Category: Illegal Drugs

Nearly a quarter of college women try smoking tobacco with a hookah, or water pipe, for the first time during their freshman year, according to new research from The Miriam Hospital's Center for Behavioral and Preventive Medicine.

The study, published online by Psychology of Addictive Behaviors, suggests a possible link to alcohol and marijuana use. Researchers found the more alcohol women consumed, the more likely they were to experiment with hookah smoking, while women who used marijuana engaged in hookah smoking more frequently than their peers.

They say the findings are troubling since hookah smoking rates have increased dramatically among young adults over the last two decades, with some studies putting it on par with cigarette smoking. Many college students also mistakenly believe hookah smoking is safer than cigarettes, even though hookah use has been linked to many of the same diseases caused by cigarette smoking, including lung cancer, respiratory illness and periodontal disease.

"The popularity and social nature of hookah smoking, combined with the fact that college freshmen are more likely to experiment with risky behavior, could set the stage for a potential public health issue, given what we know about the health risks of hookah smoking," said lead author Robyn L. Fielder, M.S., a research intern at The Miriam Hospital's Centers for Behavioral and Preventive Medicine.

Originating in ancient Persia and India, hookah smoking is a highly social activity during which users smoke tobacco filtered through a water pipe, according to the American Lung Association. The tobacco mixtures used in the hookahs vary in composition, with some having flavorings and additives, such as candy and fruit flavors, that help disguise the harshness of the smoke. Hookah smokers are exposed to higher doses of nicotine compared to cigarettes, as well as carbon monoxide and a very high volume of smoke, which contains toxic and cancer-causing smoke particles.

In the study, 483 first-year female college students completed an initial survey about their precollege hookah use, followed by 12 monthly online surveys about their experience with hookah smoking. Of the 343 participants who did not report precollege hookah use, 23 percent (79 students) tried hookah tobacco smoking during their first year of college.

An analysis revealed alcohol consumption predicted the likelihood of hookah use, while marijuana use and certain personality styles, such as a higher level of impulsivity and a strong tendency to compare oneself to others, predicted frequency of use.

Fielder says the findings corroborate prior research showing strong correlations between hookah and other substance use, but their research is the first to show that alcohol and marijuana use are prospectively related to hookah initiation.

"Youth tend to overestimate the extent to which their peers use substances, and because it's important to fit in with one's peers, this can lead to greater risk-taking," said Fielder. "Our research suggests prevention and intervention efforts should jointly target all substance use, including hookah, alcohol, marijuana and cigarettes, to optimize the public health impact."

The study was funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA). Co-authors include Michael P. Carey, Ph.D., director of The Miriam Hospital's Centers for Behavioral and Preventive Medicine, and Kate B. Carey, Ph.D., of Brown University.

Robyn L. Fielder, M.S., is completing a research placement at The Miriam Hospital (a member hospital of the Lifespan health system in Rhode Island) as part of her clinical psychology internship at The Warren Alpert Medical School of Brown University.

This grant is supported by the National Institute on Alcohol Abuse and Alcoholism under award number R21-AA018257. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

— While marijuana use by teens has been increasing since 2005, an analysis of data from 1993 through 2009 by economists at three universities has found no evidence to link the legalization of medical marijuana to increased use of the drug among high school students.

"There is anecdotal evidence that medical marijuana is finding its way into the hands of teenagers, but there's no statistical evidence that legalization increases the probability of use," said Daniel I. Rees, a professor of economics at the University of Colorado Denver .

Rees co-authored the study with Benjamin Hansen, assistant professor of economics at the University of Oregon and D. Mark Anderson, assistant professor of economics at Montana State University.

They examined the relationship between the legalization of medical marijuana and marijuana consumption using nationally representative data on high school students from the Youth Risky Behavior Survey (YRBS) for the years 1993 through 2009, a period when 13 states, including Alaska, California, Colorado, Hawaii, Maine, Nevada, Oregon and Washington, legalized medical marijuana. Seventeen states and the District of Columbia now have such laws with legislation pending in seven others.

