Cannabis linked to bipolar symptoms in young adults

Cannabis use in youth is linked to bipolar symptoms in young adults, finds new research

November 30, 2017

Science Daily/University of Warwick

Cannabis use in youth is linked to bipolar symptoms in young adults, finds new research by the University of Warwick.

Researchers from Warwick Medical School found that adolescent cannabis use is an independent risk factor for future hypomania -- periods of elated mood, over-active and excited behaviour, and reduced need for sleep that are often experienced as part of bipolar disorder, and have a significant impact on day-to-day life.

Led by Dr Steven Marwaha, a clinical academic Psychiatrist, the research analysed data from the Avon Longitudinal Study of Parents and Children and found that teenage cannabis use at least 2-3 times weekly is directly associated with suffering from symptoms of hypomania in later years.

There was a dose response relationship such that any use still increased the risk but less powerfully.

The Warwick research is the first to test the prospective association between adolescent cannabis use and hypomania in early adulthood, whilst controlling for important other factors that might explain this connection (e.g psychotic symptoms).

Cannabis use was also found to mediate the association of both childhood sexual abuse and hypomania, and male gender and hypomania.

The findings suggest frequent adolescent cannabis use is likely to be a suitable target for interventions that may allay the risk of young people developing bipolar disorder.

Commenting on the research, Dr Marwaha said: "Cannabis use in young people is common and associated with psychiatric disorders. However, the prospective link between cannabis use and bipolar disorder symptoms has rarely been investigated.

"Adolescent cannabis use may be an independent risk factor for future hypomania, and the nature of the association suggests a potential causal link. As such it might be a useful target for indicated prevention of hypomania."

Cannabis is one of the most commonly used illegal substances of abuse in western countries. Problematic use in the general population is as high as 9.5% in the United States, while 2.6% of the UK population report having been cannabis dependent in the last year.

https://www.sciencedaily.com/releases/2017/11/171130214932.htm

Cigarette smokers are 10 times more likely to be daily marijuana users

Strongest relationship between cigarette smoking and daily cannabis use is among 12 to 17 year olds, who are 50 times more likely to be daily cannabis users than non-smokers

November 30, 2017

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

Daily marijuana use has been on the rise over the past decade. Now, a new study by researchers at Columbia University's Mailman School of Public Health and the Graduate School of Public Health and Health Policy, City University of New York, found that cigarette smokers are 10 times more likely to use marijuana on a daily basis. Marijuana use occurred nearly exclusively among current cigarette smokers -- daily or non-daily smokers -- compared with former smokers and those who have never smoked. However, even among non-smokers, daily marijuana use is increasing, particularly among youth and female cigarette smokers. The findings are published online in the American Journal of Public Health.

"While we found that daily cannabis use and cigarette smoking were strongly linked among all subgroups, the most finding striking disparity in daily cannabis use was among youths aged 12 to 17 years," said Renee Goodwin, PhD, Department of Epidemiology, Mailman School of Public Health, and principal investigator. "Nearly one-third of youth who smoke cigarettes reported using cannabis every day. In contrast, less than 1 percent of youth who did not use cigarettes reported daily cannabis use. We are not aware of any previous reports illustrating that daily cannabis use in youths occurs nearly exclusively among those who smoke cigarettes."

The researchers analyzed data from 725,010 individuals ages 12 and older in the National Survey on Drug Use and Health for 2002 to 2014 to determine differences in the prevalence of daily cannabis use. They found that an increase in daily cannabis use was significantly higher among nondaily cigarette smokers than among daily smokers and among former smokers than among never smokers.

Individuals who reported smoking fewer than 100 cigarettes in their lifetime were classified as never smokers; those who reported smoking 100 cigarettes or more in their lifetime and at least 1 cigarette within the past 30 days were considered to be current smokers. Those who smoked 1 to 29 days of the past 30 days were categorized as current nondaily smokers, and those who smoked all 30 of the past 30 days as current daily smokers. Individuals who reported smoking 100 cigarettes in their lifetime and no cigarettes in the past 30 days were grouped as former smokers.

