What Impact Have State-Level Laws Had on Marijuana Use?

MedicalResearch.com Interview with:

MedicalResearch.com Interview with: Christine Mauro PhD Assistant Professor Biostatistics Columbia University Medical Center   MedicalResearch.com: What is the background for this study? What are the main findings?  Response:  As of November 2016, 28 states have legalized medical marijuana. Several previous studies have found an increase in use for adults after legalization, but not for adolescents.  We wanted to examine whether these age-specific findings varied by gender.  Consistent with past findings, we found past-month marijuana use did not increase after enactment of medical marijuana laws in men or women ages 12-25. Among people 26+, past-month marijuana use increased for men from 7.0% before to 8.7% after enactment (+1.7%, p<0.001) and for women from 3.1% before to 4.3% after enactment (+1.1%, p=0.013). Daily marijuana use also increased after enactment in this age group for both genders (men: 16.3% to 19.1%, +2.8 %, p=0.014; women: 9.2% to 12.7%, +3.4%, p=0.003). There were no statistically significant increases in past-year Marijuana Use Disorder prevalence for any age or gender group after medical marijuana law enactment.    MedicalResearch.com: What should clinicians and patients take away from your report? Response:  The readers should take away several things.  First, despite men being more likely to use marijuana than women are in all age groups, there were relatively few gender differences in terms of the impact of medical marijuana on marijuana use. Second, we found no evidence of an effect of medical marijuana law enactment in any marijuana use outcome for both men and women aged 12-17.  Lastly, we did see an increase in both past-month use and daily use among past-year users in both men and women aged 26+ after enactment, but no changes in past year marijuana used disorder.    MedicalResearch.com: What recommendations do you have for future research as a result of this study?  Response: Because most states in our sample more recently passed medical marijuana laws, it is possible that not enough time has elapsed to observe meaningful and significant changes in Marijuana Use Disorder. Given the impact Marijuana Use Disorder may have on individuals, families, and society, the prevalence of Marijuana Use Disorder should continue to be monitored regularly.   Second, there is considerable variation across provisions included in different states’ medical marijuana laws; some aspects, such as allowances on home cultivation or dispensaries, might have a role in changes in several health outcome indicators.  In addition, eight states have now legalized recreational marijuana, which may also have an impact on marijuana use outcomes over time. Future analyses should account for this variability in marijuana related policies.   MedicalResearch.com: Is there anything else you would like to add? Response: As marijuana use becomes more prevalent, monitoring state-wide trends in marijuana use by age and gender is important for public health planning. In particular, efforts to prevent and limit injury that may be associated with specific activities, such as driving, may be needed as daily marijuana use increases among adults. Downstream effects, either positive or negative, of a growing proportion of the adult population reporting daily marijuana use in states with medical marijuana laws warrants further attention. Disclosure: This work was supported by the National Institutes of Health, National Institute on Drug Abuse (grant R01 DA037866 to S. S. Martins).   MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.  Citation: Christine M. Mauro, Paul Newswanger, Julian Santaella-Tenorio, Pia M. Mauro, Hannah Carliner, Silvia S. Martins. Impact of Medical Marijuana Laws on State-Level Marijuana Use by Age and Gender, 2004–2013. Prevention Science, 2017; DOI: 10.1007/s11121-017-0848-3   Note:  Content is Not intended as medical advice.  Please consult your health care provider regarding your specific medical condition and questions.

Dr. Mauro

Christine Mauro PhD
Assistant Professor Biostatistics
Columbia University Medical Center 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: As of November 2016, 28 states have legalized medical marijuana. Several previous studies have found an increase in use for adults after legalization, but not for adolescents.

We wanted to examine whether these age-specific findings varied by gender.  Consistent with past findings, we found past-month marijuana use did not increase after enactment of medical marijuana laws in men or women ages 12-25. Among people 26+, past-month marijuana use increased for men from 7.0% before to 8.7% after enactment (+1.7%, p<0.001) and for women from 3.1% before to 4.3% after enactment (+1.1%, p=0.013). Daily marijuana use also increased after enactment in this age group for both genders (men: 16.3% to 19.1%, +2.8 %, p=0.014; women: 9.2% to 12.7%, +3.4%, p=0.003).

There were no statistically significant increases in past-year Marijuana Use Disorder prevalence for any age or gender group after medical marijuana law enactment.

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Labels of Majority of Online Cannabidiol Extracts Contain Inaccuracies

MedicalResearch.com Interview with:

Dr. Italia V. Rolle, PhD and Dr. Tim McAfee, MD Office on Smoking and Health National Center for Chronic Disease Prevention and Health Promotion CDC

Marijuana plant (Cannabis sativa)

Marcel Bonn-Miller, PhD
Adjunct assistant professor
Department of Psychiatry
Leader of the Substance Abuse and Anxiety Program
U.S. Veterans Affairs Department 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: A 2015 study found that edible cannabis products (e.g., brownies, cookies, drinks) are often mislabeled.  The FDA has also sent warning letters to a handful of companies selling cannabidiol extracts because of inaccurate labeling of content. This led us to conduct a systematic evaluation of the label accuracy of all cannabidiol extracts sold online.  We tested 84 products from 31 different companies.

The primary take-home of this study is that nearly 70 percent of all cannabidiol extracts sold online had over 10% more or less cannabidiol than advertised; 26% of products were over-labeled (less cannabidiol than indicated) and 42% of products were under-labeled (more cannabidiol than indicated).

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Medical Tetrahydrocannabinol May Be Beneficial For Seizures and Chemotherapy Side Effects

MedicalResearch.com Interview with:

Dr. Wong

Dr. Wong

Shane Shucheng Wong, MD
Massachusetts General Hospital
Boston, Massachusetts 

MedicalResearch.com: What is the background for this study?

Response: Medical cannabis is now legal in 29 states and the District of Columbia, and in those areas with active programs, children and adolescents can legally access medical cannabis with certification from their doctor and consent from a parent. This means that doctors and families need to understand what we know and what we don’t yet know about medical cannabis in order to make the best decision for the health of the individual child. Two synthetic cannabinoids – compounds that act on specific receptors in the brain – have been approved for medical use in the U.S., both of which mimic a form of THC (tetrahydrocannabinol), the compound responsible for the “high” of recreational cannabis use. Dronabinol (Marinol) is approved to treat chemotherapy-induced nausea and vomiting in both children and adults, while the pediatric use of nabilone (Cesamet) carries a caution. A third cannabinoid, cannabidiol, is currently in phase 3 trials for treatment of seizures.

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Marijuana Use Linked To Cognitive Impairment In HIV Patients

MedicalResearch.com Interview with:

Richard Saitz, MD, MPH, FACP, DFASAM Department of Community Health Sciences Boston University School of Public Health Clinical Addiction Research and Education (CARE) Unit Section of General Internal Medicine, Department of Medicin Boston University School of Medicine and Boston Medical Center Boston , Massachusetts

Dr. Saitz

Richard Saitz, MD, MPH, FACP, DFASAM
Department of Community Health Sciences
Boston University School of Public Health
Clinical Addiction Research and Education (CARE) Unit
Section of General Internal Medicine, Department of Medicin
Boston University School of Medicine and Boston Medical Center
Boston , Massachusetts

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Many people living with HIV infection use alcohol and other drugs including marijuana. People with HIV infection are also susceptible to cognitive dysfunction from many causes from HIV infection itself to aging.