"This result is important given that the federal government has recently intensified its efforts to close medical marijuana dispensaries," said Hansen, who studies risky behaviors of adolescents and adults. "In fact, the data often showed a negative relationship between legalization and marijuana use."

Federal officials, including the Director of the Office of National Drug Control Policy, argue that the legalization of medical marijuana has contributed to the recent increase in marijuana use among teens in the United States and have targeted dispensaries operating within 1,000 feet of schools, parks and playgrounds.

According to the 2011 report "Monitoring the Future National Results on Adolescent Drug Use," prepared annually by the University of Michigan Institute for Social Research, marijuana use by 10th and 12th graders has risen in the last three years, with roughly one in 15 high school seniors smoking marijuana daily or near-daily. The report, cited in the economists' study, surveyed 46,700 students in the eighth, 10th and 12th grades, in 400 secondary schools.

The new study "Medical Marijuana Laws and Teen Marijuana Use" currently is a non-peer-reviewed working paper made available by the Institute for the Study of Labor (IZA), a private, non-profit independent research institute based in Bonn, Germany, that conducts internationally oriented labor market research.

Researchers examined the relationship between legalization and a variety of outcomes including: marijuana use at school, whether the respondent was offered drugs on school property, alcohol use, and cocaine use. Their results provided no evidence that legalization led to increases in the use of marijuana at school, the likelihood of being offered drugs on school property, or the use of other substances.

In addition to using the national YRBS, the researchers drew on state YRBS data for the period 1993 through 2009 and data from the National Longitudinal Survey of Youth 1997 (NLSY97). None of these sources provided evidence that teenage marijuana use increases with the legalization of medical marijuana.

The YRBS and NLSY97 contain information on self-reported marijuana use. The researchers also analyzed the Treatment Episode Data Set (TEDS), which contains information on whether patients at federally funded drug treatment facilities tested positive for marijuana upon admission. The results suggested that legalization of medical marijuana was unrelated to the likelihood that patients ages 15-20 tested positive for marijuana.

"We are confident that marijuana use by teenagers does not increase when a state legalizes medical marijuana," said Montana State's Anderson, who studies health economics, risky behavior and crime.

Report: http://www.iza.org/en/webcontent/publications/papers/viewAbstract?dp_id=6592

In the eyes of young college men, it's more unethical to use steroids to get an edge in sports than it is to use prescription stimulants to enhance one's grades, according to new research published by the American Psychological Association.

And students who had themselves used stimulants without a prescription were more inclined to see such drug use as acceptable, according to the findings, which were published online in the APA journal Psychology of Addictive Behaviors. This is one of the first studies to compare perceptions of off-label prescription drug use with perceptions of steroids performance enhancers.

"This is consistent with the idea that using performance enhancers is viewed as less ethical in the sporting world than in the academic world," said the study's lead author, Tonya Dodge, PhD, of George Washington University. "Interestingly, the students in our study considered off-label prescription drug use as more effective for success than using steroids."

Approximately 1,200 college freshmen (73 percent white) at Pennsylvania State University answered a questionnaire that presented two scenarios. One described "Bill," a sprinter for his college track team who does not have a lot of time to train before the championship meet and is worried he won't be able to improve. He gets steroids from a friend and ends up performing better than expected and wins the championship race.

The second scenario presents "Jeff," a college student facing midterm exams who is worried that his grades in class may be low. He doesn't have much time to study so he gets some Adderall, a prescription stimulant, from a friend who tells him it will help him focus at exam time. Jeff takes the pills and ends up getting better midterm grades than he expected.

After reading both scenarios, the students were asked how strongly they agreed or disagreed with four statements: "Bill/Jeff is a cheater for using steroids/Adderall," and, "Taking steroids/Adderall was necessary for Bill/Jeff to do well."

The students were also asked if they had ever misused prescription stimulant drugs, such as Adderall, Ritalin or Dexedrine, or if they had ever used steroids. Less than 1 percent of the sample reported having ever used steroids while about 8 percent said they had misused prescription stimulants in the last 12 months. This compares to 8 percent to 34 percent of college students who have reported misusing prescription stimulants and 1.5 percent of adolescents and young adults who have misused anabolic steroids.

