The study, published in the January issue of Neurogastroenterology and Motility, looked at 226 patients seen at the Mayo Clinic in Rochester, New York, USA, over a 13-year period.

These were broken into three groups. Eighty-two patients with CVS were randomly matched with 82 patients with Irritable Bowel Syndrome (IBS) based on age, gender and geographic referral region. Researchers also examined the records of 62 patients with functional vomiting (FV), recurrent vomiting that cannot be attributed to a specific physical or psychiatric cause.

“Our study showed that CVS and FV had very similar clinical features, apart from marijuana use” says Dr G Richard Locke III from the Division of Gastroenterology and Hepatology at the Clinic.

Key findings of the study included:

• Members of the CVS group were younger than members of the FV group (30 versus 36 years) and more likely to be male (53% versus 46%).

• No statistically significant association was detected between membership of the CVS and FV groups and marital status, education level, body mass index, employment status, alcohol use or smoking history.

• 37% of the CVS group had used marijuana (81% male), together with 13% of the FV group (equally split between male and female) and 11% of the IBS group (73% male).

• Marijuana users were 2.9 times more likely to be in the CVS group than the FV group. When this was adjusted for age and gender, males using marijuana were 3.9 times more likely to be in the CVS group and women using marijuana were 1.2 times more likely.

The research team also looked at gastrointestinal symptoms and migraine as these have previously been associated with CVS. They found that

• The prevalence of gastrointestinal symptoms, including abdominal pain and nausea, was similar in CVS and FV patients, with the exception of retching, which was more common in patients with CVS (69% versus 31%).

• Patients in the CVS group were more likely to have headaches and migraines than patients in the FV group, but the difference was not statistically significant. Migraine headache and psychiatric disorders did not appear to commonly co-exist in CVS patients, unlike in the IBS group.

• The researchers also measured rapid gastric emptying, which is when undigested food enters the small bowel too quickly causing nausea, vomiting and other symptoms. This showed that there were much higher rates of fast gastric emptying in patients in the CVS and FV group (45% and 46% respectively), compared with the IBS group (8%). A novel finding was that the patterns of fast, normal and delayed gastric emptying were similar in the CVS and FV groups.

“Our study confirms that cyclic vomiting syndrome occurs most often in young males and is significantly associated with marijuana use, unlike functional vomiting” says Dr Locke. “The current treatment options for this condition remain challenging and are limited by the lack of randomised controlled trials. Further research is clearly needed.”

The findings, reported online Dec. 5 in the Archives of General Psychiatry, add to the growing evidence that Ecstasy produces long-lasting serotonin neurotoxicity in humans, said Ronald Cowan, M.D., Ph.D., associate professor of Psychiatry.

“Our study provides some of the strongest evidence to date that the drug causes chronic loss of serotonin in humans.”

The neurotransmitter serotonin, a critical signaling molecule, has roles in regulating mood, appetite, sleep, learning and memory.

The current study is important, Cowan said, because MDMA (Ecstasy’s chemical name) may have therapeutic benefits and is now being tested as a treatment for post-traumatic stress disorder and anxiety associated with cancer.

“It’s essential that we understand the risk associated with using Ecstasy,” Cowan said. “If news keeps coming out that MDMA is being tested therapeutically and is safe, more people will tend to self-administer the drug. We need to know the dose at which this drug becomes toxic.

“Our studies suggest that if you use Ecstasy recreationally, the more you use, the more brain changes you get.”

In the current study, Cowan and colleagues used positron emission tomography (PET) imaging to examine the levels of serotonin-2A receptors in various brain regions, in females who had used Ecstasy (but not in the 90 days prior to imaging) and in females who had never used the drug. They limited their studies to females because previous work has shown gender-specific differences in serotonin receptor levels.

They found that Ecstasy users had increased levels of serotonin-2A receptors and that higher lifetime use of the drug (higher doses) correlated with higher serotonin receptor levels. The findings are consistent with some studies in animal models, with receptor levels increasing to compensate for the loss of serotonin, Cowan said.

Cowan and colleagues reported earlier this year that Ecstasy increased brain activation in three brain areas associated with visual processing, which suggested a loss in brain efficiency. Together, the two studies provide compelling evidence that Ecstasy causes lasting changes in brain serotonin function, Cowan said.