Daily cannabis use increased since 2002 among both nondaily smokers (8 percent in 2014 compared with 3 percent in 2002) and daily smokers (9 percent in 2014 versus 5 percent in 2002). The increase in daily cannabis use was faster among non-daily cigarette smokers relative to daily cigarette smokers. Daily cannabis use increased most rapidly among former cigarette smokers (2.80 percent in 2014 versus 0.98 percent in 2002).

"Using marijuana as an alternative substance is viewed as less addictive, less harmful, and carrying less stigma than cigarettes," said Goodwin. "Some clinical data suggest that marijuana lessens the experience of nicotine withdrawal, and people who quit smoking cigarettes might substitute marijuana to lessen their withdrawal symptoms."

The fastest rates of increase of cannabis use overall were among those aged 26 years and older versus aged 12 to 17 years and 18 to 25 years. However, cigarette smokers aged 12 to 17 were 50 times more likely to be daily cannabis users than youth who do not use cigarettes. In 2014, 28 percent of daily cigarette smokers and 13 percent of non-daily cigarette smokers aged 12 to 17 used cannabis daily, suggesting that 40 percent of 12 to 17 year olds who smoke cigarettes used cannabis daily in 2014. Among female cigarette smokers, 4 percent used cannabis daily.

Cigarette smoking remains the leading preventable cause of disease and premature mortality in the United States. There have been substantial declines in smoking prevalence over the past half century in the United States, although the rate of this decline has decelerated in recent years among various groups.

"It is conceivable that this stunted decline in cigarette use is owing, in part, to the substantial increase in daily cannabis use among smokers," observed Goodwin.

"Understanding the degree to which daily cannabis use may be common among cigarette smokers is critical because previous findings suggest that any past month cannabis use is associated with smoking persistence and relapse," noted Goodwin.

https://www.sciencedaily.com/releases/2017/11/171130141037.htm

Synthetic cannabis-like drug reduces sleep apnea

November 28, 2017

Science Daily/Northwestern University

A synthetic cannabis-like drug in a pill was safe and effective in treating obstructive sleep apnea in the first large multi-site study of a drug for apnea funded by the National Institutes of Health. The study was conducted at Northwestern Medicine and the University of Illinois at Chicago (UIC).

There is currently no drug treatment for sleep apnea, a sleep breathing disorder affecting about 30 million individuals in the United States. In sleep apnea, breathing is interrupted, and these pauses can last from a few seconds to minutes and may occur 30 times or more an hour. Untreated apnea raises the risk of heart disease, diabetes, sleepiness, cognitive impairment and a motor vehicle accident.

Participants in the trial had reduced apnea and decreased subjective sleepiness.

The common treatment for sleep apnea is a CPAP (Continuous Positive Airway Pressure) device that delivers air (acting like an air splint) to prevent collapse of the airway and breathing pauses. But adherence to the device can be challenging for many patients, some who simply stop using it.

"There is a tremendous need for effective, new treatments in obstructive sleep apnea," said co-lead study author David W. Carley, the Katherine M. Minnich Endowed Professor Emeritus of Biobehavioral Health Sciences, Medicine and Bioengineering at UIC.

Researchers investigated the effect of dronabinol, a synthetic version of the molecule Delta-9 THC (tetrahydrocannabinol), which is in cannabis, on sleep apnea in a Phase 2 trial. The trial was the largest and longest randomized, controlled trial to test a drug treatment for sleep apnea.

Dronabinol was approved by the Food and Drug Administration more than 25 years ago to treat nausea and vomiting in chemotherapy patients.

Drug targets the brain in new approach

The drug treatment was a new approach in that it targeted the brain rather than the physical problem of collapsing airways. This reflects the new belief that sleep apnea is not just a physical problem but may be caused by multiple factors. One of those is poor regulation of the upper airway muscles by the brain, said co-lead author Dr. Phyllis Zee.

Zee is the Benjamin and Virginia T. Boshes Professor of Neurology at Northwestern University Feinberg School of Medicine and director of the Northwestern Medicine Sleep Disorders Center.

"The CPAP device targets the physical problem but not the cause," Zee said. "The drug targets the brain and nerves that regulate the upper airway muscles. It alters the neurotransmitters from the brain that communicate with the muscles. Better understanding of this will help us develop more effective and personalized treatments for sleep apnea."

While CPAP is highly effective, some patients simply refuse to use the machine. Even people who want to use it often only stick with it for about four hours a night, on average, Carley said.

