MDMA users more empathetic than other drug users

February 8, 2019

Science Daily/University of Exeter

Long-term MDMA users have higher levels of empathy than cannabis and other drugs users, new research suggests.

University of Exeter scientists compared the empathy levels of 25 people who used multiple drugs including MDMA, 19 people who used multiple drugs not including MDMA and 23 people who used alcohol only.

Users of MDMA reported feeling much more empathy -- and were better at identifying the emotions of others on a computer task -- than people who took multiple drugs not including MDMA.The other drugs were cannabis, cocaine and ketamine.

MDMA (3,4-Methylenedioxymethamphetamine, also known as ecstasy) is known to increase empathy for a short period, and these findings about longer-term effects could have implications for possible medical uses.

MDMA is a Class A banned drug in the UK and is not currently licensed for any medical use.

Lead author Molly Carlyle, of the University of Exeter, said: "We recruited long-term but mild users (a minimum of ten times), in order to reflect doses that may be used for medical purposes,

"It has been suggested that MDMA, combined with therapy, might be an effective treatment for psychological trauma and alcoholism, but it has previously been suggested that MDMA may cause heightened social distress. Our findings indicate that isn't the casein our study, MDMA users were better able to understand the emotions of others and had better emotional empathy than people using other drugs, and on a similar level to those who only drink alcohol."

The study's 67 participants completed a questionnaire about their own empathy, and took computerised tasks in which they had to identify emotions on the faces of others. They also reported how strongly they felt emotions based on seeing others in emotional states.

The researchers wanted to measure both cognitive empathy (the ability to understand the emotions of others) and emotional empathy (experiencing emotions due to the emotions of others).

The study says:

·     MDMA users reported feeling significantly greater emotional empathy, and computer tasks revealed greater cognitive empathy, compared to people who used multiple drugs not including MDMA (there was little difference between the MDMA group and the alcohol-only group)

·     All participants showed declines in mood and self-esteem in response to social exclusion, but there were no differences between the three groups.

·     The levels of empathy and social pain in MDMA users were consistent with "normal psychosocial functioning."

The findings contradict previous suggestions that long-term MDMA use may cause heightened social distress.

Professor Celia Morgan, senior author of the research, said: "Our study suggests that mild MDMA use is not associated with any problems in how we function socially. Instead, it seems to make people better at empathy when compared to drug users who don't use MDMA, with a suggestion of better empathy compared to alcohol users.

"We cant say whether differences in empathy are due to taking MDMA, or whether there were already differences in the people who use MDMA and those who don't before they started taking the drug. But importantly this study suggests that MDMA may be used safely as a treatment without side effects on these crucial social processes."

The study, published in the Journal of Psychopharmacology, is entitled: "Greater empathy in MDMA users."

https://www.sciencedaily.com/releases/2019/02/190208115247.htm

Traffic fatalities on a high after cannabis legalization

February 5, 2019

Science Daily/Monash University

Legalizing the sale of cannabis for recreational use can lead to a short-term increase in traffic fatalities in legalizing states and their neighboring jurisdictions, new research suggests.

The researchers looked at the number of additional deaths each month after legalisation, and found there was on average one additional traffic fatality per million residents, in comparison to states that had not changed cannabis laws. The increase was temporary, seeming to last for about a year following legalisation. The combined population of affected areas is 27 million people, suggesting an additional 170 deaths in the first six months after legalisation.

But the study reported the spill over effects to be slightly larger in neighbouring states and provinces, particularly those with population centres closest to the border of a legalising state -- possibly because cannabis users were driving interstate to make purchases, before returning under the influence.

It's called 'cannabis tourism', and Monash University's Dr Tyler Lane says there are important implications for both legalising states and their neighbours as prohibitions against cannabis use are lifted globally.

"The effect of cannabis legalisation on traffic fatalities is a growing public health concern," Dr Lane said.

"The results suggest that legalising the sale of cannabis for recreational use can lead to a temporary increase in traffic fatalities in legalising states. This spills over into neighbouring jurisdictions through cross-border sales, trafficking, or cannabis tourists driving back to their state of residence while impaired.