The main findings were that among people with HIV and substance use disorder, lifetime marijuana and alcohol use were not associated with cognitive dysfunction, likely due to competing risks.  But current marijuana use was associated with cognitive dysfunction.

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Edible Marijuana Preferred By Consumers Due To Lack of Smoke and Convenience

MedicalResearch.com Interview with:

Sheryl Cates RTI International

Sheryl Cates

Sheryl Cates
RTI International
Durham, NC

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: The goal of this research was to provide a better understanding of consumer perceptions of edible marijuana products, including why users prefer edibles relative to other forms of marijuana such as smoking and vaping and concerns regarding the consumption of edibles. This is important as more states legalize the use of recreational marijuana products. With the increasing popularity of edibles, concerns exist that do not exist with other methods of using marijuana, such as smoking or vaping. These concerns include delayed activation time; accidental ingestion, particularly by children and older adults; and dose titration.

The study team conducted eight focus groups (four groups in Denver, Colorado, and four groups in Seattle, Washington) with users of edibles. Most participants preferred edibles to smoking marijuana because there is no smell from smoke and no secondhand smoke. Other reasons participants like edibles included convenience, discreetness, longer-lasting highs, less intense highs, and edibles’ ability to aid in relaxation, reduce anxiety, and alleviate pain more so than smoking marijuana. Concerns and dislikes about edibles included delayed effects, unexpected highs, the unpredictability of the high, and inconsistency of distribution of marijuana in the product. No participants in either location mentioned harmful health effects from consuming edibles as a concern.  Although focus group findings are not generalizable, the findings are useful for helping inform policy makers and regulators as they establish regulations regarding the manufacture, labeling, and sale of edibles.

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Vaporizing Cannabis May Lead To Release Of Benzene Carcinogens

MedicalResearch.com Interview with:

Dr. Italia V. Rolle, PhD and Dr. Tim McAfee, MD Office on Smoking and Health National Center for Chronic Disease Prevention and Health Promotion CDC

Marijuana plant (Cannabis sativa)

Jiries Meehan-Atrash
Department of Chemistry, Portland State University
Portland, Oregon 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: The need for this study stems from the rising popularity of cannabis, and specifically the fact that many consumers are under the belief that vaporizing extracts thereof is safer than smoking. While this may in fact have some truth to it, it is clear that we must assess the safety of vaporization a route of administration.

The main findings are that vaporizing terpenes under dabbing conditions generates some levels of methacrolein (a noxious irritant) at all temperatures that are hot enough to vaporize cannabinoids, but significant levels arise at higher temperatures that are more commonly used.

At the highest temperature used by consumers, significant levels of benzene arise, a compound that is a potent carcinogen and should be avoided at all costs.

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Washington-Oregon Study Shows Frequent Inter-State Diversion of Recreational Marijuana

MedicalResearch.com Interview with:
Benjamin Hansen, Keaton Miller, Caroline Weber

A dried Cannabis bud, typical of what is sold for drug use- Wikipedia image

A dried Cannabis bud, typical of what is sold for drug use- Wikipedia image

Department of Economics
University of Oregon

MedicalResearch.com: What is the background for this study?

Response: Recreational marijuana is now, or will soon be, legally available to 21%
of the United States population. A major concern among policy makers at
all levels of government is the trafficking or “diversion” of marijuana
from states where it is legal to other states. Though significant
measures are in place to prevent large scale drug trafficking by
licensed producers, consumers may easily purchase in one state and
travel to a different state for consumption or re-sale. Though this
policy concern has existed since medical marijuana became available in
the 1990s, the extent of this diversion by consumers has been unknown.

We take advantage of a unique natural experiment in the Pacific
Northwest: Oregon opened a recreational market on October 1, 2015, well
after Washington’s market opened on July 8, 2014. By examining the sales
of Washington retailers along the Washington-Oregon border in the months
before and after Oregon’s market opened, we can measure the extent to
which consumers from Oregon crossed state lines to purchase marijuana in
Washington.

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Heavy Marijuana Use May Harm Kidneys, But More Study Needed

MedicalResearch.com Interview with:

Dr. Julie H. Ishida MD Division of Nephrology, Department of Medicine San Francisco and San Francisco Veterans Affairs Medical Center University of California

Dr. Ishida

Dr. Julie H. Ishida MD
Division of Nephrology, Department of Medicine
San Francisco and San Francisco Veterans Affairs Medical Center
University of California

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Marijuana is becoming increasingly accepted in the United States, and animal studies suggest that marijuana could affect kidney function. However, data in humans are limited to case reports of acute kidney injury related to synthetic cannabinoid use and small cohort studies of relatively short duration.

Among 3,765 participants with normal kidney function in the Coronary Artery Risk Development in Young Adults or CARDIA study, my colleagues and I found that higher marijuana use was associated with lower kidney function at the start of the our study. However, we did not find that marijuana was associated with change in kidney function or albuminuria, which is a sign of kidney damage, over long-term follow-up.

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Chronic Cannabis Users Have Blunted Response To Stress

MedicalResearch.com Interview with:

Carrie Cuttler, Ph.D. Clinical Assistant Professor Washington State University Department of Psychology Pullman, WA, 99164-4820

Dr. Cuttler

Carrie Cuttler, Ph.D.
Clinical Assistant Professor
Washington State University
Department of Psychology
Pullman, WA, 99164-4820

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: One of the most common reasons cannabis users report using cannabis is to cope with stress. In support of this, previous research has shown that acute administration of THC or cannabis dampens affective responses and subjective stress ratings. However, our study is the first to compare the stress response of sober cannabis users to non-users. More specifically, we randomly assigned 42 non-cannabis users and 40 cannabis users (who abstained from using cannabis for at least 12 hours prior to the study) to either a stress or no stress condition. Participants in the stress condition were required to perform multiple trials of placing their hand in ice water and counting backwards from 2043 by 17s. Each time they made an error they were given negative feedback and told to start again. Further, they were being video recorded and their image was displayed in front of them. Participants who were assigned to the no stress condition were simply required to perform multiple trials of placing their hand in lukewarm water and counting from 1 to 25. They were not given feedback or recorded. Participants were asked to rate their level of stress and to provide a saliva sample, from which the stress hormone cortisol was measured.

The results showed that, as expected, non-users in the stress condition had higher cortisol levels and higher self-reported stress than non-users in the no stress condition. In contrast, cannabis users in the stress condition demonstrated the same levels of cortisol as cannabis users in the no stress condition and their increase in self-reported stress was smaller than that of the non-users.

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Regular Adolescent Cannabis Users More Likely To Have Later Problems with Drugs, Alcohol and Tobacco

MedicalResearch.com Interview with:
Dr Michelle Taylor PhD
Senior Research Associate in Epidemiology
MRC Integrative Epidemiology Unit (IEU)
School of Social and Community Medicine
University of Bristol
Bristol UK

MedicalResearch.com: What is the background for this study?

Response: Many previous studies have looked at adolescent cannabis use, however most of these look at use at a single time point, for example whether an individual has ever used cannabis at age 16 years, or how regularly a person uses cannabis at age 18. However, as young people do not initiate use at the same time or follow the same pattern of use, using measures at a single time point does not always tell the whole story.
We used a form of statistical modelling using data taken over the course of adolescence to try and characterise underlying patterns of cannabis use across adolescence. We used data from the Avon Longitudinal Study of Parents and Children which had information on cannabis use at six time points between the ages of 13 and 18 years.

