New research sheds light on potentially negative effects of cannabis
March 30, 2020
Science Daily/Washington State University
Coughing fits, anxiety and paranoia are three of the most common adverse reactions to cannabis, according to a recent study by Washington State University researchers.
The researchers surveyed more than 1,500 college students on the type and frequency of adverse reactions they had experienced while using cannabis for their study in the Journal of Cannabis Research. They also collected information on the students' demographics, personality traits, cannabis use patterns and motives for using the drug.
"There's been surprisingly little research on the prevalence or frequency of various adverse reactions to cannabis and almost no research trying to predict who is more likely to experience these types of adverse reactions," said Carrie Cuttler, assistant professor of psychology and an author on the paper. "With the legalization of cannabis in Washington and 10 other states, we thought it would be important to document some of this information so that more novice users would have a better sense of what types of adverse reactions they may experience if they use cannabis."
More than 50% of the study participants reported having experienced coughing fits, anxiety and/or paranoia while using cannabis. On the other end of the spectrum, the three least-common reported reactions were fainting/passing out, non-auditory/visual hallucinations and cold sweats.
The researchers found the most frequently occurring adverse reactions were coughing fits, chest/lung discomfort and body humming, which a subset of the study group reported occurring approximately 30-40% of the time they were using cannabis.
Panic attacks, fainting and vomiting were considered the most distressing of the 26 possible adverse reactions.
"It is worth noting even the most distressing reactions to cannabis were only rated between moderately' and quite distressing," Cuttler said. "This suggests cannabis users do not, in general, find acute adverse reactions to cannabis to be severely distressing."
The least distressing reactions were reported to be body humming, numbness and feeling off balance/unsteady, the researchers found.
The study showed less frequent users are more likely to report negative effects. Additionally, individuals who reported using cannabis to try to fit in with friends, displayed cannabis use disorder symptoms or had anxiety sensitivity -- a tendency to imagine the worse possible outcome -- were more likely to report adverse reactions as well as experiencing a greater amount of distress.
"Interestingly, we didn't find that quantity of use during a single session predicted very much in terms of whether or not a person was going to have a bad reaction," Cuttler said. "It was the people who smoke on a less frequent basis who tend to have these bad experiences more often."
Moving forward, Cuttler hopes the results of the study will be put to use by doctors, medical cannabis distributors and even bud tenders to give people a better idea of what could go wrong when they get high.
"When you get any other kind of medication, there will be a leaflet or a warning printed on the bottle about the drug's potential side effects," Cuttler said. "There really isn't very much out there on this for cannabis, and we think that it is important for people to have access to this kind of information."
https://www.sciencedaily.com/releases/2020/03/200330130543.htm
Early-and-regular cannabis use by youth is associated with alteration in brain circuits that support cognitive control
June 20, 2019
Science Daily/Elsevier
The development of neural circuits in youth, at a particularly important time in their lives, can be heavily influenced by external factors -- specifically the frequent and regular use of cannabis. A new study in the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP), published by Elsevier, reports that alterations in cognitive control -- an ensemble of processes by which the mind governs, regulates and guides behaviors, impulses, and decision-making based on goals are directly affected.
The researchers found that these brain alterations were less intense in individuals who recently stopped using cannabis, which may suggest that the effects of cannabis are more robust in recent users. Additional findings from the study also suggest greater and more persistent alterations in individuals who initiated cannabis use earlier, while the brain is still developing.
"Most adults with problematic substance use now were most likely having problems with drugs and alcohol in adolescence, a developmental period during which the neural circuits underlying cognitive control processes continue to mature," said lead author Marilyn Cyr, PhD. "As such, the adolescent brain may be particularly vulnerable to the effects of substance use, particularly cannabis -- the most commonly used recreational drug by teenagers worldwide," added the postdoctoral scientist in the Division of Child and Adolescent Psychiatry at the New York State Psychiatric Institute, Vagelos College of Physicians & Surgeons, Columbia University, New York.
The findings are based on functional magnetic resonance imaging (fMRI) data acquired from 28 adolescents and young adults (aged 14-23 years) with significant cannabis use and 32 age and sex-matched non-using healthy controls. Participants were scanned during their performance of a Simon Spatial Incompatibility Task, a cognitive control task that requires resolving cognitive conflict to respond accurately.