"Our findings suggest that policymakers should consult with neighbouring jurisdictions when liberalising cannabis policy to mitigate any deleterious effects."

Dr Lane said the findings were in contrast to research on medicinal cannabis suggesting it decreases traffic fatalities.

One reason for the difference may be that medicinal users tend to substitute cannabis for other substances, including alcohol, which has a greater effect on impairment. Recreational users are less likely to substitute and more likely to combine alcohol and cannabis, which has a much bigger effect than either in isolation.

https://www.sciencedaily.com/releases/2019/02/190205090524.htm

Cannabinoid compounds may inhibit growth of colon cancer cells

February 6, 2019

Science Daily/Penn State

Medical marijuana has gained attention in recent years for its potential to relieve pain and short-term anxiety and depression. Now, Penn State College of Medicine researchers say some cannabinoid compounds may actually inhibit the growth of colon cancer cells in the lab.

The researchers tested the effects of synthetic cannabinoid compounds on colon cancer cells in an experiment in test tubes. While the compounds most commonly associated with cannabis -- THC and CBD -- showed little to no effect, 10 other compounds were effective at inhibiting cancer cell growth.

Kent Vrana, chair of the Department of Pharmacology at Penn State College of Medicine, said the study -- recently published in Cannabis and Cannabinoid Research -- helped identify compounds that could be tested further to understand their anti-cancer properties.

"Now that we've identified the compounds that we think have this activity, we can take these compounds and start trying to alter them to make them more potent against cancer cells," Vrana said. "And then eventually, we can explore the potential for using these compounds to develop drugs for treating cancer."

Colorectal cancer is one of the most common cancers diagnosed in the United States, according to the National Cancer Institute, with an estimated 140,250 newly diagnosed cases and 50,630 deaths in 2018. While medical cannabis has largely been used in recent years for palliative care, the researchers said some previous studies suggested that certain cannabinoid compounds may have the potential to inhibit or prevent the growth of tumors.

To explore how effective cannabinoids were at reducing the viability of colon cancer cells specifically, the researchers tested how 370 different synthetic cannabinoid compounds affected seven types of human colon cancer cells.

"There are many different ways cells can become cancerous," Vrana said. "Each of the seven cells we tested had a different cause or mutation that led to the cancer, even though they were all colon cells. We didn't want to test these compounds on just one mutation or pathway to cancer."

The researchers incubated the cancer cells in a lab for eight hours before treating them with the cannabinoid compounds for 48 hours. Any compounds that showed signs of reducing the viability of one kind of cancer cell was then used to treat all seven kinds of cells.

After further screening and analysis, the researchers identified 10 compounds that inhibited the growth of almost all seven types of colon cancer types tested. But while the researchers were able to identify these compounds, Vrana said they are still unsure about how exactly the compounds worked to reduce the viability of the cancer cells.

"The 10 compounds we found to be effective fall into three classes, so they're similar to each other but with small changes," Vrana said. "We know how one of them works, which is by inhibiting the division of cells in general. We also found that the most potent and effective compounds don't seem to work through traditional marijuana receptors, although we're not sure of the exact mechanism yet."

Vrana said certain types of cells, like skin and colon cells, are more susceptible to cancers because they divide very frequently: "Every time a cell divides, there's the chance that it will mutate and keep dividing when it shouldn't, which is how cancers can start. So if we block that signal that's telling cancer cells to continue to divide, that could be a way to stop that cancer."

Vrana said that because the other compounds did not seem to be working through traditional cannabinoid signaling pathways, future research will focus on better understanding how the compounds interact with cancer cells and whether researchers can make the compounds more potent and effective.

https://www.sciencedaily.com/releases/2019/02/190206091420.htm

Marijuana smoking linked with higher sperm concentrations

February 5, 2019

Science Daily/Harvard T.H. Chan School of Public Health

Men who have smoked marijuana at some point in their life had significantly higher concentrations of sperm when compared with men who have never smoked marijuana, according to new research led by Harvard T.H. Chan School of Public Health. The study, conducted in the Fertility Clinic at Massachusetts General Hospital, also found that there was no significant difference in sperm concentrations between current and former marijuana smokers.