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New Marijuana Laws Associated With Increase in Cannabis-Related Health Problems

MedicalResearch.com Interview with:

Deborah S. Hasin, Ph.D. Professor of Epidemiology Columbia University New York, New York 10032

Dr. Hasin

Deborah S. Hasin, Ph.D.
Professor of Epidemiology
Columbia University
New York, New York 10032

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Among adults, the prevalence of cannabis use and cannabis use disorders has increased in recent years. Concerns have been raised that for various reasons, medical marijuana laws would promote use of cannabis and consequently, cannabis-related consequences.

Many studies show that this didn’t happen among adolescents, but very little was known about the relationship between medical marijuana laws and adults. Using data from three surveys spanning the years 1991-2013, the study findings suggested that medical marijuana laws did play a role in increasing rates of cannabis use and cannabis use disorders.

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Cannabis Exacerbates Schizophrenia Symptoms and Prolongs Recovery

MedicalResearch.com Interview with:
Ian Hamilton

Department of Health Sciences
University of York
York, UK 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: This review looked back over 40 years of research on the links between cannabis and psychosis to examine how knowledge has developed on this issue.

The review found that there is sufficient evidence to suggest a dose response relationship exists in the risk for developing a psychosis that would not have happened if the individual had not been exposed to cannabis. Also for people with schizophrenia cannabis exacerbates their symptoms and prolongs recovery.

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Topical Cannabinoids May Fight Itch and Inflammatory Skin Diseases

MedicalResearch.com Interview with:
Jessica S. Mounessa, BS

University of Colorado School of Medicine
Aurora, Colorado and
Robert Dellavalle, MD, PhD, MSPH
Professor of Dermatology and Public Health
University of Colorado School of Medicine
Colorado School of Public Health
Chief, Dermatology Service
US Department of Veterans Affairs
Eastern Colorado Health Care System
Denver, CO 80220 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: One in 10 adult cannabis users in the U.S. use it for medicinal purposes. Medicinal cannabis is well studied for its uses in chronic pain, anorexia, and nausea. Numerous recent studies have highlighted other medicinal uses for cannabinoids and related compounds.

We conducted a comprehensive review of the literature on the potential role of cannabinoids in conditions affecting the skin.

Our study reveals the potential benefit of topically prepared cannabinoid compounds, especially for pruritus and eczema.  For example, creams containing Palmitoylethanolamide (PEA), which enhances cannabinoid-receptor binding, have been successful in relieving itch both in the literature, and anecdotally in our clinics.

Though not strictly considered an endocannabinoid, as it does not directly bind to CB1 and CB2 receptors, PEA works by enhancing endocannabinoid binding to these receptors.** Furthermore, the majority of the cannabinoid compounds we studied did not contain psychoactive effects.

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Regular Marijuana Use is Costly Healthwise, Especially When Started As Teenager

MedicalResearch.com Interview with:

James McIntosh PhD Economics Department Concordia University Montreal, Quebec, Canada.

Dr. McIntosh

James McIntosh PhD
Economics Department
Concordia University
Montreal, Quebec, Canada.

MedicalResearch.com: What is the background for this study

Response: Marijuana is about to become legal in Canada. Consequently, an analysis of its effects on users is a high priority. This issue has been explored by Canadian researchers to some extent but there are gaps in what is known about the effects of using marijuana. Most of the Canadian studies focus on youth or adolescent use. This is clearly important but adult use is as well. Establishing the link between early usage and the effects of use over an individual’s lifetime was a major objective of the study.
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Medical Cannabis May Be Effective Substitute for Opioids

MedicalResearch.com Interview with:

Philippe Lucas VP, Patient Research & Access, Tilray Graduate Researcher, Centre for Addictions Research of BC

Philippe Lucas

Philippe Lucas
VP, Patient Research & Access, Tilray
Graduate Researcher, Centre for Addictions Research of BC 

MedicalResearch.com: What is the background for this study?

Response: In 2001 Canada become one of the first nations to develop a federally regulated program to allow access to cannabis for medical purposes with the launch of the Marihuana Medical Access Regulations (MMAR). The program has undergone numerous convolutions, culminating in the establishment by Health Canada of the Marihuana for Medical Purposes Regulations (MMPR) in 2014, which was replaced by the Access to Cannabis for Medical Purposes (ACMPR) in 2016.

One of the primary changes in the new program(s) has been to move from a single Licensed Producer (LP) of cannabis to multiple large-scale Licensed Producers. This is the first comprehensive survey of patients enrolled in the MMPR/ACMPR, and with 271 complete responses, it’s the largest survey of federally-authorized medical cannabis patients to date.

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High Achieving Adolescents Less Likely To Smoke, But More Likely to Drink, Use Pot

MedicalResearch.com Interview with:
Dr. James Williams
UCL Medical School
UCL
, London, UK

MedicalResearch.com: What is the background for this study?

Response: Despite a downward trend over the last decade in the usage of particular substances amongst adolescents in the UK, smoking cigarettes, drinking alcohol and smoking cannabis remain prevalent behaviours in this demographic. These risky health behaviours present a large problem in terms of public health due to the immediate and long-term health problems they cause, as well as negative non-health outcomes such as poor educational attainment and reduced employment.

The role of academic ability in determining patterns of substance use is not clear and no study has evaluated academic ability at age 11 in relation to the onset and persistence of all three substances from early to late adolescence and into young adulthood. Our study sought to determine the association between academic ability and the onset and persistence of substance use in adolescence in a representative sample of English school pupils. This would answer for the first time whether ability was associated with ‘experimentation’ in early adolescence or if the association persists into late adolescence.

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Cannabis Use Linked To Early Drinking and Alcohol Problems

MedicalResearch.com Interview with:

Kathleen K. Bucholz, Ph.D. Professor, Department of Psychiatry Washington University School of Medicine St. Louis MO 63110-1547

Dr. Kathleen Bucholz

Kathleen K. Bucholz, Ph.D.
Professor, Department of Psychiatry
Washington University School of Medicine
St. Louis MO 63110-1547

MedicalResearch.com: What is the background for this study?

Response: We know that development of alcohol use disorder progresses through several stages of alcohol use, from beginning to drink, to engaging in problem drinking, and then to developing alcohol use disorder, but we don’t know whether the same factors are associated with each step in this progression. Stage-specific associations have implications for prevention, where targeting certain characteristics might stave off progression to the next level of alcohol involvement, potentially. That is what this particular study set out to investigate.

The data were from nearly 3600 adolescents and young adults, the majority of whom came from families with alcohol use disorder in their relatives. Thus, this sample was enriched with individuals who were at high risk for progressing to more severe stages of alcohol involvement. In studying the associations at each stage, we strengthened our analysis by defining wherever possible variables as risk factors only if they occurred before or at the same age as the particular alcohol stage. For example, we counted cannabis use as a risk factor for starting to drink only if it either preceded or occurred at the same age as taking the first drink. With this definition, we can infer that a particular factor is antecedent and not simply a correlated influence.

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Teens Used More Marijuana Following Change in Recreational Use Law

MedicalResearch.com Interview with:

Magdalena Cerda, DrPH, MPH Vice Chancellor's Chair in Violence Prevention Associate Director, Violence Prevention Research Program UC Davis Violence Prevention Research Program

Dr. Magdalena Cerda

Magdalena Cerda, DrPH, MPH
Vice Chancellor’s Chair in Violence Prevention
Associate Director, Violence Prevention Research Program
UC Davis Violence Prevention Research Program

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: The potential effect of legalizing marijuana for recreational use has been a topic of considerable debate since Washington and Colorado first legalized its use for adults in 2012. Alaska, Oregon and Washington, D.C., followed suit in 2014, and voters in California, Massachusetts and Nevada approved recreational use this past November.