Compared to their healthy counterparts, the adolescents and young adults with significant cannabis use showed reduced activation in the frontostriatal circuits that support cognitive control and conflict resolution.
The authors also examined the degree to which fluctuations in activity in relation to conflict resolution is synchronized across the different regions comprised in this frontostriatal circuit (that is, to what extent are regions functionally connected with each other). Although circuit connectivity did not differ between cannabis-using and non-using youth, the research team found an association between how early individuals began regularly using cannabis and the extent to which frontostriatal regions were disrupted, suggesting that earlier chronic use may have a larger impact on circuit development than use of later onset.
"The present findings support the mission of the Adolescent Brain and Cognitive Development study, a longitudinal study aimed at understanding the developmental trajectory of brain circuits in relation to cannabis use," said Dr. Cyr. "In addition, these findings are a first step towards identifying brain-based targets for early interventions that reduce addiction behaviors by enhancing self-regulatory capacity.
"Given that substance use and relapse rates are associated with control processes, interventions based on neural stimulation, such as transcranial magnetic stimulation (TMS), and behavioral interventions, such as cognitive training, that specifically target the brain circuits underlying these control processes may be helpful as adjunct intervention strategies to complement standard treatment programs for cannabis use disorder."
https://www.sciencedaily.com/releases/2019/06/190620104858.htm
Depression among young teens linked to cannabis use at 18
Seattle-focused study suggests earlier intervention with depressed youths could reduce rate of cannabis-use disorder
July 17, 2017
Science Daily/University of Washington Health Sciences/UW Medicine
A study looking at the cumulative effects of depression in youth, found that young people with chronic or severe forms of depression were at elevated risk for developing a problem with cannabis in later adolescence.
The study led by UW Medicine researchers interviewed 521 students recruited from four Seattle public middle schools. Researchers used data from annual assessments when students were ages 12-15 and then again when they were 18. The results were published in the journal Addiction.
"The findings suggest that if we can prevent or reduce chronic depression during early adolescence, we may reduce the prevalence of cannabis use disorder," said lead author Isaac Rhew, research assistant professor of psychiatry and behavioral sciences at the University of Washington School of Medicine.
What researchers called "a 1 standard deviation increase" in cumulative depression during early adolescence was associated with a 50 percent higher likelihood of cannabis-use disorder.
According to researchers, during the past decade cannabis has surpassed tobacco with respect to prevalence of use among adolescents. Cannabis and alcohol are the two most commonly used substances among youth in the United States. They pointed to one national study showing increases in prevalence of cannabis use disorder and alcohol use disorder in the United States, especially among young adults.
Longitudinal studies looking at the link between depression and later use of alcohol and cannabis, however, have been mixed. Some show a link. Others don't. But most studies have assessed adolescent depression at a single point in time -- not cumulatively, said the researchers. Further, there have been differences in how substance use has been measured ranging from the initiation of any use to heavier problematic forms of use.
The study oversampled for students with depressive and/or conduct problems. The researchers were surprised to see that the prevalence of cannabis and alcohol use disorder in this study was notably higher than national estimates with 21 percent meeting criteria for cannabis use disorder and 20 percent meeting criteria for alcohol use disorder at age 18.
What effect the easing of marijuana laws in Washington state had on the youth is unclear. Researchers said it would be informative to conduct a similar study in a state with more strict marijuana laws to understand whether the relationship between depression and cannabis misuse would still hold in areas where marijuana may be less accessible.
The age 18 substance abuse assessments occurred between 2007-2010. Washington state legalized medical cannabis in 1998 and its medical cannabis market expanded greatly after 2009 when the federal justice department issued a ruling known as the Ogden Memo. And in 2003, the city of Seattle made cannabis offenses the lowest enforcement priority for police and the city attorney.
https://www.sciencedaily.com/releases/2017/07/170717151031.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
Sex, drugs and estradiol: Why cannabis affects women differently
October 26, 2018
Science Daily/Frontiers
Sex differences in cannabis use are beginning to be explained with the aid of brain studies in animals and humans.
Cannabis use is riding high on a decade-long wave of decriminalization, legalization and unregulated synthetic substitutes. As society examines the impact, an interesting disparity has become apparent: the risks are different in females than in males.
A new review of animal studies says that sex differences in response to cannabis are not just socio-cultural, but biological too. Published in Frontiers in Behavioral Neuroscience, it examines the influence of sex hormones like testosterone, estradiol (estrogen) and progesterone on the endocannabinoid system: networks of brain cells which communicate using the same family of chemicals found in cannabis, called 'cannabinoids'.