"These unexpected findings highlight how little we know about the reproductive health effects of marijuana, and in fact of the health effects of marijuana in general," said Jorge Chavarro, associate professor of nutrition and epidemiology at Harvard Chan School. "Our results need to be interpreted with caution and they highlight the need to further study the health effects of marijuana use."

The study will be published on February 5, 2019 in Human Reproduction.

It is estimated that 16.5% of adults in the U.S. use marijuana, and support for legal recreational use of marijuana has increased dramatically in recent years. Understanding the health effects associated with marijuana use is important given the growing perception that it poses few health hazards.

The researchers hypothesized that marijuana smoking would be associated with worse semen quality. Previous studies on marijuana have suggested that it is associated with negative effects on male reproductive health, but most of those studies had focused on animal models or on men with histories of drug abuse.

For this study, researchers collected 1,143 semen samples from 662 men between 2000 and 2017. On average, the men were 36 years old, and most were white and college educated. Additionally, 317 of the participants provided blood samples that were analyzed for reproductive hormones. To gather information on marijuana use among study participants, researchers used a self-reported questionnaire that asked the men a number of questions about their usage, including if they had ever smoked more than two joints or the equivalent amount of marijuana in their life and if they were current marijuana smokers.

Among the participants, 365, or 55%, reported having smoked marijuana at some point. Of those, 44% said they were past marijuana smokers and 11% classified themselves as current smokers.

Analysis of the semen samples showed that men who had smoked marijuana had average sperm concentrations of 62.7 million sperm per milliliter of ejaculate while men who had never smoked marijuana had average concentrations of 45.4 million sperm per milliliter of ejaculate. Only 5% of marijuana smokers had sperm concentrations below 15 million/mL (the World Health Organization's threshold for "normal" levels) compared with 12% of men who had never smoked marijuana.

The study also found that among marijuana smokers, greater use was associated with higher serum testosterone levels.

The researchers cautioned that there are several potential limitations to the findings, including that participants may have underreported marijuana use given its status as an illegal drug for most of the study period. The researchers emphasized that they do not know to what extent these findings may apply to men in the general population as the study population consisted of subfertile men in couples seeking treatment at a fertility center. Additionally, they noted that there are few similar studies to compare their results against.

"Our findings were contrary to what we initially hypothesized. However, they are consistent with two different interpretations, the first being that low levels of marijuana use could benefit sperm production because of its effect on the endocannabinoid system, which is known to play a role in fertility, but those benefits are lost with higher levels of marijuana consumption," said Feiby Nassan, lead author of the study and a postdoctoral research fellow at Harvard Chan School. "An equally plausible interpretation is that our findings could reflect the fact that men with higher testosterone levels are more likely to engage in risk-seeking behaviors, including smoking marijuana."

Other Harvard Chan School study authors included Mariel Arvizu, Lidia Mínguez-Alarcón, Paige Williams, and Russ Hauser.

https://www.sciencedaily.com/releases/2019/02/190205204100.htm

What drives patients to use medical marijuana: Mostly chronic pain

New study seeks to understand whether people are using cannabis for evidence-based reasons

February 4, 2019

Science Daily/Michigan Medicine - University of Michigan

A new study seeks to understand whether people are using medical cannabis for evidence-based reasons.

Slowly but surely, the stigma surrounding marijuana use is losing its grip in the U.S. Since the 1990s, advocates have pushed for a re-evaluation of cannabis (the plant species name often used interchangeably with marijuana) as a viable treatment for a host of ailments. As of 2018, 33 states and the District of Columbia have approved the medical use of cannabis, while 10 states have legalized marijuana for recreational use. Despite this fact, at the federal level, marijuana remains a Schedule 1 drug under the Controlled Substances Act, defined as a drug with no currently accepted medical use and a high potential for abuse.

New research from the University of Michigan, published in the February issue of Health Affairs, takes a deeper dive into state medical marijuana registry data to provide more insight into its use.

"We did this study because we wanted to understand the reasons why people are using cannabis medically, and whether those reasons for use are evidence based," says lead author Kevin Boehnke, Ph.D., research investigator in the department of anesthesiology and the Chronic Pain and Fatigue Research Center.

