly identified by other scientists using advanced protein profiling technology, also known as proteomics. ABHD6 is present in nerve cells in the brain.

Stella's team observed that this enzyme degrades the 2-AG nerve signaling substance by splitting it with water. This happens near the cell receptor for the 2-AG signal.

Breaking apart 2-AG reduced its accumulation and decreased its ability to prod other cells to action. In this case, the broken down 2-AG was less effective in stimulating the microglia — the brain defenders — to get moving.

The results provided by their study, the authors said, suggest that the enzyme ABDH6 "is a bona fide member of the endocannabinoid signaling system."

"The enzymatic steps that control the production and inactivation of endocannabinoids constitute promising molecular targets for indirectly modulating the activity of cannabinoid receptors," the authors noted. Designing treatments that manage the production and inactivation of important enzymes like ABHD6 could thereby control such conditions as brain inflammation or overactive brain signals. Other enzymes are involved in controlling the accumulation of different endocannabinoids.

Each of these enzymes, the researchers pointed out, provides a unique therapeutic opportunity. Inhibiting distinct enzymes would allow for the fine-tuned direction of endocannabinoid signaling. For example, blocking a specific enzyme to heighten a certain signal might ameliorate pain and also act as anti-anxiety and antidepressant therapy, the authors explained. Drugs that reduce the activity of the ABDH6 enzyme might prevent brain damage from an overactive response to a virus.

The study was supported by grants from the National Institute on Drug Abuse and the National Institute of General Medical Sciences, both part of the National Institutes of Health.

In addition to Marrs and Stella, other researchers on the study are Jacqueline L. Blankman, Jessica P. Alexander, Jonathan Z. Long, Weiwei Li, and Benjamin F. Cravatt, all of Scripps Research Institute; Eric A. Horne, Yi Hsing Lin, Jonathan Coy, and Cong Xu, all of the UW Department of Pharmacology; Aurore Thomazeau, Mathieu LaFourcade and Olivier J. Manzoni, all of INSERM, Bordeaux, France; Agnes L. Bodor of the UW Department of Otolaryngology; Giulio G. Muccioli of the Louvain Drug Research Institute, Bruxelles, Belgium; Sherry Shu-Jung Hu and Ken Mackie, of Indiana University; Grace Woodruff of the UW Neurobiology Undergraduate Program; Susan Fung of the UW Neurobiology and Behavior Graduate Program, and Thomas Moller of the UW Department of Neurology.

---

Journal Reference:

1. William R Marrs, Jacqueline L Blankman, Eric A Horne, Aurore Thomazeau, Yi Hsing Lin, Jonathan Coy, Agnes L Bodor, Giulio G Muccioli, Sherry Shu-Jung Hu, Grace Woodruff, Susan Fung, Mathieu Lafourcade, Jessica P Alexander, Jonathan Z Long, Weiwei Li, Cong Xu, Thomas Möller, Ken Mackie, Olivier J Manzoni, Benjamin F Cravatt, Nephi Stella. The serine hydrolase ABHD6 controls the accumulation and efficacy of 2-AG at cannabinoid receptors. Nature Neuroscience, 2010; 13 (8): 951 DOI: 10.1038/nn.2601

— A new compound similar to the active component of marijuana (cannabis) might provide effective pain relief without the mental and physical side effects of cannabis, according to a study in the July issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS).

The synthetic cannabinoid (cannabis-related) compound, called MDA19, seems to avoid side effects by acting mainly on one specific subtype of the cannabinoid receptor. "MDA19 has the potential for alleviating neuropathic pain without producing adverse effects in the central nervous system," according to the study by Dr Mohamed Naguib of The University of Texas M.D. Anderson Cancer Center.