"So the best they can get is a roughly 50 percent improvement in their apnea," Carley said. "When people take a pill to treat apnea, they are treated for the entire night."

The final version of the paper will be published Dec. 5 in the journal SLEEP.

How the study worked

In the study, 73 adult patients with moderate or severe sleep apnea were divided into three groups. One group was given a low dose of the drug, a second group received a higher dose and the third, a placebo. Participants took the drug once daily before bed for six weeks.

Six weeks of treatment by the highest dose of dronabinol (10 milligrams) was associated with a lower frequency of apneas or hypopneas (overly shallow breathing) during sleep, decreased subjective sleepiness and greater overall treatment satisfaction compared to the placebo group. The severity of their disorder was reduced by 33 percent compared to complete compliance with the mechanical treatment, although complete compliance for the night is rare.

Real marijuana not the same as apnea drug

Can a person simply ingest or smoke marijuana and get the same benefits for sleep apnea?

No, said Zee. "Different types of cannabis have different ingredients," she noted. "The active ingredient may not be exactly the same as what's indicated for sleep apnea."

"Cannabis contains dozens of active ingredients, but we tested just purified delta-9 THC," added Carley.

Larger scale clinical trials are needed to clarify the best approach to cannabinoid therapy in obstructive sleep apnea, the authors said.

UIC has licensed intellectual property related to the experimental drug treatment used in the study to the pharmaceutical company RespireRx.

Researchers have attempted to identify drugs to treat sleep apnea for nearly 35 years, but to no avail, Carley said.

Carley developed the idea that dronabinol might be useful in treating sleep apnea more than 15 years ago. He and colleagues tested the concept in an animal model of apnea, publishing their findings in the journal SLEEP in 2002 and launched a subsequent pilot study in humans in 2007. Those encouraging findings from the small-scale pilot study formed the basis for this multi-center clinical trial led by Carley and Zee.

"By providing a path toward the first viable obstructive sleep apnea drug, our studies could have a major impact on clinical practice," he said.

https://www.sciencedaily.com/releases/2017/11/171128230117.htm

Traditional Amazonian drug linked to improved sense of wellbeing

November 9, 2017

Science Daily/University of Exeter

A psychedelic drug traditionally used in South America improves people's general sense of wellbeing and may offer a treatment for alcoholism and depression, new research suggests.

Ayahuasca, a psychedelic brew often used in the Amazon region, contains dimethyltryptamine (DMT) -- an illegal class A drug in the UK.

Previous research has suggested that psychedelic drugs such as LSD and magic mushrooms can help alcoholics tackle their addiction.

Using Global Drug Survey data from more than 96,000 people worldwide, researchers from the University of Exeter and University College London found that ayahuasca users reported lower problematic alcohol use than people who took LSD or magic mushrooms.

Ayahuasca users also reported higher general wellbeing over the previous 12 months than other respondents in the survey.

"These findings lend some support to the notion that ayahuasca could be an important and powerful tool in treating depression and alcohol use disorders," said lead author Dr Will Lawn, of University College London.

"Recent research has demonstrated ayahuasca's potential as a psychiatric medicine, and our current study provides further evidence that it may be a safe and promising treatment.

"It is important to note that these data are purely observational and do not demonstrate causality.

"Moreover, ayahuasca users in this survey still had an average drinking level which would be considered hazardous. Therefore, randomised controlled trials must be carried out to fully examine ayahuasca's ability to help treat mood and addiction disorders.

"However, this study is notable because it is, to the best of our knowledge, the largest survey of ayahuasca users completed to date."

Ayahuasca -- a blend of the Psychotria Viridis bush and the stems of the Banisteriopsis Caapi vine -- is used by indigenous tribes and religious groups in the Amazon region, as well as many visitors.

The online survey, which was promoted via social media, measured wellbeing using the Personal Wellbeing Index -- a tool used by researchers around the world which asks about things such as personal relationships, connection with the community and a sense of achievement.

Of the respondents, 527 were ayahuasca users, 18,138 used LSD or magic mushrooms and 78,236 did not take psychedelic drugs.

Senior author Professor Celia Morgan, of the University of Exeter, said: "If ayahuasca is to represent an important treatment, it is critical that its short and long-term effects are investigated, and safety established.