The researchers also asked the men if they had played a sport in high school to determine if that would affect their judgments.

Participants significantly rated Bill, the steroid user, as more of a cheater than Jeff, the prescription drug user. This difference got bigger if the students reported having misused prescription stimulants themselves in the past or if they had played a sport.

Overall, the students were more likely to consider Jeff's Adderall use more necessary to succeed than Bill's steroid use regardless of whether they had misused prescription stimulants in the past or had played a sport. "One reason students may have felt Adderall was more necessary than steroids for success is because people may believe intelligence is less malleable than athletic ability. This view of intelligence might have led the students in this study to believe that taking Adderall would increase intellectual capacity," said Dodge. "This research can help mold future prevention efforts around off-label prescription stimulant use in the academic world."

The American Psychological Association, in Washington, D.C., is the largest scientific and professional organization representing psychology in the United States and is the world's largest association of psychologists. APA's membership includes more than 137,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance psychology as a science, as a profession and as a means of promoting health, education and human welfare.

Article: "Judging Cheaters: Is Substance Misuse Viewed Similarly in the Athletic and Academic Domains?" Tonya Dodge, PhD, George Washington University and Skidmore College; Kevin J. Williams, PhD, University at Albany, State University of New York; Miesha Marzell, PhD, Pacific Institute for Research and Evaluation; Rob Turrisi, PhD, Pennsylvania State University; Psychology of Addictive Behaviors, online, April 2012.

Half of young adult tobacco smokers also have smoked marijuana in the last 30 days, according to a recent Facebook-based survey conducted by UCSF researchers, indicating a greater prevalence of marijuana and tobacco co-use among smokers age 18-25 than previously reported.

Other recent studies have shown that approximately 35 percent of young adult tobacco smokers used marijuana within the last month.

“We were curious whether rates would be different in our study where we reached out through social media and the Web,” said lead author Danielle Ramo, PhD, a post-doctoral scholar in the UCSF Department of Psychiatry. “And rates were much higher, which shows the problem might be larger than we realize.”

Survey participants were recruited solely online, a departure from traditional surveys that rely on face to-face interviews, phone interviews or completing questionnaires. The UCSF researchers primarily used Facebook through a series of paid advertisements, in addition to Craigslist and a survey sampling company to reach out to young adults. The results, the researchers said, indicate young adults might be more inclined to answer honestly via anonymous online sampling.

The research will be published in Addiction Science and Clinical Practice on April 18.

The first phase of the survey was used to identify tobacco smoking patterns only. A second stage asked participants to answer the tobacco and marijuana use survey, which employed data encryption to ensure anonymity and prevent multiple entries. Of the 3,500 individuals who completed the marijuana and tobacco co-use survey, usage was highest amongst Caucasians, people from the Northeast, people in rural areas and among the non-student population. Of the 68 percent who were daily smokers, 53 percent had used marijuana in the last month.

“Residence in a medical marijuana state was unrelated to the prevalence of marijuana use as well as the co-use of marijuana and tobacco in this young adult sample,” reported Judith Prochaska, PhD, MPH, associate professor of psychiatry at UCSF and the study’s senior author. “The prevalence of marijuana use also did not differ by respondents’ age, income or gender.”

The research shows that smoking cessation programs aimed at this age group should take into account the effect of marijuana use in their programs, according to Ramo. The next phase of the research is to adapt behavioral and cognitive principles for smoking cessation, like counseling, to Facebook.

“Adapting the social media aspect into intervention and incorporating the social environment are new ways to approach finding the most effective means for treatment,” she said.

Ramo and Prochaska plan to use social media such as Facebook, in which participants will be able to contact not only the clinicians for support, but also other smokers within the online community. Motivational Facebook messages and formal moderated groups online also will be integrated into treatment.

“This format allows them to remain anonymous as much as they want, but have ease to access interventions when they are at the age when they are less likely to enter a treatment center, research lab or clinic,” Ramo said.