Animal studies
"It has been pretty hard to get laboratory animals to self-administer cannabinoids like human cannabis users," says study co-author Dr Liana Fattore, Senior Researcher at the National Research Council of Italy and President of the Mediterranean Society of Neuroscience. "However, animal studies on the effects of sex hormones and anabolic steroids on cannabinoid self-administration behavior have contributed a lot to our current understanding of sex differences in response to cannabis."
So how does cannabis affect men and women differently? Besides genetic background and hormonal fluctuations, the paper highlights a number of important sex differences.
Men are up to four times more likely to try cannabis -- and use higher doses, more frequently.
"Male sex steroids increase risk-taking behavior and suppress the brain's reward system, which could explain why males are more likely to try drugs, including cannabis" explains Fattore. "This is true for both natural male sex steroids like testosterone and synthetic steroids like nandrolone."
But despite lower average cannabis use, women go from first hit to habit faster than men. In fact, men and women differ not only in the prevalence and frequency of cannabis use, pattern and reasons of use, but also in the vulnerability to develop cannabis use disorder.
"Females seem to be more vulnerable, at a neurochemical level, in developing addiction to cannabis," explains Fattore.
"Studies in rats show that the female hormone estradiol affects control of movement, social behavior and filtering of sensory input to the brain -- all targets of drug taking -- via modulation of the endocannabinoid system, whose feedback in turn influences estradiol production.
"Specifically, female rats have different levels of endocannabinoids and more sensitive receptors than males in key brain areas related to these functions, with significant changes along the menstrual cycle.
"As a result, the interactions between the endocannabinoid system and the brain level of dopamine -- the neurotransmitter of "pleasure" and "reward" -- are sex-dependent."
Human impact
The inconsistency of conditions in these studies greatly complicates interpretation of an already complex role of sex hormones in the endocannabinoid system and cannabinoid sensitivity.
"The effects varied according the specific cannabinoid studied, as well as the strain of animals tested and duration of hormone exposure," admits Fattore. However, the human data so far are consistent with the idea that estradiol regulates the female response to cannabinoids. As in animals, human males and females are diverse in their genetic and hormonally driven behaviour and they process information differently, perceive emotions in different ways and are differently vulnerable to develop drug addiction.
"Blood levels of enzymes which break down cannabinoids fluctuate across the human menstrual cycle, and imaging studies show that brain levels of cannabinoid receptors increase with aging in females -- mirroring in each case changes in estradiol levels."
Fattore believes that deepening our understanding of the interactions between cannabinoids and sex steroids is crucial in assessing the impact of increasing cannabis use, and tackling the fallout.
"Gender-tailored detoxification treatments and relapse prevention strategies for patients with cannabis addiction are increasingly requested. Optimizing personalized evidence-based prevention and treatment protocols demands further research on the source of sex disparities in cannabis response."
https://www.sciencedaily.com/releases/2018/10/181026102627.htm
Marijuana may lead non-smokers to cigarettes
Former smokers who use cannabis are also more likely to relapse, and current smokers who use cannabis are less likely to quit
March 27, 2018
Science Daily/Columbia University's Mailman School of Public Health
While cigarette smoking has long been on the decline, marijuana use is on the rise and, disproportionately, marijuana users also smoke cigarettes. A new study by researchers at Columbia University's Mailman School of Public Health and the City University of New York reports that cannabis use was associated with an increased initiation of cigarette smoking among non-cigarette smokers. They also found adults who smoke cigarettes and use cannabis are less likely to quit smoking cigarettes than those who do not use cannabis. Former smokers who use cannabis are also more likely to relapse to cigarette smoking. Results are published online in the Journal of Clinical Psychiatry.
Until now, little was known about the association between cannabis use and smoking cessation or relapse over time in the general adult population.
The analyses were based on data from the National Epidemiologic Survey on Alcohol and Related Conditions in 2001-2002 and 2004-2005, and responses from 34,639 individuals to questions about cannabis use and smoking status.
"Developing a better understanding of the relationship between marijuana use and cigarette use transitions is critical and timely as cigarette smoking remains the leading preventable cause of premature death and disease, and use of cannabis is on the rise in the U.S.," said Renee Goodwin, PhD, in the Department of Epidemiology at the Mailman School of Public Health, and senior author.