“It’s really critical to know whether or not this drug is causing long-term brain damage because millions of people are using it,” he said.

The 2010 National Survey on Drug Use and Health estimated that 15.9 million individuals 12 years or older in the United States had used Ecstasy in their lifetime; 695,000 people had used Ecstasy in the month prior to being surveyed.

Cowan is interested in determining the doses of Ecstasy that are toxic, and whether there are genetic vulnerabilities to toxicity. If clinical trials show that the drug has therapeutic benefits, it’s critical to know the risks, he said.

The collaborative study, led by Dr Matt Jones from the University’s School of Physiology and Pharmacology, tested whether the detrimental effects of cannabis on memory and cognition could be the result of ‘disorchestrated’ brain networks.

Brain activity can be compared to performance of a philharmonic orchestra in which string, brass, woodwind and percussion sections are coupled together in rhythms dictated by the conductor. Similarly, specific structures in the brain tune in to one another at defined frequencies: their rhythmic activity gives rise to brain waves, and the tuning of these brain waves normally allows processing of information used to guide our behaviour.

Using state-of-the-art technology, the researchers measured electrical activity from hundreds of neurons in rats that were given a drug that mimics the psychoactive ingredient of marijuana. While the effects of the drug on individual brain regions were subtle, the drug completely disrupted co-ordinated brain waves across the hippocampus and prefrontal cortex, as though two sections of the orchestra were playing out of synch.

Both these brain structures are essential for memory and decision-making and heavily implicated in the pathology of schizophrenia.

The results from the study show that as a consequence of this decoupling of hippocampus and prefrontal cortex, the rats became unable to make accurate decisions when navigating around a maze.

Dr Jones, lead author and MRC Senior Non-clinical Fellow at the University, said: “Marijuana abuse is common among sufferers of schizophrenia and recent studies have shown that the psychoactive ingredient of marijuana can induce some symptoms of schizophrenia in healthy volunteers. These findings are therefore important for our understanding of psychiatric diseases, which may arise as a consequence of ‘disorchestrated brains’ and could be treated by re-tuning brain activity.”

Michal Kucewicz, first author on the study, added: “These results are an important step forward in our understanding of how rhythmic activity in the brain underlies thought processes in health and disease.”

Young people who are genetically vulnerable to depression should be extra careful about using cannabis: smoking cannabis leads to an increased risk of developing depressive symptoms.

This has emerged from research carried out by Roy Otten at the Behavioural Science Institute of Radboud University Nijmegen that is published in the online version of the scientific journal Addiction Biology. Two-thirds of the population have the gene variant that makes one sensitive to depression.

Many young people in the Netherlands use cannabis. Nearly 30% of 16-year-olds indicate that they have used cannabis on at least one occasion, and 12% that they have used it during the past month. Besides worse performances at school, the use of cannabis also increases the risk of developing schizophrenia and psychosis.

Smoking hashish and weed were thought to increase the risk of depression but no conclusive evidence for this was available to date. Otten suspects that this is partly because his predecessors failed to consider the individual genetic vulnerability to depression.

Over a five-year period, data were collected from 428 families and their two adolescent children. Each year the children answered questions on topics such as their behaviour and depressive symptoms. The variant of the serontonin gene (5-HTT) responsible for increased vulnerability to developing depression was also determined.

In young people with a special variant of the gene, cannabis use led to an increase of depressive symptoms.

“The effect is robust,” the authors of the study said. “It still remains, even if you take into account a series of other variables that could cause the effect, such as smoking behaviour, alcohol use, upbringing, personality and socio- economic status. Some people might think that young people with a disposition for depression would start smoking cannabis as a form of self-medication, and that the presence of depressive symptoms is therefore the cause of cannabis use.”

“However, in the longer term that is definitely not the case. Although the immediate effect of cannabis may be pleasant and cause a feeling of euphoria, in the longer term we observe that cannabis use leads to an increase in depressive symptoms in young people with this specific genotype.”

Knowing what the negative effects of cannabis use could be is important because although cannabis may cause an immediate euphoric feeling, for a large group in the population its use can lead to an increase of depressive symptoms in the longer term.