The study was supported by an institutional training grant, a center grant from the National Institute on Drug Abuse and an individual Postdoctoral Fellowship Award from the California Tobacco-Related Diseases Research Program. The authors have no competing interests related to this research.

UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.

 Young adults often experiment with hard drugs, such as cocaine, amphetamines and opiates, and all but about 10 percent stop as they assume adult roles and responsibilities. Those still using hard drugs into their 50s are five times more likely to die earlier than those who do not, according to a new study by University of Alabama at Birmingham researchers published online Jan. 27, 2012, in the Journal of General Internal Medicine.

According to the National Survey on Drug Use and Health, 9.4 percent of Americans ages 50-59 and 7 percent of adults ages 35-49 reported use of a drug other than marijuana sometime in the past year. The study’s lead author, Stefan Kertesz, M.D., associate professor in the UAB Division of Preventive Medicine. and colleagues attempted to discover if lifelong hard-drug use shortens lifespan to better enable primary-care doctors to advise patients who use drugs recreationally.

“While government guidelines have not endorsed screening for drugs in primary care, many doctors are challenged when they discover patients continue to dabble with them,” Kertesz says. “In primary-care practice, we often hear from stable patients who report using some cocaine, irregularly, perhaps on weekends. It’s an underappreciated but very common situation. The typical question physicians have to ask is ‘If this patient doesn’t have addiction, what advice can I give other than noting that it’s unwise to break the law?’ After all, we are supposed to be doctors, not law enforcement.”

Kertesz and a research team from other universities looked at data from the Coronary Artery Risk Development in Young Adults Study for their analysis. CARDIA, funded by the National Heart, Lung and Blood Institute, is a long-term research project involving more than 5,000 black and white men and women from Birmingham, Chicago, Minneapolis and Oakland, designed to examine the development and determinants of cardiovascular disease and its risk factors. Participants ages 18-30 were recruited and followed from 1985 to 2006.

The research team looked specifically at the reported use of “hard drugs” by 4,301 of the CARDIA participants. They compared people who stopped drug use early to those who continued and calculated the likelihood of premature death among these groups.

“Fourteen percent of the people in the study reported recent hard-drug use at least once, and of these, half continued using well into middle age,” Kertesz says. “But, most of the drug users in our study were not addicts. They were dabblers who used just a few days a month.”

Kertesz and his colleagues found that older hard-drug users were more likely to report being raised in economically challenged circumstances in a family that was unsupportive, abusive or neglectful. The team also found that those who were heavy drug users into young adulthood and continued at lower levels into middle age were roughly five times more likely to die than persons who didn’t use drugs.

“We can’t assume that drugs caused death, as in an overdose,” he says. “Rather what we found is that middle-age adults who continue to dabble in hard drugs represent a group that is at risk of bad outcomes — which could include death from trauma, heart disease or other causes that are not a direct result of their drug use — at a higher rate than people who stopped using drugs.”

Kertesz added that the team’s findings are a reminder that people who continue to use drugs are potentially quite vulnerable. They often have grown up under economic and psychosocial stress from childhood onward. They continue to smoke and drink and they remain at elevated risk of premature death.

“Based on the data we hope to offer better advice to primary-care doctors struggling with the rising tide of drug-taking by adults who have not left behind many of the bad habits they learned in young adulthood,” he says.

Study co-authors include Yulia Khodneva, M.D., Monika Safford, M.D., and Joseph Schumacher, Ph.D., UAB Division of Preventive Medicine; Jalie Tucker, Ph.D., UAB School of Public Health; Joshua Richman, M.D., Ph.D., UAB Department of Surgery; Bobby Jones, Ph. D., Department of Statistics, Carnegie Mellon University; and Mark J. Pletcher, M.D., departments of Epidemiology & Biostatistics and Medicine, University of California, San Francisco.

Mark Twain said, "Giving up smoking is the easiest thing in the world. I know because I've done it thousands of times." Many smokers would agree that it's difficult to stay away from cigarettes. A new study in Biological Psychiatry this month now suggests that low dopamine levels that occur as a result of withdrawal from smoking actually promote the relapse to smoking.