In our study, we examined changes in perceived risk of marijuana use, and in use of marijuana among school-attending adolescents, in Washington and Colorado, following legalization of recreational marijuana use, and compared pre- to post-legalization changes in these two states to changes in the 45 contiguous US states that had not legalized recreational marijuana use.

Marijuana use significantly increased and its perceived harm decreased among eighth- and 10th-graders in Washington state following enactment of recreational marijuana laws. There was no change in use or perceived harm among 12th graders or among similar grades in Colorado.

In particular, the data showed that legalization of recreational marijuana use significantly reduced perceptions of marijuana’s harmfulness by 14 percent and 16 percent among eighth and 10th graders and increased their past-month marijuana use by 2 percent and 4 percent in Washington state but not in Colorado. Among states without legalized marijuana use, the perceived harmfulness also decreased by 5 percent and 7 percent for students in the two grades, but marijuana use decreased by 1.3 percent and .9 percent. Among older adolescents in Washington state and all adolescents surveyed in Colorado, there were no changes in perceived harmfulness or marijuana use in the month after legalization.

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Regular Cannabis Use May Slow Down Visual Processing By Retina

MedicalResearch.com Interview with:
Dr Vincent Laprévote
Praticien Hospitalier (MD, PhD, HDR)
Pôle Hospitalo-Universitaire de Psychiatrie du Grand Nancy
Centre Psychothérapique de Nancy

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: There was evidence in animal studies showing that cannabis use could impact visual processing, but lesser was known in humans.

We showed here an association between regular cannabis use and a delay in the later stage of visual processing in the retina.

MedicalResearch.com: What should readers take away from your report?

Response: Regular cannabis use may slightly slow down the early visual processing.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Response: We have to cautiously verify our result in a larger sample. We also have to explore if this delay is present in further stages of visual processing (i. e. in the brain) and has behavioral consequences. Dr Schwitzer also just begun new researches to verify if this delay is permanent or recedes with cannabis cessation.

MedicalResearch.com: Is there anything else you would like to add?

Response: Importantly, all the participants of this research were regular cannabis users before their participation to the study. We systematically proposed cannabis cessation solutions to the participants.

MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.

Citation:

Schwitzer T, Schwan R, Albuisson E, Giersch A, Lalanne L, Angioi-Duprez K, Laprevote V. Association Between Regular Cannabis Use and Ganglion Cell Dysfunction . JAMA Ophthalmol. Published online December 08, 2016. doi:10.1001/jamaophthalmol.2016.4761

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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Marijuana (Cannabis) Use is Independent Predictor of Broken Heart Syndrome in Younger Men

MedicalResearch.com Interview with:

Amitoj Singh MD Chief Cardiology Fellow St. Luke’s University Health Bethlehem, Pennsylvania

Dr. Amitoj Singh

Amitoj Singh MD
Chief Cardiology Fellow
St. Luke’s University Health
Bethlehem, Pennsylvania

MedicalResearch.com: What is the background for this study?

Response: Marijuana use in steadily increasing and it is the most commonly used illicit drug in the US and worldwide. There has been a recent increase in reports of heart and vascular complications associated with its use. These include Myocardial infarctions, stroke and takotsubo.

We had two questions that we wanted to answer with our study:

a) Is there an association between marijuana use and development of Transient Regional Ventricular Ballooning [TVRB] (aka Stress Cardiomyopathy /Broken Heart Syndrome/ Takotsubo)?

b) If the above is true, what are the differences between Marijuana users (MU) and Non Marijuana Users (NMU) who developed Stress Cardiomyopathy.

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Alcohol and Cannabis Abuse Linked To Increased Risk of Schizophrenia

MedicalResearch.com Interview with:
Dr Stine Mai Nielsen

Copenhagen University Hospital
Mental Health Center Copenhagen
Gentofte, Denmark

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Several studies have tested whether use of substances can cause schizophrenia. However due to methodological limitations in the existing literature, uncertainties still remains. We aimed to investigate the association between several types of substance abuses and the risk of developing schizophrenia later in life. We did a nationwide, prospective cohort study using the detailed Danish registers, which enabled us to address some of the limitations from prior findings. Our cohort consisted of more than 3.13 mio. individuals, that we were able to follow up for more than 104 mio. years at risk. We found that dealing with a substance abuse increased the overall risk of developing schizophrenia by 6 times, with abuse of cannabis and alcohol presenting the highest associations (5 and 3 times increased risk). The risk was found to be significant even 10-15 years prior to a diagnosis of substance abuse.

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Use of Marijuana At Young Age Linked To Functional Brain Abnormalities and Lower IQ

MedicalResearch.com Interview with:

Elizabeth Osuch, M.D. Associate Professor; Rea Chair Department of Psychiatry FEMAP--London Health Sciences Centre London, ON

Dr. Elizabeth Osuch

Elizabeth Osuch, M.D.
Associate Professor; Rea Chair
Department of Psychiatry
FEMAP–London Health Sciences Centre
London, ON   

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: As a researcher and psychiatrist doing clinical work in youth aged 16-25 with mood and anxiety disorders I often see patients who are depressed and believe that using marijuana (MJ) improves their mood.  Yet they remain depressed.  This was the clinical inspiration for this brain imaging study, where we investigated emerging adults with Major Depressive Disorder (MDD).  Subject groups included patients with MDD who did and did not use MJ frequently.  Our results showed that the MDD+MJ group did not have significantly less depression than the MDD alone group, and the brain abnormalities found in MDD were not corrected by MJ use in the MDD+MJ group.  In fact, some of the brain differences were worse with the addition of MJ, while others were just different.

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Medical Marijuana Laws Linked To Lower Opioid-Related Traffic Deaths

MedicalResearch.com Interview with:

June H. Kim Doctoral candidate,Department of Epidemiology Mailman School Public Health Columbia University

June Kim

June H. Kim
Doctoral candidate,Department of Epidemiology
Mailman School Public Health
Columbia University

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: A previous study indicated that states with medical marijuana laws had a reduced rate of opioid overdoses. If this is true, we’d expect to see similar reductions in opioid use associated with these laws. For this study, we used data from the FARS, a national surveillance system that records any crash events on US public roads that result in a fatality. Some states provide uniform testing of the majority of their deceased drivers, year to year. Among these states, we found that there was a lower prevalence of positive opioid toxicology tests among drivers crashing in states with an operational medical marijuana versus drivers crashing in states before a future medical marijuana law is implemented, particularly among drivers aged 21-40.

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SneakGuard™ Designed to Protect Children From Accidental Cannabis Ingestion

MedicalResearch.com Interview with:
Graeme Gordon CEO and Founder at SneakGuard - Home of Safe Responsible StorageGraeme Gordon
CEO and Founder at SneakGuard – Home of Safe Responsible Storage

MedicalResearch.com: What is the background for SneakGuard™?

Response: SneakGuard™ creator and founder, Graeme Gordon recognized the urgent need to keep adventurous young snoopers from unintentionally ingesting cannabis. Founded in 2014, SneakGuard™ is a locking, vacuum and thermally insulated container that provides responsible storage of medications and cannabis, with the passion to protect, save and enhance everyday quality of life. Gordon explains “As a father of a 8 year old I understand how pressing it is for adults to protect children, teens, and even pets from unintended ingestion, so I created a unique storage unit to provide a solution.”