"Several observational studies have examined the long-term effects of regular ayahuasca use in the religious context.

"In this work, long-term ayahuasca use has not been found to impact on cognitive ability, produce addiction or worsen mental health problems.

"In fact, some of these observational studies suggest that ayahuasca use is associated with less problematic alcohol and drug use, and better mental health and cognitive functioning."

However, the survey data showed a higher incidence of lifetime mental illness diagnoses within the ayahuasca users. Subsequent analyses found that these were confined to users from countries without a tradition of ayahuasca use.

The researchers said future studies should examine the relationships between ayahuasca use, mental health, wellbeing and problematic alcohol and substance use among these people.

The survey also asked people about the experiences of ayahuasca, and most users said they took the drug with a healer or a shaman.

Ayahuasca was rated as less pleasant and with less of an urge to use more of it than LSD or magic mushrooms. Its acute effects usually lasted for six hours, and were most strongly felt one hour after consumption.

The paper, published in the Nature journal Scientific Reports, is entitled: "Well-being, problematic alcohol consumption and acute subjective drug effects in past-year ayahuasca users: a large, international, self-selecting online survey."

https://www.sciencedaily.com/releases/2017/11/171109093134.htm

Can cannabinoids be used to treat cancer?

November 6, 2017

Science Daily/Mary Ann Liebert, Inc./Genetic Engineering News

When cannabinoids activate signaling pathways in cancer cells they can stimulate a cell death mechanism called apoptosis, unleashing a potent anti-tumor effect. Yet cannabinoids, which have also shown strong activity against human tumor tissue grown in animal models, have undergone minimal testing in patients. Their potential use as antitumor drugs and/or to boost the effectiveness of conventional cancer therapies is examined in an article published in The Journal of Alternative and Complementary Medicine (JACM).

In "A Review of the Therapeutic Antitumor Potential of Cannabinoids," scientists present the results of a detailed survey of the medical and scientific literature focused on the effects of cannabinoids on signaling pathways involved in tumor cell proliferation and death. The researchers review the mechanisms of anticancer activity of cannabinoids, discuss the similarities and differences between exogenous (plant-derived) and endogenous cannabinoids, report on the clinical studies conducted to date to assess the anti-tumor effects of these compounds, and consider the possible adjuvant properties of cannabinoids in cancer treatment.

"Although medical cannabis is well-supported in the literature for symptom reduction from cancer treatment or the disease itself, there are many claims that cannabis can treat cancer itself," says Leslie Mendoza Temple, MD, ABOIM, University of Chicago Pritzker School of Medicine and Medical Director, Integrative Medicine Program. "So far, this is based on only a handful of small human studies, anecdote, or laboratory research. This article nicely summarizes some of the work done in the lab for an understanding of cannabis' potential anti-cancer mechanisms, while pointing to the paucity of human trials." Dr. Temple adds, "Federal rescheduling of cannabis is critical so we can study its effects in humans and determine cannabis' direct or indirect effects on cancer cells."

https://www.sciencedaily.com/releases/2017/11/171106121300.htm

Nearly 70 percent of cannabidiol extracts sold online are mislabeled

Mislabeling may lead to adverse effects for patients, including children with epilepsy

November 7, 2017

Science Daily/University of Pennsylvania School of Medicine

In recent years, there has been an increased interest in the medicinal use of Cannabidiol (CBD), a chemical that naturally occurs the in cannabis plant (aka "marijuana"). There is interest in CBD as a medicine because there is some evidence that it has medical benefits, but it does not make people feel "high" and there is no indication that CBD, by itself, is abused. Recent research has shown potential therapeutic effects of CBD for young children with rare seizure disorders, and patients in states where cannabis or CBD have been legalized report using it for a variety of health conditions. Business experts estimate that the market for CBD products will grow to more than $2 billion in consumer sales within the next three years. While interest in this area continues to grow, little has been done to ensure regulation and oversight of the sale of products containing CBD. The primary reason for this is that CBD is currently classified as a Schedule I controlled dangerous substance by the DEA, despite having been legalized for medicinal use in many states. Thus, many people do not have access to stores that sell CBD products and instead rely on online retailers to purchase CBD products.