The study suggests that marijuana use -- even in the absence of cannabis use disorder (characterized by problematic use of cannabis due to impairment in functioning or difficulty quitting or cutting down on use) -- is associated with increased odds of smoking onset, relapse, and persistence. As cannabis use is much more common than cannabis use disorder, its potential impact on cigarette use in the general community may be greater than estimates based on studies of cannabis use disorder alone, according to the researchers.
An earlier study by Goodwin and colleagues showed that the use of cannabis by cigarette smokers had increased dramatically over the past two decades to the point where smokers are more than 5 times as likely as nonsmokers to use marijuana daily.
Goodwin advises that additional attention to cannabis use in tobacco control efforts and in clinical settings aimed at reducing cigarette smoking and smoking related negative consequences may be warranted. She also points out that understanding the potential links between cannabis use and cigarette initiation in youth is needed given that recent data suggest cannabis use is more common among adolescents than cigarette use.
https://www.sciencedaily.com/releases/2018/03/180327111032.htm
Rates of marijuana use, heavy use, and cannabis use disorder depend on where you live
Increase in marijuana use reported for adults over the age of 26 in states with less regulated medical marijuana programs
June 15, 2017
Science Daily/Columbia University's Mailman School of Public Health
Adult marijuana use rose significantly in states that passed loosely regulated medical marijuana laws (MMLs) according to a new study by Columbia University's Mailman School of Public Health and Columbia University Medical Center. Highest increases were reported among adults ages 26 and over. Little change was found in past-month marijuana use among adolescents or young adults between the ages 18 and 25. The findings are published online in the journal Addiction.
Adults 26 years of age and older living in states with less regulated medical marijuana programs increased past-month marijuana use from 4 percent to 6.59 percent after the laws were enacted. No significant change was found in the prevalence of cannabis use disorder among adolescents or adults after states enacted medical marijuana laws, regardless whether programs were highly regulated or "loose."
Using data from the National Survey of Drug Use and Health from 2004-2013 the researchers analyzed trends over time with particular emphasis on age groups. This included obtaining prevalences of marijuana use outcomes at the state level by year and whether the enacted laws included a highly regulated ("medicalized") or less regulated ("non-medical") program. Participants were classified as having marijuana abuse or dependence based on DSM-IV criteria.
"In addition to the increase in rates of marijuana use among this age group, we found that the magnitude of impact on rates of marijuana use was greatest among heavy users," said Silvia Martins, MD, PhD, professor of Epidemiology at the Mailman School of Public Health, and senior author. Findings showed an annual increase in near-daily users of 2.36 percent.
There remains concern that with the increase in prevalence of marijuana use, especially heavy use, there will be a proportionate increase in the percent of the population meeting diagnostic criteria for cannabis use disorder. "If this is the case, states with non-medical or lax programs may bear the brunt of this increase, especially among adults over age 25," noted Arthur Robin Williams, MD, fellow, Department of Psychiatry at Columbia, and first author of the study.
However, it may be too early to detect trends regarding the prevalence of cannabis use disorder as the time lag between initiation of marijuana use, escalation of use, and meeting diagnostic criteria for the disorder is often several years.
"We believe our current, largely negative findings however cannot definitely rule out impending increases in cannabis use disorder without further study. The effects of changes in marijuana use prevalences might only be reflected with analyses conducted in future years with more data points," said Dr. Martins.
As of the November 2016 election, 28 states and Washington D.C. had legalized the use of marijuana for medical indications through the passage of medical marijuana laws either by voter initiative or legislative action. Additionally, 8 states and Washington D.C. (all of which allow for medical marijuana) have now fully legalized the recreational use of marijuana by adults over age 21. In addition to differing combinations of these laws, states also vary tremendously in regulations guiding their programs and participant eligibility.
Drs. Martins and Williams recommend further investigation of key aspects of regulation that are currently lacking among non-medical programs. These include active physician oversight, requiring participation in state-licensed dispensaries, and the use of state-licensed products as they may have greater influence on individual morbidity and social costs than the mere passage of medical marijuana laws.
"While the United States has entered a new era of marijuana control policy over the past two decades, our findings strongly suggest researchers should not treat all states with medical marijuana laws uniformly," said Dr. Martins.
https://www.sciencedaily.com/releases/2017/06/170615213250.htm