According to the investigators 8 of 9 studies found that drivers who use marijuana are significantly more likely to be involved in crashes than drivers who do not. Only one small case-control study conducted in Thailand, where the prevalence of marijuana use is far lower than reported elsewhere, was the exception.

Full study findings are published online in Epidemiologic Reviews.

The analysis indicates that 28% of fatally injured drivers and more than 11% of the general driver population tested positive for non-alcohol drugs, with marijuana being the most commonly detected substance.

Guohua Li, MD, DrPh, professor of Epidemiology at Columbia University’s Mailman School of Public Health, and senior author points out that although this analysis provides compelling evidence for an association between marijuana use and crash risk, one should be cautious in inferring causality from these epidemiologic data alone. However, “if the crash risk associated with marijuana is confirmed by further research, this is likely to have major implications for driving safety and public policy. It also would play a critical role in informing policy on the use of medical marijuana.”

“Given the ongoing epidemic of drug-impaired driving and the increased permissibility and accessibility of marijuana for medical use in the U.S., it is urgent that we better understand the role of marijuana in causing car accidents.”

“Subjects in the present study were significantly impaired during MDMA treatments when deprived of sleep for one night,” the study found. “However, the prime factor causing these impairments was sleep deprivation rather than the use of MDMA itself”

“When applied in courts, one could rightfully pose the argument that such drivers should not be prosecuted for DUI since MDMA did not contribute to the impairments of the driver.”

Studies have found that regular recreational doses of ecstasy can improve some aspects of driving performance when administered during the day, but can also cause those under its influence to overreacted to speed decelerations.

Researchers from Germany and the Netherlands wondered how the drug would effect drivers who had stayed awake at a rave all night.

They gave eight healthy males and eight healthy females who had experience with ecstasy a single doses of placebo and various doses of the drug. The researchers then assessed the participants driving performance in the evening and in the morning after a night of sleep loss.

The study found that all of the participants had severe impairment in driving performance, but there was not a significant difference between those who had taken ecstasy and those who had taken a placebo.

Although MDMA did not appear to have an effect on driving performance for better or worse, the researchers warned that it could still prove troublesome for potential drivers.

“During MDMA intoxication, they may not be able to subjectively experience the debilitating effects of sleep loss to the same degree as drug-free drivers, because they feel energetic,” the researchers said. “As a consequence, they may decide to drive because they feel alert, thereby neglecting the impairing effects of other impairing factors such as sleep deprivation or even alcohol use.”

Lasting change was found in the part of the personality known as openness, which includes traits related to imagination, aesthetics, feelings, abstract ideas and general broad-mindedness. Changes in these traits, measured on a widely used and scientifically validated personality inventory, were larger in magnitude than changes typically observed in healthy adults over decades of life experiences, the scientists say. Researchers in the field say that after the age of 30, personality doesn’t usually change significantly.

“Normally, if anything, openness tends to decrease as people get older,” says study leader Roland R. Griffiths, a professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine.

The research, approved by Johns Hopkins’ Institutional Review Board, was funded in part by the National Institute on Drug Abuse and published in the Journal of Psychopharmacology.

The study participants completed two to five eight-hour drug sessions, with consecutive sessions separated by at least three weeks. Participants were informed they would receive a “moderate or high dose” of psilocybin during one of their drug sessions, but neither they nor the session monitors knew when.

During each session, participants were encouraged to lie down on a couch, use an eye mask to block external visual distraction, wear headphones through which music was played and focus their attention on their inner experiences.

Personality was assessed at screening, one to two months after each drug session and approximately 14 months after the last drug session. Griffiths says he believes the personality changes found in this study are likely permanent since they were sustained for over a year by many.

Nearly all of the participants in the new study considered themselves spiritually active (participating regularly in religious services, prayer or meditation). More than half had postgraduate degrees. The sessions with the otherwise illegal hallucinogen were closely monitored and volunteers were considered to be psychologically healthy

“We don’t know whether the findings can be generalized to the larger population,” Griffiths says.

As a word of caution, Griffiths also notes that some of the study participants reported strong fear or anxiety for a portion of their daylong psilocybin sessions, although none reported any lingering harmful effects. He cautions, however, that if hallucinogens are used in less well supervised settings, the possible fear or anxiety responses could lead to harmful behaviors.