A new study by a Penn Medicine researcher, published this week in JAMA, found that nearly 70 percent of all cannabidiol products sold online are either over or under labeled, causing potential serious harm to its consumers. Marcel Bonn-Miller, PhD, an adjunct assistant professor of Psychology in Psychiatry and the lead author on the study, believes the mislabeling of cannabidiol products is a direct result of inadequate regulation and oversight.

"The big problem, with this being something that is not federally legal, is that the needed quality assurance oversight from the Food and Drug Administration is not available. There are currently no standards for producing, testing, or labeling these oils," Bonn-Miller said. "So, right now, if you buy a Hershey bar, you know it has been checked over; you know how many calories are in it, you know it has chocolate as an ingredient, you know how much chocolate is in there. Selling these oils without oversight, there is no way to know what is actually in the bottle. It's crazy to have less oversight and information about a product being widely used for medicinal purposes, especially in very ill children, than a Hershey bar."

For a month, Bonn-Miller and his team of researchers conducted internet searches to identify and purchase CBD products available for online retail purchase that included CBD content on the packaging. The team purchased and analyzed 84 products from 31 different companies and found that more than 42 percent of products were under-labeled, meaning that the product contained a higher concentration of CBD than indicated. Another 26 percent of products purchased were over-labeled, meaning the product contained a lower concentration of CBD than indicated. Only 30 percent of CBD products purchased contained an actual CBD content that was within 10% of the amount listed on the product label. While studies have not shown that too much CBD can be harmful, products containing either too little or too much CBD than labeled could negate potential clinical benefit to patients. Further, the variability across products may make it troublesome for patients to get a reliable effect.

"People are using this as medicine for many conditions (anxiety, inflammation, pain, epilepsy)," Bonn-Miller explained. "The biggest implication is that many of these patients may not be getting the proper dosage; they're either not getting enough for it to be effective or they're getting too much."

According to Bonn-Miller, a number of products also contained a significant amount of THC -- the chemical compound in cannabis responsible for making a person feel "high" -- which has been shown cause cognitive impairment and other adverse health effects. "This is a medication that is often used for children with epilepsy, so parents could be giving their child THC without even knowing it," he said.

In a previous study, Bonn-Miller and colleagues analyzed cannabinoid dose and label accuracy in edible medical cannabis products and found similar discrepancies. He hopes this and future studies will call attention to the impact of inconsistent cannabis product labelling.

"Future research should be focused on making sure people are paying attention to this issue and encouraging regulation in this rapidly expanding industry."

https://www.sciencedaily.com/releases/2017/11/171107112244.htm

Marijuana use associated with cognitive dysfunction in people with HIV who have substance abuse disorder

November 1, 2017

Science Daily/Boston University School of Medicine

Marijuana use is associated with cognitive dysfunction in people with HIV infection who have an alcohol or other drug use disorder, according to a new study from researchers at Boston University School of Public Health (BUSPH), Boston University School of Medicine (BUSM), and Boston Medical Center (BMC).

While researchers did not detect effects of lifetime cumulative exposure, the study, published in Substance Abuse, showed that more frequent current marijuana use was associated with a measure of cognitive dysfunction on the Medical Outcomes Study HIV Health Survey cognitive function scale.

"People with HIV infection have many reasons to have cognitive dysfunction, from the virus itself to medications for HIV infection and related conditions, particularly as they age," said co-author Richard Saitz, professor and chair of community health sciences at BUSPH, who served as principal investigator on the study. "They also have symptoms like chronic pain and mental health symptoms, and use of marijuana, medically or recreationally, may seem like an option to consider. But at least among people with substance use disorders, it appears to have detrimental effects on cognitive function."

Substance use and substance use disorder are disproportionally common among people living with HIV (PLWH) -- estimated at 40 percent to 74 percent. As PLWH are successfully treated for their infections and are now getting older, information about how alcohol and marijuana might affect their symptoms and physical function is critical to their continued health. Aging with HIV infection is associated with many of the same comorbid health conditions that occur in people without HIV infection. These include cardiovascular diseases and dementia, both of which can be affected by substance use.