Dopamine is a brain chemical messenger that is critically important in reward and motivation. Some research suggests that one of its central roles is to send a signal to the brain to 'seek something enjoyable'. Indeed, dopamine is released during many rewarding experiences, including taking drugs, smoking, having sex, and eating food.

This signal seems to depend on the dopamine which is released in response to environmental cues, called phasic release, as opposed to the tonic seepage of small amounts of dopamine from nerve cells. The tonic release of dopamine is implicated in helping the dopamine system set the level of its reactivity to inputs.

Since dopamine is released by smoking, it makes sense that dopamine levels become abnormal when a smoker chooses to stop smoking. Researchers from Baylor College of Medicine in Texas undertook their study to characterize these changes.

They studied mice that were administered nicotine, the active constituent of cigarettes, for several weeks. The researchers then withheld the nicotine and measured the subsequent alterations in dopamine signaling during the withdrawal period.

They reported that withdrawal from nicotine produced a deficit in dopamine in which the basal dopamine concentration and tonic dopamine signals were disproportionately lower than the phasic dopamine signals. Re-exposure to nicotine reversed the hypodopaminergic state.

"This study is an elegant example of yet another way that addiction 'hijacks' the reward system. The phasic release of dopamine triggers us to seek things that, in theory, help us to adapt to our environment," commented Dr. John Krystal, editor of Biological Psychiatry. "However, in addiction the phasic release of dopamine is heightened and it triggers the pursuit of abused substances. This disturbance of dopamine function would, conceivably, make it that much harder to avoid seeking drugs of abuse."

According to the authors, these findings indicate that medications which could help elevate tonic dopamine levels during withdrawal may be successful treatment strategies for nicotine-dependent individuals attempting to quit smoking. Theoretically, such a treatment could help normalize any fluctuating dopamine levels from the sudden lack of nicotine, and also lessen the dopamine-influenced urges to seek out the nicotine, leading to relapse.

NewsPsychology (Mar. 5, 2012) — Researchers from Boston University Schools of Medicine (BUSM) and Public Health along with Boston Medical Center have found children’s academic achievement test scores not affected by intrauterine exposure to cocaine, tobacco or marijuana. However, alcohol exposure in children who had no evidence of fetal alcohol syndrome (FAS) did lead to lower scores in math reasoning and spelling even after controlling for other intrauterine substance exposures and contextual factors.

These findings currently appear on-line in the journal of Vulnerable Children and Youth Studies.

There has been widespread concern that intrauterine cocaine exposure (IUCE) may have harmful effects on children’s academic performance, particularly at higher grades

requiring abstract reasoning and greater attention and control. Also unresolved is whether other intrauterine exposures, such as alcohol (IUAE), tobacco, and marijuana, which often co-occur with IUCE, independently affect children’s academic abilities after controlling for other exposures.

Academic achievement scores (Wechsler Individual 15 Achievement Test-Second Edition (WIAT-II) were collected from 119, low-income, urban 11-year-olds who had been enrolled in a prospective longitudinal study of IUCE. The results indicate that neither IUCE nor intrauterine exposure to marijuana or tobacco was associated with lower WIAT-II scores.

“Our results are consistent with growing evidence that IUCE exposure does not independently predict poorer achievement scores in school-age children exposed to multiple other substance exposures and psychosocial stressors,” explained lead author Ruth Rose-Jacobs, ScD, associate professor of pediatrics at BUSM and a research scientist at BMC.

However, according to Rose-Jacobs, the negative associations of IUAE on arithmetic reasoning and spelling were significant because the analyses had controlled for other substances; the children did not have FAS and had not been born preterm, all of which might negatively influenced achievement scores. The relationship between IUAE and achievement scores in this sample was partially explained on the Children’s Depression Inventory. Children’s depressive symptoms could precede or be a response to school achievement difficulties but whatever the pathway, relatively low achievement scores of children with IUAE are of potential educational importance. “Study finding suggest the children with histories of even low-level IUAE who experience school difficulties should be evaluated particularly for arithmetic skills and depressive symptoms and offered enhanced educational methods/interventions tailored to their needs,” she added.