Griffiths says lasting personality change is rarely looked at as a function of a single discrete experience in the laboratory. In the study, the change occurred specifically in those volunteers who had undergone a “mystical experience,” as validated on a questionnaire developed by early hallucinogen researchers and refined by Griffiths for use at Hopkins. He defines “mystical experience” as among other things, “a sense of interconnectedness with all people and things accompanied by a sense of sacredness and reverence.”

Personality was measured on a widely used and scientifically validated personality inventory, which covers openness and the other four broad domains that psychologists consider the makeup of personality: neuroticism, extroversion, agreeableness and conscientiousness. Only openness changed during the course of the study.

Griffiths says he believes psilocybin may have therapeutic uses. He is currently studying whether the hallucinogen has a use in helping cancer patients handle the depression and anxiety that comes along with a diagnosis, and whether it can help longtime cigarette smokers overcome their addiction.

“There may be applications for this we can’t even imagine at this point,” he says. “It certainly deserves to be systematically studied.”

Along with the National Institute on Drug Abuse, this study was funded by the Council on Spiritual Practices, Heffter Research Institute and the Betsy Gordon Foundation.

Other Hopkins authors of the research include Matthew W. Johnson, Ph.D., and Katherine A. MacLean, Ph.D.

“We found that there is a ‘window of opportunity’ during which administering synthetic marijuana helps deal with symptoms simulating PTSD in rats,” said Dr. Irit Akirav of the University of Haifa’s Department of Psychology, who led the study.

In the study, which Dr. Akirav conducted with research student Eti Ganon-Elazar, the researchers set out to examine how administering cannabinoids (synthetic marijuana) affects the development of PTSD-like symptoms in rats, whose physiological reactions to traumatic and stressful events is similar to human reactions.

In the first part of the study, the researchers exposed a group of rats to extreme stress, and observed that the rats did indeed display symptoms resembling PTSD in humans, such as an enhanced startle reflex, impaired extinction learning, and disruption of the negative feedback cycle of the stress-influenced HPA axis.
The rats were then divided into four groups. One was given no marijuana at all; the second was given a marijuana injection two hours after being exposed to a traumatic event; the third group after 24 hours and the fourth group after 48 hours.

A week later, the researchers examined the rats and found that the group that had not been administered marijuana and the group that got the injection 48 hours after experiencing trauma continued to display PTSD symptoms as well as a high level of anxiety.

By contrast, the PTSD symptoms disappeared in the rats that were given marijuana 2 or 24 hours after experiencing trauma, even though these rats had also developed a high level of anxiety.

“This indicates that the marijuana did not erase the experience of the trauma, but that it specifically prevented the development of post-trauma symptoms in the rat model,” said Dr. Akirav, who added that the results suggest there is a particular window of time during which administering marijuana is effective. Because the human life span is significantly longer than that of rats, Dr. Akirav explained, one could assume that this window of time would be longer for humans.

The second stage of the study sought to understand the brain mechanism that is put into operation during the administering of marijuana. To do this, they repeated stage one of the experiment, but after the trauma they injected the synthetic marijuana directly into the amygdala area of the brain, the area known to be responsible for response to trauma. The researchers found that the marijuana blocked development of PTSD symptoms in these cases as well. From this the researchers were able to conclude that the effect of the marijuana is mediated by a CB1 receptor in the amygdala.

Past studies have shown that athletes generally smoke marijuana less often than other college students do.

“But there is still a pretty large number who choose to use it,” said Jennifer F. Buckman, Ph.D., of the Center of Alcohol Studies at Rutgers University in Piscataway, New Jersey.

Because marijuana could have ill health effects—and possibly hurt athletic performance—that begs the question of why college athletes would use it, according to Buckman.

So for the new study, she and her colleagues surveyed 392 college athletes and 504 non-athlete students about marijuana use. Among men, one-third of athletes said they’d used the drug in the past year, versus half of non-athletes; the same was true of 25% of female athletes and 48% of non-athletes.

Overall, athletes and non-athletes shared many of the same risk factors for marijuana use such as being white, being a cigarette smoker and having an exaggerated perception of how many of their peers use the drug. But there were some differences too.

“One thing that stood out is that athletes were more likely to use marijuana because they thought it was pleasurable,” Buckman said.