"Few, if any, studies have examined the combined effects that alcohol use and marijuana use may have on cognition in PLWH," the authors wrote. "Such an understanding could contribute to efforts to reduce harmful substance use and prevent clinical consequences, particularly in an era in which 'moderate' drinking is at times discussed in terms of possible beneficial effects, and in which marijuana is discussed as a relatively safe and even therapeutic substance."

The researchers conducted cross-sectional regression analyses on 215 HIV-infected adults diagnosed with substance disorder, based on the current Diagnostic and Statistical Manual of Mental Disorders (fourth edition). Participants were part of the Boston Alcohol Research Collaboration on HIV/AIDS cohort, 18 years or older, and had current alcohol or other drug dependence. The study included measures of both current and lifetime alcohol and marijuana use.

There were no effects detected of alcohol or past marijuana exposure on cognitive function, nor did there appear to be any evidence for synergistic effects on cognition. Furthermore, neither alcohol nor marijuana appeared to affect simple tests of memory or attention. The authors postulated that such effects were not detected, even though they are expected at the least with heavy alcohol use, because of multiple other exposures and comorbid health conditions that participants had.

The study was led by Sara Lorkiewicz, who earned her Master of Medical Science at BUSM and is currently a doctoral student at Palo Alto University. The other authors were: Alicia Ventura, director of operations and special projects at BMC; Timothy Heeren, professor of biostatistics at BUSPH; Michael R. Winter, associate director of the Data Coordinating Center at BUSPH; Alexander Y. Walley, associate professor of medicine at Boston University; Meg Sullivan, clinical director of HIV services at Boston Medical Center; and Jeffrey Samet, professor of community health sciences at BUSPH.

https://www.sciencedaily.com/releases/2017/11/171101151215.htm

Marijuana farming hurts environment

October 31, 2017

Science Daily/Ithaca College

Planting cannabis for commercial production in remote locations is creating forest fragmentation, stream modification, soil erosion and landslides. Without land-use policies to limit its environmental footprint, the impacts of cannabis farming could get worse, according to a new study published in the November issue of Frontiers in Ecology and the Environment.

Earlier studies have shown that cannabis production causes environmental damage, including rodenticide poisoning of forest mammals and dewatering of streams due to improper irrigation.

Cannabis, as either a medicinal or recreational drug, is now legal in more than 30 U.S. states and in several countries. In California, where medicinal marijuana has been legal since 1996, voters in November approved the sale and possession of one ounce of marijuana for recreational use. As a result, cannabis production is ramping up.

"Cannabis leaves a small spatial footprint but has potentially significant environmental impacts," said co-author Jake Brenner, associate professor in the Department of Environmental Studies and Sciences at Ithaca College. "To mitigate these impacts, policymakers and planners need to enact specific environmental and land-use regulations to control cannabis crop expansion during this early stage in its development."

Scale matters Effective policymaking for a new crop can be challenging without scientific data. In this study, Brenner, along with Van Butsic, a University of California Cooperative Extension specialist in UC Agriculture and Natural Resources and the UC Berkeley Department of Environmental Science, Policy and Management, and Ian J. Wang, assistant professor in the UC Berkeley Department of Environmental Science, Policy and Management, present an approach for early assessment of landscape changes resulting from new agricultural activities.

Their approach uses per-unit-area analysis of landscape change. To study forest fragmentation in northern California, the scientists compared the effects of cannabis cultivation to those of timber harvest from 2000 to 2013 in Humboldt County.

Based on the size, shape and placement of the cannabis grows among 62 randomly selected watersheds, they quantified the impacts relative to those of timber harvest.

"We found that although timber has greater landscape impacts overall, cannabis causes far greater changes in key metrics on a per-unit-area basis," said Butsic.

On a per-unit-area basis, the cannabis grows resulted in 1.5 times more forest loss and 2.5 times greater fragmentation of the landscape, breaking up large, contiguous forest into smaller patches and reducing wildlife habitat.

"The results show how important it is to consider environmental impacts at different scales," said Brenner.

Current California law caps the size of outdoor cannabis production to 1 acre per parcel, to prohibit the development of industrial-scale cannabis operations outdoors. An unintended consequence of this law may be small dispersed cannabis grows that edge out wildlife.

While the long-term effects of cannabis cultivation on the environment are unknown, the researchers concluded that land management and agricultural policy informed by further research may reduce these threats in California and in other states and countries where cannabis production can be regulated.