He and his U-M colleagues Daniel J. Clauw, M.D., a professor of anesthesiology, medicine, and psychiatry and Rebecca L. Haffajee, Ph.D., assistant professor of health management and policy, as well as U-M alum Saurav Gangopadhyay, M.P.H., a consultant at Deloitte, sought out data from states with legalized medical use of marijuana.

To examine patterns of use, the researchers grouped patient-reported qualifying conditions (i.e. the illnesses/medical conditions that allowed a patient to obtain a license) into evidence categories pulled from a recent National Academies of Sciences, Engineering and Medicine report on cannabis and cannabinoids. The report, published in 2017, is a comprehensive review of 10,000 scientific abstracts on the health effects of medical and recreational cannabis use. According to the report, there was conclusive or substantial evidence that chronic pain, nausea and vomiting due to chemotherapy, and multiple sclerosis (MS) spasticity symptoms were improved as a result of cannabis treatment.

Evidence-based relief

One major finding of the Health Affairs paper was the variability of available data. Less than half of the states had data on patient-reported qualifying conditions and only 20 reported data on the number of registered patients. The authors also noted that the number of licensed medical users, with 641,176 registered medical cannabis patients in 2016 and 813,917 in 2017, was likely far lower than the actual number of users.

However, with the available data, they found that the number of medical cannabis patients rose dramatically over time and that the vast majority -- 85.5 percent -- of medical cannabis license holders indicated that they were seeking treatment for an evidence-based condition, with chronic pain accounting for 62.2 percent of all patient-reported qualifying conditions.

"This finding is consistent with the prevalence of chronic pain, which affects an estimated 100 million Americans," the authors state.

This research provides support for legitimate evidence-based use of cannabis that is at direct odds with its current drug schedule status, notes Boehnke. This is especially important as more people look for safer pain management alternatives in light of the current opioid epidemic.

Notes Boehnke, "Since the majority of states in the U.S. have legalized medical cannabis, we should consider how best to adequately regulate cannabis and safely incorporate cannabis into medical practice."

https://www.sciencedaily.com/releases/2019/02/190204172220.htm

Cannabis use disorder: The policy climate matters

January 23, 2019

Science Daily/Columbia University's Mailman School of Public Health

Adolescents and young adults living in states with more liberal policies reported higher average rates of past-year cannabis use than those in states with more conservative policies. However, the rates of cannabis use disorder -- abuse or dependence on the drug -- were significantly lower in states with more liberal policies compared to states with more conservative policies. The study is one of the first to assess the relationship between policy liberalism and health outcomes, and specifically cannabis use-related outcomes.

Adolescents and young adults living in states with more liberal policies reported higher average rates of past-year cannabis use than those in states with more conservative policies, according to a new study conducted at Columbia University Mailman School of Public Health. However, the rates of cannabis use disorder -- abuse or dependence on the drug -- were significantly lower in states with more liberal policies compared to states with more conservative policies, for ages 12 to 17, and marginally lower for ages 26 and older. These results remained significant even when controlling for the presence of medical cannabis laws. This study is one of the first to assess the relationship between policy liberalism and health outcomes, and specifically cannabis use-related outcomes. The findings are published in the International Journal of Drug Policy.

"The majority of existing work has explored the relationship between medical cannabis laws and cannabis outcomes, whereas our results identified important relationships between the state-level policy context as a whole, and cannabis use outcomes," said Morgan Philbin, PhD, assistant professor of Sociomedical Sciences, and first author. "While this research does not suggest that being in a liberal state causes people to use cannabis, or have lower rates of cannabis use disorder, it does highlight how states may differ beyond substance use policies, and how these differences also merit attention."

Using nationally-representative state-level data, the researchers examined the associations between policy liberalism and cannabis use and cannabis use disorder among past year users. Data were obtained for ages 12-17, 18-25, and 26 and older from the 2004-2006 and 2010-2012 National Survey on Drug Use and Health.

Past year cannabis use was consistently higher in liberal compared to conservative states, and remained significantly higher for ages 12-17 and 18-25 after adjusting for medical cannabis law status. As of December 2018, a total of 33 states had approved medical cannabis laws and eight states plus Washington, D.C. had legalized cannabis use.