MDA19 Works on a Single Cannabinoid Receptor

The researchers performed a series of experiments to analyze the pharmacology and effects of the synthetic cannabinoid MDA19. There are two subtypes of the cannabinoid chemical receptor: CB1, found mainly in the brain; and CB2, found mainly in the peripheral immune system. Dr. Naguib's group has been doing research to see if the cannabinoid receptors — particularly CB2 — can be a useful target for new drugs to treat neuropathic pain. Neuropathic pain is a difficult-to-treat type of pain caused by nerve damage, common in patients with trauma, diabetes, and other conditions.

MDA19 was designed to have a much stronger effect on the CB2 receptor than on the CB1 receptor. In humans, MDA19 showed four times greater activity on the CB2 receptor than on the CB1 receptor. In rats, the difference was even greater. The experiments also showed that MDA19 had "protean" effects, so-called after the shape-shifting Greek sea god Proteus — under different conditions, it could either block or activate the cannabinoid receptors.

In rats, treatment with MDA19 effectively reduced specific types of neuropathic pain, with greater effects at higher doses. At the same time, it did not seem to cause any of the behavioral effects associated with marijuana.

Potential to Develop Effective Pain Drugs that Avoid Side Effects The "functional selectivity" of MDA19 — the fact that it acts mainly on the CB2 receptor and has a range of effects under differing conditions — could have important implications for drug development. "[W]ith functionally selective drugs, it would be possible to separate the desired from the undesired effects of a single molecule through a single receptor," Dr. Naguib and colleagues write.

This means that MDA19 could be a promising step toward developing medications that have the pain-reducing effect of cannabinoids while avoiding the mental and physical side effects of marijuana itself. However, more research will be needed before MDA19 or other agents that act on the CB2 receptor are ready for testing in humans.

"These elegant studies by Professor Naguib demonstrate remarkable analgesic properties for this synthetic cannabinoid," comments Dr. Steven L. Shafer of Columbia University, Editor-in-Chief of Anesthesia &Analgesia. "The studies suggest a novel mechanism for this protean agonist. Although preliminary, these studies suggest that synthetic cannabinoids may be significant step forward for patients suffering from neuropathic pain."

---

Journal Reference:

1. Jijun J. Xu et al. Pharmacological Characterization of a Novel Cannabinoid Ligand, MDA19, for Treatment of Neuropathic Pain. Anesthesia & Analgesia, July 2010 vol. 111 no. 1 99-109

 A Nova Southeastern University study recently presented at a national conference found that 80 percent of poker players around the world reported using drugs and other substances to enhance their performance in poker.

Poker players are using drugs such as marijuana, cocaine, amphetamines, Valium, and other prescription medications, as well as substances including caffeine, energy drinks and guarana to get an edge over their opponents.

"The use these substances could allow poker players to stay awake longer, as well as focus and concentrate better, which would be a competitive advantage," said Kevin Clauson, Pharm.D., an associate professor at NSU's College of Pharmacy, who was the principle investigator in the study. "Stamina is important for any poker player because tournament poker and cash games can go on for many hours."

Using these substances can be harmful for poker players, Clauson said. Depending on the type of substance, he pointed out; there will likely be short-term and long-term side effects.

The NSU researchers initially interviewed players in Las Vegas during the World Series of Poker and then surveyed players online from across the globe, including North America, Europe, and Asia, with the majority of respondents coming from the US and Canada.

Respondents included professional poker players, semi-pro, amateur, and recreational players. Regardless of one's status, an overwhelming majority of poker involves some amount of money, Clauson said. The players surveyed played poker — largely no-limit Texas hold' em — — both in person and on the Internet. Most were males in their mid-20s.

About 73 percent of the respondents said they used drugs and other substances to focus and concentrate better. The rest used these products to calm their nerves, stay awake, and improve memory.

The results suggest that the use of substances to improve poker performance is widespread, especially at higher stakes, Clauson said. "Most people we surveyed are using some kind of a boost in order to play one of the most popular games in the world," he said.

To view the study highlights, please visit http://www.slideshare.net/kclauson/use-of-cognitive-and-performance-enhancing-medications-in-poker-players