They were less likely, on the other hand, to use the drug for reasons like dealing with stress. That suggests that athletes largely smoke marijuana recreationally, rather than as a way of coping with life problems.

The exception, though, might be male athletes who keep using marijuana during their competitive season. The study found that these athletes reported more problems with anxiety and negative mood, and appeared more likely to use the drug for coping with stress compared with the male athletes who avoided marijuana during their competitive season.

“That’s a really interesting finding, and it’s a direction for research to go in the future,” Buckman said. “What are the stressors for these athletes? Is it academic? Is it the athletic competition?”

The ultimate goal in studies like these, Buckman noted, is to uncover factors that seem to influence drug use, then develop specific messages most likely to make a difference with a specific group.

As an example, she pointed to the finding that female students with body-image worries were more likely to use marijuana than women without such concerns. Because the survey was done at one time point, it’s not clear which came first: the marijuana use or the poor body image.

But since marijuana is well known to cause the “munchies,” and particularly a yen for sweets, it’s possible that the drug use came first.

Whatever the reason, college women—and especially athletes who need to stay fit—might listen to anti-marijuana messages that emphasize the effects on eating.

More studies are needed to uncover the reasons that young people start using marijuana, despite the potential health and legal consequences, according to Buckman.

“This is a very commonly used drug,” Buckman said, “and we just need to understand more about the factors that influence people to use it.”

But headlines like one in Time magazine’s health section in February – “Ecstasy as therapy: have some of its negative effects been overblown?” – concern Ronald Cowan, M.D., Ph.D., associate professor of Psychiatry.

His team reports in the May issue of Neuropsychopharmacology that recreational Ecstasy use is associated with a chronic change in brain function.

“There’s tension in the fields of psychiatry and psychotherapy between those who think Ecstasy could be a valuable therapeutic that’s not being tested because of overblown fears, and those who are concerned about the drug’s potentially harmful effects,” Cowan said.

“We’re not on one side or the other; we’re just trying to find out what’s going on in the brain – is there any evidence for long-lasting changes in the brain?”

The message in news reports needs to be accurate, Cowan said. His team’s studies suggest that the current message should be: “If you use Ecstasy recreationally, the more you use, the more brain changes you get.”

Cowan and his colleagues examined brain activation during visual stimulation, using functional magnetic resonance imaging (fMRI), in subjects who had previously used Ecstasy (but not in the two weeks prior to imaging) and in subjects who had not previously used Ecstasy.

They found increased brain activation in three brain areas associated with visual processing in Ecstasy users with the highest lifetime exposure to the drug. The findings were consistent with the investigators’ predictions based on results from animal models: that Ecstasy use is associated with a loss of serotonin signaling, which leads to hyper-excitability (increased activation) in the brain.

The hyper-excitability suggests a loss in brain efficiency, Cowan said, “meaning that it takes more brain area to process information or perform a task.”

The investigators found that this shift in brain excitability did not return to normal in subjects who had not used Ecstasy in more than a year.

“We think this shift in cortical excitability may be chronic, long-lasting, and even permanent, which is a real worry,” Cowan said, noting that the Ecstasy users in the study are young (18 to 35 years old). “The question is what will happen to their brains as they age over the next 60 years.”

Cowan said that the pattern of hyper-excitability is similar to that observed in fMRI studies of individuals at risk for, or with early, Alzheimer’s disease.

“I’m not saying that these people are at increased risk for dementia, but that there’s a loss of brain efficiency in both recreational Ecstasy use and early Alzheimer’s.”

The findings suggest that brain hyper-excitability (increased activation in fMRI scans) may be a useful biomarker for Ecstasy-induced neurotoxicity, which the investigators will continue to study.

“Our goal is to be able to let people know whether or not the drug is causing long-term brain damage,” Cowan said. “That’s really critical because millions of people are using it.”

The 2009 National Survey on Drug Use and Health estimated that 14.2 million individuals 12 years or older in the United States had used Ecstasy in their lifetime; 760,000 people had used Ecstasy in the month prior to being surveyed.

Cowan is also interested in determining the doses of Ecstasy that are toxic, and whether there are genetic vulnerabilities to toxicity. If clinical trials show that the drug has therapeutic benefits, it’s critical to know the risks, he said.