Prevalence of cannabis use has increased overall since 2007 which has raised concerns about potential negative consequences associated with problematic use, specifically cannabis use disorder. "These latest findings could directly inform policymakers and public health practitioners about the degree to which other broader contextual factors also influence cannabis use patterns in the U.S.," noted Philbin.

States were categorized as liberal, moderate, or conservative based on the 2005 and 2011 State Rank on Policy Liberalism Index, which is based on policy indicators for which liberals and conservatives commonly differ. The Index ranked each state from 1 (most liberal) to 50 (most conservative) based on its policies regulating gun control, abortion access, Temporary Assistance to Needy families, collective bargaining, and tax structure.

Average state-level prevalence of past-year cannabis use by age was lowest for ages 26 and older and highest for ages 18 to 25 throughout the study period. Average prevalence increased for ages 18-25 in liberal states, from 33 percent to 37 percent, and rose marginally in conservative states, from 25 percent to 26 percent. The same pattern of use was observed for ages 26 and over in liberal (8 percent to 10 percent) and conservative (6 percent to 7 percent) states. For ages 12-17, however, past year use did not significantly change from 2004-2006 to 2010-2012 in liberal or conservative states.

In contrast, cannabis use disorder among past-year cannabis users decreased from 2004-2006 to 2010-2012 among those aged 18-25 in conservative states (22 percent to 18 percent) and liberal states (20 percent to 17 percent). Among individuals ages 26 and over, cannabis use disorder among past-year users decreased in liberal states (11 percent to 8 percent). For 12-17 year olds, cannabis use disorder decreased in conservative states (28 percent to 25 percent), though still remained marginally higher than in liberal states (24 percent).

"Our study highlights the need for researchers and public health professionals to distinguish between cannabis use and cannabis use disorder when interacting with patients at the individual level and when developing primary prevention strategies and interventions at the population level," said Silvia Martins, MD, PhD, associate professor of Epidemiology and senior author. "This line of research not only helps identify how state-level policies as a whole impact cannabis use outcomes, but ultimately supports the development of more health-promoting policies."

The work was funded by the National Institutes of Health/National Institute on Drug Abuse (DA037866, DA039804A, DA031099).

Co-authors are Pia Mauro, Julian Santaella-Tenorio, Christine Mauro, and Elizabeth Kinnard, Columbia Mailman School; and Magdalena Cerdá, New York University.

https://www.sciencedaily.com/releases/2019/01/190123091158.htm

Some pregnant women don't believe cannabis is harmful to their fetus

January 21, 2019

Science Daily/University of British Columbia

Up to one-third of pregnant women do not believe cannabis is harmful to their fetus, according to a new review by UBC researchers.

In some cases, women perceived a lack of communication from their health care providers about the risks of cannabis as an indication that the drug is safe to use during pregnancy.

The findings are outlined in a new review, published in the journal Preventive Medicine, in which UBC researchers sought to identify the latest evidence on women's perspectives on the health aspects of cannabis use during pregnancy and post-partum and whether their perceptions influence decision-making about using the drug.

"Our research suggests that, over the past decade, more women seem to be using cannabis during pregnancy than ever before, even though evidence of its safety is limited and conflicting," said lead author Hamideh Bayrampour, assistant professor in the UBC department of family practice and affiliate investigator at BC Children's Hospital Research Institute. "As many jurisdictions around the world, including Canada, legalize cannabis, it's becoming increasingly important for public health officials to understand perceptions of cannabis use and to increase awareness of the health concerns around its use, especially for pregnant women."

For the review, researchers identified six studies, all conducted in the United States, which looked at women's perceptions about cannabis use during pregnancy.

Across the studies, the rate of cannabis use among pregnant women varied considerably. In a large U.S. population-based study, nearly four per cent of women self-reported using cannabis within the past month, while seven per cent self-reported using cannabis within the past year. However, in another study that saw researchers also test hair and urine samples, the rate of cannabis use increased to 28 per cent.

Pregnant cannabis users were more likely to be under the age of 25, unemployed, single or uninsured, African American, and to have low income and education, or use other substances such as tobacco and alcohol. A diagnosis of anxiety or depression was also associated with cannabis use during pregnancy.