"Studies like this one have the potential to directly inform local land-use policy and state environmental regulation," said Brenner. "It's exciting to be a part of this research because it is capturing a human-environment phenomenon at the moment of its emergence."

https://www.sciencedaily.com/releases/2017/10/171031202705.htm

Regular marijuana use linked to more sex

October 27, 2017

Science Daily/Stanford University Medical Center

Despite concerns among physicians and scientists that frequent marijuana use may impair sexual desire or performance, the opposite appears more likely to be the case, new research indicates.

The jury's still out on rock 'n' roll. But the link between sex and at least one drug, marijuana, has been confirmed.

A study by investigators at the Stanford University School of Medicine indicates that, despite concerns among physicians and scientists that frequent marijuana use may impair sexual desire or performance, the opposite appears more likely to be the case.

The findings, to be published online Oct. 27 in the Journal of Sexual Medicine, are based on an analysis of more than 50,000 Americans ages 25-45. And they're unambiguous.

"Frequent marijuana use doesn't seem to impair sexual motivation or performance. If anything, it's associated with increased coital frequency," said the study's senior author, Michael Eisenberg, MD, assistant professor of urology. The lead author is Andrew Sun, MD, a resident in urology.

Hint of a causal connection

The study does not establish a causal connection between marijuana use and sexual activity, Eisenberg noted. But the results hint at it, he added. "The overall trend we saw applied to people of both sexes and all races, ages, education levels, income groups and religions, every health status, whether they were married or single and whether or not they had kids."

The study is the first to examine the relationship between marijuana use and frequency of sexual intercourse at the population level in the United States.

"Marijuana use is very common, but its large-scale use and association with sexual frequency hasn't been studied much in a scientific way," Eisenberg said.

According to the National Institute on Drug Abuse, more than 20 million adult Americans are current marijuana users. With the drug's legalization for medical or recreational use in 29 states, that number is climbing. But despite marijuana's growing status as a recreational drug, its status as a procreational drug remains ambiguous: On one hand, there are reports of erectile dysfunction in heavy users, and rigorous studies have found reduced sperm counts in men who smoke it; on the other hand, experiments conducted in animal models and humans indicate that marijuana stimulates activity in brain regions involved in sexual arousal and activity.

Looking at survey responses

To arrive at an accurate determination of marijuana's effect on intercourse frequency, Eisenberg and Sun turned to the National Survey of Family Growth, sponsored by the federal Centers for Disease Control and Prevention. The survey, which provides data pertaining to family structures, sexual practices and childbearing, reflects the overall demographic features of the U.S. population. Originally conducted at regular intervals, the survey is now carried out on an annual basis. It explicitly queries respondents on how many times they've had intercourse with a member of the opposite sex in the past four weeks, and how frequently they've smoked marijuana over the past 12 months.

The investigators compiled answers to those questions for all years since 2002, when the survey first began collecting data on men as well as women. They included data from respondents ages 25-45 and excluded a small percentage (fewer than 3 percent) of respondents who had failed to answer one or more relevant questions.

In all, Eisenberg and Sun obtained data on 28,176 women averaging 29.9 years of age and 22,943 men whose average age was 29.5. They assessed these individuals' self-reported patterns of marijuana use over the previous year and their self-reported frequency of heterosexual intercourse over the previous four weeks.

Some 24.5 percent of men and 14.5 percent of women in the analysis reported having used marijuana, and there was a positive association between the frequency of marijuana use and the frequency of sexual intercourse. This relationship applied to both sexes: Women denying marijuana use in the past year, for example, had sex on average 6.0 times during the previous four weeks, whereas that number was 7.1 for daily pot users. Among men, the corresponding figure was 5.6 for nonusers and 6.9 for daily users.

In other words, pot users are having about 20 percent more sex than pot abstainers, Eisenberg noted.

Positive association is universal

Moreover, Eisenberg said, the positive association between marijuana use and coital frequency was independent of demographic, health, marital or parental status.

In addition, the trend remained even after accounting for subjects' use of other drugs, such as cocaine or alcohol. This, Eisenberg said, suggests that marijuana's positive correlation with sexual activity doesn't merely reflect some general tendency of less-inhibited types, who may be more inclined to use drugs, to also be more likely to have sex. In addition, coital frequency rose steadily with increasing marijuana use, a dose-dependent relationship supporting a possible active role for marijuana in fostering sexual activity.