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Cannabis Exposure During Pregnancy Linked To Changes in Brain Development in Childhood

MedicalResearch.com Interview with:
Dr. Hanan El Marroun, PhD
Assistant Professor
Department of Child and Adolescent Psychiatry, Department of Epidemiology
The Generation R Study
Erasmus, The Netherlands

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: The background for the study is that little is known about the potential long-term effects of cannabis exposure during pregnancy on child development.

The main findings are the prenatal cannabis exposure was associated with differences in cortical thickness in childhood.

MedicalResearch.com: What should readers take away from your report?

Response: That our findings suggest an association between prenatal cannabis exposure and cortical thickness in children. However, the results must be carefully interpreted, as there may be other factors involved that we did not take into account. Therefore, further research is needed to explore the causal nature of this association.

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Marijuana Smoke Could Have Similar Effects on Lungs as Tobacco

MedicalResearch.com Interview with:

Stefania I. Papatheodorou, MD, PhD Cyprus International Institute for Environmental and Public Health Limassol, Cyprus

Dr. Stefania Papatheodorou

Stefania I. Papatheodorou, MD, PhD
Cyprus International Institute for Environmental and Public Health
Limassol, Cyprus

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Marijuana is the most commonly used illicit drug in the United States. Despite increasing use and acceptance of marijuana, both medically and recreationally, gaps remain in our knowledge regarding potential health effects.

In this study, we aimed to evaluate associations between recent marijuana use, exhaled Nitric Oxide (eNO) and pulmonary function. We performed a cross-sectional study of 10,327 US adults participating in the National Health and Nutrition Examination Survey (NHANES) in the years 2007 to 2012.

Exhaled Nitric Oxide was lower among participants who used marijuana in the past 0 to 4 days and those who last used marijuana 5 to 30 days before the examination compared with the never users. FEV1 was higher among participants who used marijuana within 0 to 4 days before the examination compared with those who never used marijuana, while FVC was higher in both past and current marijuana users compared with never users. The FEV1/FVC ratio was significantly lower among those who used marijuana in the 0 to 4 days before the examination compared with never users.

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Continued Use of Marijuana in Pregnancy is Risk for Both Mother and Baby

MedicalResearch.com Interview with:

Professor Claire Roberts PhD Professor Claire Roberts Robinson Research Institute Adelaide University

Prof. Claire Roberts


Professor Claire Roberts PhD

Robinson Research Institute
Adelaide University

MedicalResearch.com: What is the background for this study? What are the main findings?

Dr. Roberts: Our research aimed to identify novel risk factors for the four main complications of pregnancy;

  • preeclampsia where the mother gets high blood pressure and her kidneys don’t work properly,
  • preterm birth which is delivery before 37 weeks of gestation,
  • small for gestational age and
  • gestational diabetes.

    We have studied over 5500 pregnant women in 6 centres in 4 countries, Australia, New Zealand, the UK and Ireland. We have identified a number of factors that contribute to these major pregnancy complications. However, in this paper we have focused on well known risk factors for pregnancy complications including maternal cigarette smoking, BMI and socioeconomic status. To these we added maternal use of marijuana before pregnancy, in first trimester, at 15 weeks and at 20 weeks gestation. After adjusting the data for the other factors, we found that continued maternal marijuana use at 20 weeks gestation is strongly associated with spontaneous pre-term birth independent of maternal cigarette smoking. Women who continued to use marijuana at 20 weeks’ gestation were over 5 times more likely to deliver preterm than women who did not use marijuana. Previous studies have shown conflicting evidence but none have accounted for maternal cigarette smoking.

Importantly, not only did continued use of marijuana increase risk for preterm birth but it also made these births 5 weeks earlier on average with a greater number of women delivering very preterm. That is much more dangerous for the baby who inevitably would require admission to a neonatal intensive care unit (NICU). Earlier delivery would be expected to increase the baby’s risk for dying and having long term disabilities.

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Traffic Deaths Related To Cannabis Impaired Drivers Doubled After Legalization

MedicalResearch.com Interview with:

Mr. Brian C. Tefft Senior Research Associate AAA Foundation for Traffic Safety

Mr. Brian Tefft

Mr. Brian C. Tefft
Senior Research Associate
AAA Foundation for Traffic Safety

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: In December 2012, a new law took effect in Washington state that effectively legalized the possession and use of small amounts of marijuana by adults aged 21 years and older for recreational purposes, and also created a legal limit for driving under the influence of marijuana such that having a concentration of 5.00 nanograms or greater of delta-9-tetrahydrocannabinol (THC, the main psychoactive chemical in marijuana) per milliliter of whole blood while driving in the state of Washington is per se driving under the influence.

Data from population-based surveys indicate that the proportion of Washington state residents who report using marijuana increased after this law took effect; however, not much was known about the impact of this new law on traffic safety in the state. To investigate the traffic safety impact of the new law, we examined drug test results from drivers involved in motor vehicle crashes that occurred in years 2010 – 2014 in Washington and resulted in the death of at least one person within 30 days of the crash. Specifically, we looked at the proportion of all drivers involved in fatal crashes who had detectable THC in their blood at or shortly after the time of the crash, which generally suggests that the driver had used marijuana within the past few hours.

Results showed that from 2010 through 2013, approximately 8-9% of drivers in fatal crashes each year were positive for THC, and that proportion was basically flat from 2010 through 2013. In 2014, the proportion basically doubled, to 17%. Our modelling suggests that an increasing trend in the proportion of drivers who were positive for THC began in late 2013, about 9-10 months after the new law took effect.

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Mouse Study Suggests Marijuana May Affect Male Fertility

MedicalResearch.com Interview with:

Paola Grimaldi, PhD Associate Professor of Anatomy Department of Biomedicine and Prevention, School of Medicine, University of Rome Tor Vergata Rome, Italy

Dr. Paola Grimaldi

Paola Grimaldi, PhD
Associate Professor of Anatomy
Department of Biomedicine and Prevention,
School of Medicine, University of Rome Tor Vergata
Rome, Italy

MedicalResearch.com: What is the background for this study? What are the main findings?

Dr. Grimaldi: Our previous studies reported that mouse mitotic germ cells, spermatogonia, express type 2 cannabinoid receptor (CB2) and its stimulation promoted differentiation and meiotic entry of these cells in vitro. In this study we demonstrate that CB2 plays a role of in regulating the correct progression of spermatogenesis in vivo and we found that the use of exogenous agonist or antagonist of this receptor disrupts the normal differentiation of germ cells. This suggests that a basal and finely regulated level of endocannabinoids in male germ cells activate CB2, thus maintaining the homeostasis of spermatogenesis.

Another important novelty of our study is that CB2 activation in developing germ cells determines the appearance of modifications in DNA-bound proteins, which are known to impact on gene expression and inheritance of specific traits in developing germ cells. An exciting idea could be that these modifications might be maintained in the mature spermatozoa and transmitted to the offspring.

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Cannabis During Pregnancy Can Lead To Low Birth Weight Infants

MedicalResearch.com Interview with:

Cara Christ, M.D., M.S. Director of the Arizona Department of Health Services

Dr. Cara Christ

Cara Christ, M.D., M.S.
Director of the Arizona Department of Health Services

MedicalResearch.com: What is the background for this study? What are the main findings?