As for patterns of use, the researchers found that cannabis use rates were highest during the first trimester (7.4 per cent) and lowest during the third trimester (1.8 per cent). Most pregnant users reported using cannabis to treat nausea early in their pregnancy.

In one study involving 306 pregnant women, 35 per cent reported being cannabis users when they realized they were pregnant. Two-thirds of those women quit after finding out they were pregnant, but among those who continued to use cannabis, half reported using almost daily or twice a week.

When women were asked about their perception of general harm associated with cannabis use, 70 per cent of both pregnant and non-pregnant cannabis users responded that they perceived slight or no risk of harm. In another study, when asked if they believed cannabis is harmful to a baby during pregnancy, 30 per cent of pregnant women responded "no." When women were asked to identify substances most likely to harm the baby during pregnancy, 70 per cent chose alcohol and 16 per cent chose tobacco, while only two per cent chose cannabis.

While research on the health effects of cannabis is limited, some studies have shown an increased risk of problems for pregnant women, including anemia, low birth weight, stillbirth and newborn admission to the neonatal intensive care unit. Due to the risk of potential problems, many professional organizations, including the Society of Obstetricians and Gynaecologists of Canada, recommend women not use cannabis when trying to conceive, during pregnancy and while breastfeeding.

Still, some women reported that not having specific counselling provided about the risks of cannabis use suggest that the drug is safe.

"One of our review findings revealed that some people don't consider cannabis to be a drug," said Bayrampour. "With this in mind, it's especially important for health care providers to ask specific questions about cannabis use during pregnancy and breastfeeding to help spark a productive conversation about the potential health impacts and to help support women in their decision to reduce use and quit."

https://www.sciencedaily.com/releases/2019/01/190121103421.htm

Worrisome statistics around medical cannabis users operating vehicles

More public education and guidelines are needed to increase marijuana users' understanding of cannabis-related driving impairment

January 9, 2019

Science Daily/Michigan Medicine - University of Michigan

More than half of people who take medical cannabis for chronic pain say they've driven under the influence of cannabis within two hours of using it, at least once in the last six months, according to a new survey. One in five of them said they'd driven while 'very high' in the past six months.

One in five of them said they'd driven while 'very high' in the past six months, researchers from the University of Michigan Addiction Center report in the journal Drug & Alcohol Dependence .

Lead author Erin E. Bonar, Ph.D., assistant professor of psychiatry and a practicing clinical psychologist at the U-M Addiction Treatment Services finds the results of a survey of 790 Michigan medical cannabis users troubling.

Hundreds of thousands of Americans have state approval to use medical marijuana, including nearly 270,000 in the state of Michigan, according to Statista, as of May 2018. Michigan is second only to California for the highest number of medical marijuana patients in a state.

Risky driving

Bonar says that when people drive under the influence of marijuana their reaction time and coordination may be slowed down and they could have a harder time reacting to the unexpected. If they are in a risky situation, they could be more likely to be involved in motor vehicle crash, because they would not be able to respond as quickly.

For the study, the team surveyed adults in Michigan who were seeking medical cannabis recertification or a new certification for chronic pain in 2014 and 2015. The researchers asked about respondents' driving habits for the past six months.

Fifty-six percent of participants reported driving within two hours of using cannabis, 51 percent reported they drove while a "little high," and 21 percent reported driving while "very high."

"There is a low perceived risk about driving after using marijuana, but we want people to know that they should ideally wait several hours to operate a vehicle after using cannabis, regardless of whether it is for medical use or not," Bonar said. "The safest strategy is to not drive at all on the day you used marijuana."

There is uncertainty about how marijuana could affect driving for chronic daily users, who might have even longer-lasting effects that linger in their system, Bonar added.

Uncharted territory

To add complexity to the issue, in November Michigan voters approved the use of recreational marijuana in the state. In early December, it became legal under state law for any Michigan resident over the age of 21 to use marijuana inside a private residence, and to grow up to 12 plants for personal use. Retail sales are only allowed for those with medical marijuana cards issued by the state. Marijuana use and possession remains illegal under federal law.