Funding for the study was provided by the National Institute on Drug Abuse, the National Center for Research Resources and the National Institutes of Health (NIH).

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Story Source:

The above story is reprinted from materials provided by Boston University Medical Center.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Ruth Rose-Jacobs, Marilyn Augustyn, Marjorie Beeghly, Brett Martin, Howard J. Cabral, Timothy C. Heeren, Mark A. Richardson, Deborah A. Frank. Intrauterine substance exposures and Wechsler Individual Achievement Test-II scores at 11 years of age. Vulnerable Children and Youth Studies, 2012; : 1 DOI: 10.1080/17450128.2011.648967

Several decades ago, a number of clinics used LSD to treat alcoholism with some success. But until now, no research has pulled together the results of these trials to document exactly how effective LSD was. Now a new meta-analysis of randomized controlled trials of the drug, available in the Journal of Psychopharmacology, published by SAGE, provides evidence for a clear and consistent beneficial effect of LSD for treating alcohol dependency.

Teri Krebs and Pål-Ørjan Johansen are both affiliated with the Department of Neuroscience at the Norwegian University of Science and Technology (NTNU), Trondheim, Norway. During research fellowships at Harvard Medical School, Boston, USA, they spotted a gap in the understanding of lysergic acid diethylamide's (LSD's) potential for alcoholism treatment. No researcher had ever performed a quantitative meta-analysis of previous clinical trials using the drug.

Krebs and Johansen set out to independently extract data from previous randomized, controlled clinical trials, pooling their results. They identified six eligible trials, all carried out in the late 1960s and early 1970s. These included 536 participants, the vast majority of whom were male in-patients enrolled in alcohol-focused treatment programs. Individuals with a history of schizophrenia or psychosis were excluded from the original trials. The control conditions included low-dose LSD, stimulants, or non-drug control conditions. Each trial used clearly defined treatment-independent and standardized methods to assess outcomes on alcohol misuse.

While the experiments varied in the dosage used and the type of placebo physicians administered to patients, LSD had a beneficial effect on alcohol misuse in every trial. On average, 59 percent of LSD patients and 38 percent of control patients were improved at follow-up using standardized assessment of problem alcohol use. There was also a similar beneficial effect on maintained abstinence from alcohol. The positive effects of a single LSD dose — reported both in these and in other, non-randomized trials — lasts at least six months and appears to fade by 12 months.

Regarding the lasting effects of the LSD experience in alcoholics, investigators of one trial noted, "It was rather common for patients to claim significant insights into their problems, to feel that they had been given a new lease on life, and to make a strong resolution to discontinue their drinking." And investigators of another trial noted, "It was not unusual for patients following their LSD experience to become much more self-accepting, to show greater openness and accessibility, and to adopt a more positive, optimistic view of their capacities to face future problems."

LSD interacts with a specific type of serotonin receptors in the brain, which may stimulate to new connections and open the mind for new perspectives and possibilities, Krebs explains. LSD is not known to be addictive or toxic to the body, but the LSD has striking effects on imagination, perception, and memories and can elicit periods of intense anxiety and confusion.

"Given the evidence for a beneficial effect of LSD on alcoholism, it is puzzling why this treatment approach has been largely overlooked," says Johansen. The authors suggest a number of reasons for this: many of the individual trials did not have enough patients to confidently conclude that there was a beneficial effect of LSD, but when pooled together the trials shows a clear and consistent effect; trial authors expected unrealistic results from a single dose of LSD and tended to discount moderate or short-term effects and; earlier non-randomized clinical trials reporting promising results but had methodological problems, creating the misunderstanding that well-designed studies did not exist or failed to find a beneficial effect. Finally, the complicated social and political history of LSD meant that obtaining regulatory approval for clinical trials became laborious, although national and international drug control measures have never banned treatment development or medical use of LSD.

Its unusual for a psychiatric medication to have a positive treatment effect lasting for several months after a single dose. Krebs and Johansen suggest that repeated doses of LSD coupled with modern, evidence-based alcohol relapse prevention treatments might provide more sustained results. They also note that plantbased psychedelics such as mescaline and ayahuasca which are used by Native Americans to promote mental health and sustained sobriety, merit further investigation for alcoholism treatment.