Dr. Christ: This study was a systematic review. The purpose of a systematic review is to critically assess and summarize the best available research evidence on a specific issue. This usually involves a critical synthesis of the results of several high quality studies on the issue under review. Overall, this review found that infants exposed to cannabis during pregnancy had a 77% higher likelihood of being underweight (<2500grams) at birth, compared to infants whose mothers did not use cannabis. Also, if the mother used cannabis during pregnancy, the likelihood of her infant needing to be placed in a neonatal intensive care unit was two times higher compared to those infants whose mothers did not use cannabis during pregnancy.

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Outcome of Psychosis Better If Patients Stop Cannabis

MedicalResearch.com Interview with:
Dr Sagnik Bhattacharyya
Reader in Translational Neuroscience and Psychiatry
Institute of Psychiatry, Psychology & Neuroscience, KCL
Consultant Psychiatrist, Early Intervention Pathway
Director, Maudsley Early Intervention in Dual Diagnosis clinic
Psychosis Clinical Academic Group, South London & Maudsley NHS Foundation Trust
King’s Health Partners 

MedicalResearch.com: What is the background for this study? What are the main findings?

Dr. Bhattacharyya: Cannabis is the most commonly used illicit drug in the world and its use has been linked to the onset of psychotic disorders such as schizophrenia. Whilst a lot of research has investigated the association between cannabis use and the development of psychosis, there is less clarity regarding the consequences of continued cannabis use in those with an established psychotic disorder. We therefore pooled together all available evidence from studies that specifically looked at the effects of cannabis use on outcome following the onset of psychosis. Based on data from more than 16000 patients with a first episode or more established psychosis, our results show that continued cannabis use is consistently associated with poor outcome in the form of more relapses (as indexed by psychiatric hospitalisation), longer hospitalisations and increased positive symptoms. However, outcomes were not as bad if cannabis use was discontinued following the onset of psychosis.

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Marijuana Use Increases Hospitalizations and Poor Outcomes in Patients With Psychotic Disorders

MedicalResearch.com Interview with:

Dr. Rashmi Patel MA (Cantab) MA BM BCh PGDip (Oxon) MRCPsych Clinical Lecturer in General Psychiatry Kings College London

Dr. Rashmi Patel

Dr. Rashmi Patel MA (Cantab) MA BM BCh PGDip (Oxon) MRCPsych
Clinical Lecturer in General Psychiatry
Kings College London

MedicalResearch.com: What is the background for this study? What are the main findings?

Dr. Patel: Previous studies suggest that cannabis use is associated with an increased risk of developing a psychotic disorder but, until now, little was known about the effects of cannabis on people with an established psychotic disorder. Using novel text mining techniques, we investigated the association of cannabis use with the clinical outcomes of over 2,000 people following their first episode of psychosis.

We found that cannabis use was associated with significantly poorer clinical outcomes including a 50% increased frequency of hospital admission and 35 additional days spent in hospital in the 5 years after first receiving treatment. We also found that the poor outcomes associated with cannabis use may be linked to antipsychotic treatment failure.

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Gene Variant May Predict Cannabis Users At Risk of Psychosis

MedicalResearch.com Interview with:

Prof. Celia Morgan PhD Professor of Psychopharmacology University of Exeter

Prof. Celiai Morgan

Prof. Celia Morgan PhD
Professor of Psychopharmacology
University of Exeter 

Medical Research: What is the background for this study? What are the main findings?

Dr. Morgan: We know cannabis increases the risk of psychosis but it is unclear how we can predict who is vulnerable to these negative effects.

This study suggested that cannabis may have stronger effects in people carrying a particular genetic variant. This might be related to their risk of developing psychosis.

We also found that women are more susceptible to the short term memory impairing effects of cannabis.

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High Potency Skunk Cannabis Alters White Matter of Brain

Dr Silvia Rigucci MD Department of Neurosciences, Mental Health and Sensory Organs Sapienza University of Rome Rome, Italy

Dr. Rigucci

MedicalResearch.com Interview with:
Dr Silvia Rigucci MD

Department of Neurosciences, Mental Health and Sensory Organs
Sapienza University of Rome
Rome, Italy

Medical Research: What is the background for this study? What are the main findings?

Dr Rigucci Nowadays, ‘skunk-like’ products contain more Δ9-tetrahydrocannabinol (THC) than they did around a decade ago and they have been shown to induce psychotic symptoms. Therefore,  exploring the impact of cannabis potency on brain structure is becoming particularly important.

We found that frequent use of high potency cannabis significantly affects the structure of white matter fibers in the brain, independently of the presence of a psychotic disorder. Continue reading

Study Evaluates Cannabis For Pain From Diabetic Neuropathy

Mark S. Wallace MD Department of Anesthesiology School of Medicine University of California, San Diego, CaliforniaMedicalResearch.com Interview with:
Mark S. Wallace MD
Department of Anesthesiology
School of Medicine
University of California, San Diego, California

Medical Research: What is the background for this study? What are the main findings?

Dr. Wallace: The study was funded by the center for medicinal cannabis research at the University of California San Diego.  The center was funded by the state of California.  The center was the first to fund a series of double-blind randomized controlled trials with inhaled cannabis for neuropathic pain.  My trial is the first in diabetic peripheral neuropathy pain which is one of the most prevalent pain syndromes in our society with limited treatments.  We found a dose dependent reduction in pain.  However there was also a dose dependent increase in euphoria and sedation which may limit clinical use.  Effects on neurocognitive functioning were minimal.

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Non-Psychotropic Cannabis Extract May Promote Bone Healing

Yankel Gabet, DMD, PhD Department of Anatomy and Anthropology Sackler Faculty of Medicine, Tel Aviv University Tel Aviv IsraelMedicalResearch.com Interview with:
Yankel Gabet, DMD, PhD
Department of Anatomy and Anthropology
Sackler Faculty of Medicine, Tel Aviv University
Tel Aviv Israel

Medical Research: What is the background for this study? What are the main findings?

Dr. Gabet: Cannabis affects the body via specific components that are able to binding to receptors in the brain and other tissues. The components include the well-known Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), the major constituents of cannabis. The cannabinoid receptors in our body are activated by several molecules (‘endocannabinoids’) synthesized by different sorts of cells under specific conditions. These receptors can be activated by synthetic compounds (cannabinoid ligands) as well as by natural cannabis. The effect of endocannabinoids in bone metabolism has been studied before but this study is the first report on the actions of natural THC and CDB in bone fracture healing. This is particularly important in light of the high incidence of both cannabis use and bone fractures; it is likely that many patients suffering from bone fractures consume cannabis that may have beneficial or adverse effects on the healing process. Another important point is that the non-psychogenic CDB is enough to promote bone healing, so there is no need to be exposed to the euphoric effects of  cannabis/THC to get the beneficial functions of CBD on bone.

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Majority of Medical Cannabis Products Found To Be Mislabeled

Ryan Vandrey, Ph.D. Associate Professor Behavioral Pharmacology Research Unit Johns Hopkins University School of Medicine Baltimore, MD 21224MedicalResearch.com Interview with:
Ryan Vandrey, Ph.D.
Associate Professor
Behavioral Pharmacology Research Unit
Johns Hopkins University School of Medicine
Baltimore, MD 21224

Medical Research: What is the background for this study? What are the main findings?

Dr. Vandrey: The background for the study was that I have had several conversations with individuals that led me to believe that there was insufficient regulation of products of all types being sold in medical cannabis dispensaries.  In order to evaluate that, we needed to do a study.  We decided to test edible products because that is a growing market, and, because it involves some level of manufacturing, there is greater chance for dose variability and inaccuracy.  The main finding was that the majority of products were purchased from retail stores selling cannabis products for medical use were significantly mislabeled with regards to the dose of THC and other cannabinoids.