In light of this policy change, Bonar says, all cannabis users need a clear understanding of the side effects of this drug.

"When it comes to driving, we haven't yet figured out the best way to know how impaired marijuana users are at any given time," she says. "With alcohol, you can do some quick math based on the amount you drank, and take an educated guess at your blood alcohol level. For marijuana, an estimate like this would be complicated. It's hard to quantify because there is a lot of variation in marijuana dosing, THC potency, and route of administration. We also don't have specific guidelines yet about when exactly it would be safe to operate a vehicle."

Bonar says the goal of her team's study -- conducted before the passage of the ballot question that resulted in the change in state law -- is to help medical marijuana users to be safer on the roads.

"We believe more research is needed to inform a larger public education effort that will help individuals understand the risks for themselves, and others, of driving while under the influence of cannabis," she says. "It is especially needed during this time of rapid policy change as many states are determining how to manage marijuana legalization. We also need clearer guidelines about marijuana dosing and side effects with an understanding of how individual differences in things like sex and body weight interact as well."

This study was funded by the National Institute on Drug Abuse. The lead project investigator was Mark Ilgen, Ph.D., director of UMATS. Additional study authors include James Cranford, Ph.D., Brooke Arterberry, Ph.D., Maureen Walton, M.P.H., Ph.D., and Kipling M. Bohnert, Ph.D.

https://www.sciencedaily.com/releases/2019/01/190109170635.htm

Increased risk of harm from cannabis across Europe

December 31, 2018

Science Daily/University of Bath

A significant new study shows that cannabis potency has doubled across Europe in the past 11 years.

Cannabis resin and herbal cannabis have significantly increased in potency and in price, according to the first study to investigate changes in cannabis across Europe.

The study, published today (Sunday 30 December) in the journal Addiction by researchers from the University of Bath and King's College London, draws on data collected from across 28 EU Member states, as well as Norway and Turkey by the European Monitoring Centre for Drugs and Drug Addiction.

The findings show that for herbal cannabis, concentrations of delta-9-tetrahydrocannabinol ('THC' -- the main psychoactive constituent of cannabis) increased by a similar amount each year, from 5% in 2006 to 10% in 2016.

For cannabis resin (or hash), THC concentrations were relatively stable from 2006 to 2011 (from 8% to 10%) but then increased rapidly from 2011 to 2016 (from 10% to 17%). The price of cannabis resin also increased, but to a lesser extent than for herbal cannabis.

Lead author Dr Tom Freeman from the Addiction and Mental Health Group within the Department of Psychology at the University of Bath, said: "These findings show that cannabis resin has changed rapidly across Europe, resulting in a more potent and better value product."

Unlike herbal cannabis, cannabis resin typically contains cannabidiol (CBD) in addition to THC. CBD has recently attracted considerable interest due to its potential to treat several medical conditions including childhood epilepsy syndromes, psychosis and anxiety. When present in cannabis, CBD may offset some of the harmful effects of THC such as paranoia and memory impairment.

Cannabis containing higher levels of THC and / or lower levels of CBD has been linked to greater long-term harms such as the development of cannabis dependence, and an increased risk of psychotic illness. New resin production techniques in Morocco and Europe have increased levels of THC, but not CBD.

Dr Freeman added: "CBD has the potential to make cannabis safer, without limiting the positive effects users seek. What we are seeing in Europe is an increase in THC and either stable or decreasing levels of CBD, potentially making cannabis more harmful. These changes in the illicit market are largely hidden from scientific investigation and are difficult to target by policy-makers. An alternative option could be to attempt to control THC and CBD content through regulation."

It is estimated that 24 million people (or 7.2%) of European adults used cannabis in the last year. Across the globe 192 million people use the drug in a variety of markets, ranging from heavily sanctioned prohibition to commercialised legal sale. Cannabis policies are rapidly changing across the globe.