 Using marijuana carries legal risks, but the consequences of occasionally lighting up do not include long-term loss of lung function, according to a new study in the Jan. 11, 2012, issue of the Journal of the American Medical Association.

Marijuana is the most commonly used illicit drug in the United States, according to the National Survey on Drug Use and Health. In 2009, 16.7 million Americans ages 12 and older reported using marijuana at least once in the month prior to being surveyed. In addition, since 1996, 16 states and Washington, D.C., have legalized the medical use of marijuana to help manage the symptoms of many diseases, including cancer, AIDS and glaucoma.

"With marijuana use increasing and large numbers of people who have been and continue to be exposed, knowing whether it causes lasting damage to lung function is important for public-health messaging and medical use of marijuana," says the study's senior author, University of Alabama at Birmingham associate professor Stefan Kertesz, M.D.

Kertesz, of the UAB Division of Preventive Medicine and the Center for Surgical, Medical and Acute Care Research and Transitions at the Veterans Affairs Medical Center in Birmingham, says it's long been known that marijuana smoke has many irritant chemicals found in tobacco smoke and can cause lung irritation, wheezing and cough immediately after use; however, the research on long-term effects on lung function have inconsistencies.

Using a large national database, the research team compared the lung function of marijuana and tobacco smokers during a 20-year period. The data revealed that tobacco smoke had exactly the effect shown in all prior studies — increasing a person's cumulative exposure to cigarettes results in loss of air flow and lung volumes; the opposite was true for marijuana smoke.

"At levels of marijuana exposure commonly seen in Americans, occasional marijuana use was associated with increases in lung air flow rates and increases in lung capacity," Kertesz says. "Those increases were not large, but they were statistically significant. And the data showed that even up to moderately high-use levels — one joint a day for seven years — there is no evidence of decreased air-flow rates or lung volumes."

Kertesz cautions that smoking marijuana is not an avenue to better lung health.

"It's not enough of an increase that would make you feel better," he says "Healthy adults can blow out 3 to 4 liters of air in one second. The amount of gain, on average, from marijuana is small, 50 ccs or roughly a fifth of a can of coke. So it's not something that would be noticeable."

Also, Kertesz says, the increase does not hold steadfast over time.

"The relationship changes for people who get to high levels of lifetime exposure," he says. "At that point, the data suggests there is a decline in lung air-flow rate. There also may be other damaging effects that don't manifest until extremely high levels of exposure; we did not have enough very heavy marijuana smokers in this study to determine this."

To perform their analysis, Kertesz and a research team from other universities looked at data from the Coronary Artery Risk Development in Young Adults Study. CARDIA, funded by the National Heart, Lung and Blood Institute, is a long-term research project involving more than 5,000 black and white men and women from Birmingham, Chicago, Minneapolis and Oakland, designed to examine the development and determinants of cardiovascular disease and its risk factors. Participants were recruited when they were ages 18-30 and followed from 1985 to 2006.

The researchers looked closely at the reported use of both marijuana and tobacco and asked participants repeatedly during years of follow-up about their use of these substances. Marijuana and tobacco use were both commonly reported — 37 percent said they used marijuana at some point during the study. This is similar, the researchers say, to what many Americans have said in other national surveys.

As part of the CARDIA protocol, participants' lung function was measured for air flow and lung volume at years 0, 2, 5, 10 and 20 using standard pulmonary function tests. The air flow measure is the amount of air you can blow out of your lungs in one second after taking the deepest breath possible. The volume measure is the total amount of air you can blow out after taking the deepest breath possible.

Lead author, Mark J. Pletcher, M.D., of the Department of Epidemiology and Biostatistics, and Department of Medicine at the University of California, San Francisco, who led the statistical analysis, says what sets this study apart from any others is both the number of participants and duration of the study.

"This is not the first study to show that marijuana has a complicated relationship with lung function. However, the size of the study and the long duration of follow-up help us to paint a clearer picture of the ways in which the relationship changes over time," he says.