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Few Well Done Studies Support Medical Use of Cannabis

MedicalResearch.com Interview with:
Penny F. Whiting, PhD
School of Social and Community Medicine, University of Bristol
The National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care West at University Hospitals, Bristol NHS Foundation Trust, Bristol UK
Kleijnen Systematic Reviews Ltd, Escrick, York, United Kingdom

MedicalResearch: What is the background for this study? What are the main findings?

Dr. Whiting: Cannabis is one of the most popular recreational drugs – only tobacco, alcohol and caffeine are more popular. It can result in an alteration to mood and a feeling of “high”. An estimated 141 million people use cannabis worldwide – this is equivalent to 2.5% of the world’s population. Cannabis has a long history of use for the relief of a wide variety of medical symptoms. There is evidence of its use for medical purposes going back to early Egyptian times. The pen-ts’ao ching the world’s oldest herbal book includes reference to cannabis as medicine for rheumatic pain, constipation, disorders of the female reproductive system, and malaria amongst others, this herbal book also contains the first reference to cannabis as a psychoactive drug.  However, its use is controversial as it has been included as a controlled drug in the United Nations Single Convention on Narcotic Drugs since 1961, and the use of cannabis is illegal in most countries.

Medical cannabis (or medical marijuana) refers to the use of cannabis or cannabinoids (any compound, natural or synthetic, that can mimic the actions of plant-derived cannabinoids) as medical therapy to treat disease or alleviate symptoms. Some countries have legalised medicinal-grade cannabis to chronically ill patients but in others its use remains illegal even for medicinal purposes. Canada and the Netherlands have government run programmes where specialised companies supply quality controlled herbal cannabis. These programmes have been running since 2001 and 2003 respectively. In the US around half of the states have introduced laws to permit the medical use of cannabis; other countries have similar laws.

Kleijnen Systematic Reviews Ltd (see below) were commissioned by the Swiss Federal Office of Public Health to conduct a systematic review for the effects and adverse events of medical cannabis to inform policy decision making. Systematic reviews are studies of studies that offer a systematic approach to reviewing and summarising evidence. They follow a defined structure to identify, evaluate and summarise all available evidence addressing a particular research question. We were asked to focus on the following ten indications which were of particular interest to our commissioners: nausea and vomiting due to chemotherapy, patients with HIV/AIDS, chronic pain, spasticity in patients with multiple sclerosis or paraplegia, depression, anxiety disorder, sleep disorder, psychosis, glaucoma, and Tourette’s syndrome. We only included randomised trials, the most robust design for evaluating the effects of an intervention. We included almost 80 trials (nearly 6500 participants). We had most evidence for chronic pain (28 trials), nausea and vomiting due to chemotherapy (28 trials) and spasticity due to MS or paraplegia (14 trials) with less than five studies included for each of the other indications and none for depression.   With the exception of the nausea and vomiting due to chemotherapy population, studies general compared cannabinoids to placebo with only single studies for each indication comparing cannabinoid with an active comparator. In the nausea and vomiting population the majority of studies compared cannabinoids to an active comparator, most commonly prochlorperazine.

Most trials reported greater improvement in symptoms with cannabinoids compared to control groups, however, these did not always reach statistical significance. Cannabinoids were also associated with a greater risk of short term adverse events, including serious adverse events. Common adverse events included dizziness, dry mouth, nausea, fatigue, sleepiness, and euphoria. Overall we found that there was moderate quality evidence to support the use of cannabinoids for the treatment of chronic pain and spasticity and low-quality evidence to suggest that cannabinoids were associated with improvements in nausea and vomiting due to chemotherapy, weight gain in HIV infection, sleep quality, and Tourette syndrome. When determining the quality of the evidence we considered the risk of bias in trials, the consistency of the evidence across the trials, the directness of the evidence (was the trials research question directly applicable to our review question), and the precision of the evidence.

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Cannabis Extracts Enhance Anti-Tumor Radiation Effects

MedicalResearch.com Interview with:
Dr Wai Liu
Senior Research Fellow
St George’s University of London
London,  SW17

Medical Research: What is the background for this study? What are the main findings?

Dr. Liu: It has been known for some time that certain chemicals called cannabinoids that are isolated from the cannabis plant possess anticancer action through the ability to enhance/engage apoptosis and autophagy. These effects are both dependent and independent upon the cognate receptors. These are found at relatively high levels in brain cells. Brain tumors tend to express these at high levels and so we felt these would be good candidates.

The main findings of the current study is the ability that combining the cannabinoids THC and CBD with irradiation can cause a reduction in tumor that is greater than the sum of the individual treatments. That is, when using doses of irradiation or cannabinoids individually, the effects were minimal; however, if they were used simultaneously, the effect was synergistic, and tumor growth was significantly impeded.
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Adolescent Cannabis Use Linked To Young Adult Adverse Outcomes

MedicalResearch.com Interview with:
Edmund Silins PhD, Research Fellow
National Drug and Alcohol Research Centre
UNSW Medicine University of New South Wales
Sydney  Australia

Medical Research: What are the main findings of the study?

Dr. Silins: There were three particularly interesting aspects to the findings.

  • Firstly, we found clear and consistent associations between adolescent cannabis use and the young adult outcomes investigated.
  • Secondly, there was evidence of a dose-response effect such that the more frequently adolescents used cannabis the more likely they were to experience harms later in life.
  • Thirdly, for most outcomes, these associations remained even after taking into account a wide range of other factors which might potentially explain them.

The adverse effects were greatest for daily cannabis users. Specifically, adolescents who were daily cannabis users were, by the age of 25, more than 60% less likely to complete high school or obtain a university degree, seven times more likely to have attempted suicide, 18 times more likely to have been cannabis dependent, and eight times more likely to have used other illicit drugs, than adolescents who had never used the drug.
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Adolsecent Cannabis Use Linked To Increased Later Life Disability

Anna-Karin Danielsson, PhD Project Coordinator Karolinska Institutet Department of Public Health Sciences (PHS) Widerströmska huset| Stockholm, SwedenMedicalResearch.com Interview with:
Anna-Karin Danielsson, PhD
Project Coordinator
Karolinska Institutet
Department of Public Health Sciences (PHS)
Widerströmska huset| Stockholm, Sweden

Medical Research: What are the main findings of the study?

Dr. Danielsson: Smoking cannabis in adolescence increases the risk of adverse social consequences later on in life.
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Cannabis Component May Protect Against Alzheimer’s Disease Progression

Chuanhai Cao Ph.D. Neuroscientist at the Byrd Alzheimer's Institute and the USF College of Pharmacy.MedicalResearch.com Interview with:
Chuanhai Cao Ph.D.
Neuroscientist at the Byrd Alzheimer’s Institute
and the USF College of Pharmacy.

Medical Research: What are the main findings of the study?