Recreational use is now legalised in Canada and several US states, and medical use is permitted in many more countries, including very recently in the UK.

https://www.sciencedaily.com/releases/2018/12/181231103957.htm

Exposure to cannabis alters the genetic profile of sperm

Whether genetic changes can be reversed or are passed on to children is still unknown

December 19, 2018

Science Daily/Duke University Medical Center

New research suggests men in their child-bearing years should consider how THC could impact their sperm and possibly the children they conceive during periods when they've been using the drug. Much like previous research that has shown tobacco smoke, pesticides, flame retardants and even obesity can alter sperm, the new research shows THC also affects epigenetics, triggering structural and regulatory changes in the DNA of users' sperm.

As legal access to marijuana continues expanding across the U.S., more scientists are studying the effects of its active ingredient, tetrahydrocannabinol (THC), in teens, adults and pregnant women.

New research from Duke Health suggests men in their child-bearing years should also consider how THC could impact their sperm and possibly the children they conceive during periods when they've been using the drug.

Much like previous research that has shown tobacco smoke, pesticides, flame retardants and even obesity can alter sperm, the Duke research shows THC also affects epigenetics, triggering structural and regulatory changes in the DNA of users' sperm.

Experiments in rats and a study with 24 men found that THC appears to target genes in two major cellular pathways and alters DNA methylation, a process essential to normal development.

The researchers do not yet know whether DNA changes triggered by THC are passed to users' children and what effects that could have. Their findings will be published online Dec. 19 in the journal Epigenetics.

"What we have found is that the effects of cannabis use on males and their reproductive health are not completely null, in that there's something about cannabis use that affects the genetic profile in sperm," said Scott Kollins, Ph.D., professor in psychiatry and behavioral sciences at Duke and senior author of the study.

"We don't yet know what that means, but the fact that more and more young males of child-bearing age have legal access to cannabis is something we should be thinking about," Kollins said.

National research has shown a steady decline in the perceived risk of regular marijuana use. This, combined with the demand and wide availability of marijuana bred specifically to yield higher THC content, make this research especially timely, Kollins said.

The study defined regular users as those who smoked marijuana at least weekly for the previous six months. Their sperm were compared to those who had not used marijuana in the past six months and not more than 10 times in their lifetimes.

The higher the concentration of THC in the men's urine, the more pronounced the genetic changes to their sperm were, the authors found.

THC appeared to impact hundreds of different genes in rats and humans, but many of the genes did have something in common -- they were associated with two of the same major cellular pathways, said lead author Susan K. Murphy, Ph.D., associate professor and chief of the Division of Reproductive Sciences in obstetrics and gynecology at Duke.

One of the pathways is involved in helping bodily organs reach their full size; the other involves a large number of genes that regulate growth during development. Both pathways can become dysregulated in some cancers.

"In terms of what it means for the developing child, we just don't know," Murphy said. It's unknown whether sperm affected by THC could be healthy enough to even fertilize an egg and continue its development into an embryo, she said.

The study was a starting point on the epigenetic effects of THC on sperm and is limited by the relatively small number of men involved in the trial, Murphy said. The findings in men also could be confounded by other factors affecting their health, such as their nutrition, sleep, alcohol use and other lifestyle habits.

The Duke team plans to continue its research with larger groups. They intend to study whether changes in sperm are reversed when men stop using marijuana. They also hope to test the umbilical cord blood of babies born to fathers with THC-altered sperm to determine what, if any epigenetic changes, are carried forward to the child.

"We know that there are effects of cannabis use on the regulatory mechanisms in sperm DNA, but we don't know whether they can be transmitted to the next generation," Murphy said.

"In the absence of a larger, definitive study, the best advice would be to assume these changes are going to be there," Murphy said. "We don't know whether they are going to be permanent. I would say, as a precaution, stop using cannabis for at least six months before trying to conceive."

In addition to Kollins and Murphy, study authors include Nilda Itchon-Ramos, Zachary Visco, Zhiqing Huang, Carole Grenier, Rose Schrott, Kelly Acharya, Marie-Helene Boudreau, Thomas M. Price, Douglas J. Raburn, David L. Corcoran, Joseph E. Lucas, John T. Mitchell, F. Joseph McClernon, Marty Cauley, Brandon J. Hall, and Edward D. Levin.

The research was supported by a grant from the John Templeton Foundation.

https://www.sciencedaily.com/releases/2018/12/181219075846.htm