As a final note, Kertesz clarified that the study did not examine other ways in which smoking marijuana could affect a person's health and insisted this study does not advocate the use of marijuana.

"Marijuana is still an illegal drug, and it has many complicated effects on the human body and its function," he says. "In our findings we see hints of harm in pulmonary function with heavy use, and other studies have shown that marijuana use increases a user's likelihood of a heart attack, according to the American Heart Association, and impairs the immune system's ability to fight disease, according to the National Institute on Drug Abuse."

The study was funded by the National Institute on Drug Abuse and National Heart Lung Blood Institute.

Study co-authors include Eric Vittinghoff, Ph.D. and Feng Lin, M.S., Department of Epidemiology and Biostatistics, University of California, San Francisco; Ravi Kalhan, M.D., M.S., Asthma-COPD Program, Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine; Joshua Richman, M.D., Ph.D., UAB Department of Surgery and Center for Surgical, Medical and Acute Care Research and Transitions, Veterans Affairs Medical Center, Birmingham; Monika Safford, M.D., UAB Division of Preventive Medicine; and Stephen Sidney, M.D., Kaiser Permanente Division of Research, Oakland, Calif.

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Journal Reference:

1. M. J. Pletcher, E. Vittinghoff, R. Kalhan, J. Richman, M. Safford, S. Sidney, F. Lin, S. Kertesz. Association Between Marijuana Exposure and Pulmonary Function Over 20 Years. JAMA: The Journal of the American Medical Association, 2012; 307 (2): 173 DOI: 10.1001/jama.2011.1961

— Different ingredients in marijuana appear to affect regions of the brain differently during brain processing functions involving responses to certain visual stimuli and tasks, according to a report in the January issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Sagnik Bhattacharyya, M.B.B.S., M.D., Ph.D, at the Institute of Psychiatry, King's College in London, and colleagues studied 15 healthy men, who were occasional marijuana users, to examine the effects of Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) on regional brain function during salience processing, which is how people perceive things around them.

The authors used functional MRI images to study each participant on three occasions after administration of Δ9-THC, CBD or placebo. Study participants performed a visual oddball task of pressing buttons according to the direction arrows on a screen were pointing, as a measure of attentional salience processing.

"Pairwise comparisons revealed that Δ9-THC significantly increased the severity of psychotic symptoms compared with placebo and CBD whereas there was no significant difference between the CBD and placebo conditions," the authors conclude.

Δ9-THC had a greater effect than placebo on reaction time to nonsalient relative to salient stimuli. This was associated with modulation of both prefrontal and striatal function by Δ9-THC, augmenting (increasing) activation in the former region and attenuating (weakening) it in the latter.

"Moreover, in the present study, the magnitude of Δ9-THC's effect on response times to nonsalient stimuli was correlated with its effect on activation in the right caudate, the region where the physiological effect of Δ9-THC was linked to its induction of psychotic symptoms," the authors write.

They conclude that "collectively, these observations suggest that Δ9-THC may increase the aberrant attribution of salience and induce psychotic symptoms through its effects on the striatum and lateral prefrontal cortex."

When the effects of CBD were contrasted with Δ9-THC and placebo with respect to the visual task there was a "significant effect" in the left caudate with CBD augmenting (increasing) the response and Δ9-THC attenuating (weakening) it.

"These effects suggest that CBD may also influence the effect of cannabis use on salience processing — and hence psychotic symptoms — by having an opposite effect, enhancing the appropriate response to salient stimuli," the authors wrote.

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Journal Reference:

1. S. Bhattacharyya, J. A. Crippa, P. Allen, R. Martin-Santos, S. Borgwardt, P. Fusar-Poli, K. Rubia, J. Kambeitz, C. O'Carroll, M. L. Seal, V. Giampietro, M. Brammer, A. W. Zuardi, Z. Atakan, P. K. McGuire. Induction of Psychosis by  9-Tetrahydrocannabinol Reflects Modulation of Prefrontal and Striatal Function During Attentional Salience Processing. Archives of General Psychiatry, 2012; 69 (1): 27 DOI: 10.1001/archgenpsychiatry.2011.161