Nevertheless, Eisenberg cautioned, the study shouldn't be misinterpreted as having proven a causal link. "It doesn't say if you smoke more marijuana, you'll have more sex," he said.

https://www.sciencedaily.com/releases/2017/10/171027085539.htm

A quarter of problematic pot users have anxiety disorders, many since childhood

Regional data also suggest some teens who abuse pot outgrow habit in adulthood

October 24, 2017

Science Daily/Duke University Medical Center

About a quarter of adults whose marijuana use is problematic in early adulthood have anxiety disorders in childhood and late adolescence, according to new data from Duke Health researchers.

The findings, publishing this week in the November issue of the Journal of the American Academy of Child and Adolescent Psychiatry, also shed light on an estimated 4 percent of adults who endured childhood maltreatment and peer bullying without resorting to chronic marijuana abuse, only to develop problems with the drug between the ages of 26 and 30.

"Given that more states may be moving towards legalization of cannabis for medicinal and recreational purposes, this study raises attention about what we anticipate will be the fastest growing demographic of users -- adults," said lead author Sherika Hill, Ph.D., an adjunct faculty associate at the Duke University School of Medicine. "A lot of current interventions and policies in the U.S. are aimed at early adolescent users. We have to start thinking about how we are going to address problematic use that may arise in a growing population of older users."

The findings are based on data from 1,229 participants in the Great Smoky Mountains Study, a long-term study of residents in 11 counties near the Appalachian Mountains in western North Carolina, where Hispanics and Latinos are underrepresented and Native Americans are overrepresented compared to the rest of the U.S.

A cohort of children in the study were enrolled as young as age 9 and have now reached their 30s. From 1993 to 2015, researchers tracked data in numerous areas of interest, including mental health, education, work attainment, and use of drugs and alcohol.

The researchers defined problematic cannabis or marijuana use as daily consumption or a habit that meets diagnostic guidelines for addiction. They tracked participants' patterns of use from the college years (ages 19-21) into adulthood (ages 26-30).

They found more than three-fourths (76.3 percent) of participants didn't use or develop a problem with marijuana during this period.

The remaining quarter developed problems that researchers grouped into three profiles -- those with limited problems, persistent problems and delayed problems.

Limited users (13 percent)

·     Limited problematic users had trouble with marijuana either while in school before age 16 or in their late teens and early 20s, but their habits dropped off as they aged.

·     Researchers were somewhat surprised that this group reported the highest levels of family conflict and instability during childhood as compared to others in the study; these factors are often associated with more drug use.

·     "When this group of children left home, they seemed to do better," Hill said. "They didn't have as many children at a young age, and they went further in their education when they were 19 to 21 compared to those with persistent and delayed profiles."

Persistent users (7 percent)

·     This group had trouble with marijuana beginning as young as 9 years old and their chronic use continued into their late 20s and early 30s, the data showed.

·     Large portions of this group had anxiety disorders in both childhood (27 percent) and at ages 19-21 (23 percent).

·     They had the highest rates of psychiatric disorders and involvement in the criminal justice system, and most said the majority of their friends were drug users, too.

·     "This suggests that a focus on mental health and well-being could go a long way to prevent the most problematic use," Hill said.

Delayed users (4 percent)

·     This was a small but unique group that made it through adolescence and early adulthood without problematic marijuana use, only to become habitual users between ages 26 and 30.

·     Blacks were five times as likely as whites to be delayed problematic users in the late 20s and early 30s after not having trouble with the between the ages 19-21 -- a peak time for most marijuana users.

·     More than half of delayed users were both bullied by peers and mistreated by caregivers as children, yet also had lower rates of anxiety, alcohol use, and other hard drug use compared to persistent users.

·     "What we don't yet understand is how childhood maltreatment didn't prompt earlier problematic use of cannabis between ages 19 and 21 -- how individuals could be resilient to that kind of adverse experience for so long," Hill said. "One theory is that they were somewhat protected by having fewer peers in late adolescence who were substance users, but this is one of the questions we will continue to seek answers for."

https://www.sciencedaily.com/releases/2017/10/171024141720.htm