Dr. Cao: The major goal of this study was to investigate the effect of Ä9-tetrahydrocannabinol (THC), a major component of marijuana, on Alzheimer’s disease (AD) pathology. THC has long been known to have anti-inflammatory effects, but we were looking to determine whether THC directly affected amyloid beta (Aâ). Aâ aggregation is considered one of the key pathological hallmarks of Alzheimer’s disease. Our study showed that extremely low doses of THC were able to decrease Aâ production, inhibit Aâ aggregation, and enhance mitochondrial function in a cellular model of AD. Decreased levels of amyloid beta, coupled with THC’s inhibitory effect on aggregation may protect against the progression of Alzheimer’s disease.
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Cannabis Further Impairs Functioning In College Students With Psychiatric Disorders

Meesha Ahuja, MD Department of Psychiatry and Human Behavior of the Warren Alpert Medical School of Brown University Young Adult Behavioral Health Program at Rhode Island Hospital Mentors: Laura Whiteley, MD and Larry Brown, MDMedicalResearch.com Interview with:
Meesha Ahuja, MD
Department of Psychiatry and Human Behavior of the
Warren Alpert Medical School of Brown University
Young Adult Behavioral Health Program at Rhode Island Hospital
Mentors: Laura Whiteley, MD and Larry Brown, MD

MedicalResearch: Why did you decided to study this topic?

Dr. Ahuja: Severe mental illness is more common among college students than it was a decade ago, and the number of college students presenting for psychiatric care both on and off campus has dramatically increased. The rates of cannabis use have also been increasing among college students in the United States since the mid-1990s. The concomitant use of cannabis and other substances among general samples in psychiatric treatment has been linked to poorer clinical outcomes including increased hospitalizations, increased symptomatology, poorer treatment adherence, higher treatment resistance. However, before doing this study, there was no research that examined the effect of cannabis and other substance use disorders on the scholastic and general functioning of college students in psychiatric care.

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Cannabis Associated Cardiovascular Complications Increase

Emilie Jouanjus, PharmD, PhD Risques, maladies chroniques et handicaps Facult_e de M_edecine, Guesde, Toulouse 31073, France.MedicalResearch.com Interview with:
Emilie Jouanjus, PharmD, PhD
Risques, maladies chroniques et handicaps
Facult_e de M_edecine,
Guesde, Toulouse 31073, France.

MedicalResearch.com: What are the main findings of the study?

Dr. Jouanjus: Our study emphasizes that cardiovascular complications make up 1.8 percent of cannabis-related health complications reported in France. These were cases of peripheral arteriopathies, and cardiac and cerebrovascular disorders, some of which resulted in the death. These findings conducted us to conclude that marijuana is a possible risk factor for cardiovascular disease in young adults.
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Herbal Cannabis Not Proven Effective For Rheumatic Diseases

Mary-Ann Fitzcharles, MB, ChB, MRCP(UK), FRCP(C) McGill University Health Centre Division of Rheumatology and Alan Edwards Pain Management UnitMedicalResearch.com Interview with:
Mary-Ann Fitzcharles, MB, ChB, MRCP(UK), FRCP(C)
McGill University Health Centre
Division of Rheumatology and Alan Edwards Pain Management Unit


MedicalResearch.com: What are the highlights of your review?

Dr. Fitzcharles: Thank you for your interest in the review article which will shortly be published in Arthritis Care & Research. This was not a research study but rather a review focused towards the use of herbal cannabis for patients with rheumatic diseases.

The essence of our message after a thorough review of the literature is that there is not a single study published regarding efficacy or side effects of herbal cannabis in the rheumatic diseases. It is notable that almost 2 thirds of persons using herbal cannabis for therapeutic reasons report use for musculoskeletal complaints. In the 21st century, we cannot rely upon heresay or anecdote to justify use of a treatment intervention. It is unacceptable to recommend use of a substance without knowledge of concentration of molecules in the product, any knowledge of blood concentrations that might have a positive or negative effect, and formal study in defined patient populations with acceptable endpoint criteria and evidence for short and long term risks.
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Epidemic of Cannabis Related Drugged Driving Fatalities

Joanne E. Brady SM Senior Staff Associate Department of Anesthesiology Doctoral Candidate in Epidemiology Columbia University Medical Center New York, NY 10032MedicalResearch.com Interview with:
Joanne E. Brady SM
Senior Staff Associate
Department of Anesthesiology
Doctoral Candidate in Epidemiology
Columbia University Medical Center
New York, NY 10032
Department of Epidemiology,
Columbia’s Mailman School of Public Health

MedicalResearch.com: What are the main findings of the study?

Answer: The prevalence of non-alcohol drugs detected in fatally injured drivers in the U.S. increased from 17% in 1999 to 28% in 2010.  The increases are largely driven by the tripling in the prevalence of cannabis.
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Cannabis Withdrawal: Nabiximols as an Agonist Replacement Therapy

David J. Allsop, PhD National Cannabis Prevention and Information Centre, National Drug and Alcohol Research Centre, Faculty of Medicine Now with the School of Psychology, University of Sydney, Sydney, AustraliaMedicalResearch.com Interview with:
David J. Allsop, PhD
National Cannabis Prevention and Information Centre, National Drug and Alcohol Research Centre, Faculty of Medicine
Now with the School of Psychology, University of Sydney, Sydney, Australia

MedicalResearch.com: What are the main findings of the study?

Dr. Allsop: We found that administering a botanical preparation of the cannabinoids Tetrahydrocannabidiol (THC – the main psychoactive ingredient in cannabis) and Cannabidiol (a lesser known component of the cannabis plant that
counteracts the psychotogenic effects of THC with anxiolytic properties) to
dependent cannabis smokers during initial abstinence from cannabis
substantially dampened their withdrawal experience. In essence this is akin
to Nicotine Replacement Therapy (NRT) but for cannabis users. It might seem
obvious – sure you give cannabis users a cannabis preparation and they find
it easier to quit – but this is important because it has never been done
before – and we currently have no consensus evidence based medicines to
offer cannabis users who ask for help.
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Cannabis: Heavy Use Associated with Working Memory Deficits

MedicalResearch.com Interview with:
Dr. Matthew J. Smith PhD
Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, 710 N. Lake Shore Drive, 13th Floor, Abbott Hall, Chicago, IL 60611

MedicalResearch.com: What are the main findings of the study?

Dr. Smith: We observed that the shapes of brain structures involved in a working memory brain circuit seemed to collapse inward in a similar fashion among both of the groups that had a history of daily cannabis use. These cannabis-related changes in shape were directly related to the participants’ poor performance on working memory tasks. Some of the shape abnormalities were more severe in the group with schizophrenia and the history of daily cannabis use. We also found that participants with an earlier age of daily cannabis use had more abnormal brain shapes.
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MS Progression: Cannabis Active Ingredient Ineffective

Professor John Zajicek Professor of Clinical Neuroscience, Centre for Clinical Trials & Health Research - Translational & Stratified Medicine (Peninsula Schools of Medicine and DentistrMedicalResearch.com Interview with:
Professor John Zajicek
Professor of Clinical Neuroscience, Centre for Clinical Trials & Health Research – Translational & Stratified Medicine (Peninsula Schools of Medicine and Dentistry)

MedicalResearch.com: What are the main findings of the study?

Prof. Zajicek: Our study investigated whether dronabinol (one of the major active ingredients of cannabis) may slow the progression of multiple sclerosis. We currently have no treatments that are effective in modifying the disease course in people with either primary or secondary MS. We did a clinical trial across the UK involving nearly 500 patients, who were randomly allocated to dronabinol or placebo, and followed them up for three years to look at progression on rates. Overall we failed to find an effect of dronabinol on disease progression,  either clinically (using a variety of clinical measures) or using magnetic resonance imaging (MRI). There was a suggestion of an effect in people with the least disability (who didn’t need a stick to help them walk), and there were no major problems with serious side effects.  However, over all the population that took part in the study also progressed less than we expected, which reduced our chances of finding an effect of treatment. The  study was not designed to investigate an effect on MS-related symptoms (such as pain and muscle stiffness), which have been investigated before.
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