E-cigarettes are not a gateway into smoking

Peer-Reviewed Publication

QUEEN MARY UNIVERSITY OF LONDON

The most comprehensive study to date investigating whether e-cigarettes are a gateway into or out of smoking finds that, at the population level, there is no sign that e-cigarettes and other alternative nicotine delivery products promote smoking.

The study, led by Queen Mary University of London and funded by the National Institute of Health and Care Research (NIHR), also found some evidence that these products compete against cigarettes and so may be speeding up the demise of smoking, but this finding is only tentative and more data are needed to determine the size of this effect.

The study compared the time course of use and sales of electronic cigarettes with that of smoking rates and cigarette sales in countries with historically similar smoking trajectories, but differing current e-cigarette regulations. It compared the United Kingdom and United States with Australia, where sales of nicotine containing e-cigarettes are banned. It also looked at interactions between smoking and nicotine alternatives that are popular in other countries, including the use of oral nicotine pouches in Sweden and products that heat rather than burn tobacco in Japan and South Korea where they are widely used.

The decline in smokers in Australia has been slower than in the UK, and slower than in both the UK and the USA among young people and in lower socioeconomic groups. The decline in cigarette sales has also accelerated faster in the UK than in Australia. The increase in heated tobacco product sales in Japan was accompanied by a significant decrease in cigarette sales.

Researchers note that because people may use both cigarettes and alternative products, prevalence figures for these products overlap, and so longer time periods are needed to determine any effects of exclusive use of the new products on smoking prevalence. They also say that the indications that alternative nicotine products are replacing smoking – especially the size of this effect – need to be confirmed when more data become available. As further prevalence and sales data emerge, the analyses will become more informative.

Professor Peter Hajek, Director of Health and Lifestyle Research Unit, Wolfson Institute of Population Health, Queen Mary University of London, said:

"The results of this study alleviate the concern that access to e-cigarettes and other low-risk nicotine products promote smoking. There is no sign of that, and there are some signs that they in fact compete against cigarettes, but more data over a longer time period are needed to determine the size of this effect."

Co-author, Professor Lion Shahab, Co-Director of the UCL Tobacco and Alcohol Research Group, said:

"This comprehensive analysis provides reassurance that countries which have adopted a more progressive stance towards e-cigarettes have not seen a detrimental impact on smoking rates. If anything, the results suggest that - more likely than not - e-cigarettes have displaced harmful cigarettes in those countries so far. However, as this is fast moving field, with new technologies entering the market every year, it remains important to continue monitoring national data."

Professor Brian Ferguson, Director of the Public Health Research Programme (NIHR) commented: 

"The initial findings from this study are valuable but no firm conclusions can be drawn yet. More research is needed in this area to understand further the impact that alternative nicotine delivery products, such as e-cigarettes, might have on smoking rates.”

This research, published in the journal Public Health Research, was funded by the National Institute for Health and Care Research. 

END

NOTES FOR EDITORS

• Pesola F, Phillips-Waller A, Beard E, Shahab L, Sweanor D, Jarvis M, Hajek P. Effects of reduced-risk nicotine-delivery products on smoking prevalence and cigarette sales: the GIRO observational study. Public Health Res 2023;11(XX). https://doi.org/10.3310/RPDN7327
• For more information on this release, to receive a copy of the paper or to speak with the researcher, please contact Laurence Leong in Queen Mary’s press office: l.leong@qmul.ac.uk

About Queen Mary University of London

At Queen Mary University of London, we believe that a diversity of ideas helps us achieve the previously unthinkable.

Throughout our history, we’ve fostered social justice and improved lives through academic excellence. And we continue to live and breathe this spirit today, not because it’s simply ‘the right thing to do’ but for what it helps us achieve and the intellectual brilliance it delivers.

Our reformer heritage informs our conviction that great ideas can and should come from anywhere. It’s an approach that has brought results across the globe, from the communities of east London to the favelas of Rio de Janeiro.

We continue to embrace diversity of thought and opinion in everything we do, in the belief that when views collide, disciplines interact, and perspectives intersect, truly original thought takes form.

About UCL – London’s Global University

UCL is a diverse global community of world-class academics, students, industry links, external partners, and alumni. Our powerful collective of individuals and institutions work together to explore new possibilities.

Since 1826, we have championed independent thought by attracting and nurturing the world's best minds. Our community of more than 50,000 students from 150 countries and over 16,000 staff pursues academic excellence, breaks boundaries and makes a positive impact on real world problems.

We are consistently ranked among the top 10 universities in the world and are one of only a handful of institutions rated as having the strongest academic reputation and the broadest research impact.

We have a progressive and integrated approach to our teaching and research – championing innovation, creativity and cross-disciplinary working. We teach our students how to think, not what to think, and see them as partners, collaborators and contributors.

For almost 200 years, we are proud to have opened higher education to students from a wide range of backgrounds and to change the way we create and share knowledge.

We were the first in England to welcome women to university education and that courageous attitude and disruptive spirit is still alive today. We are UCL.

www.ucl.ac.uk | Follow @uclnews on Twitter | Read news at www.ucl.ac.uk/news/ | Listen to UCL podcasts on SoundCloud | Find out what’s on at UCL Minds

About the University of Ottawa 

Rooted in our bilingual and Francophone DNA, we are evolving at the intersection of many cultures. Located in Canada’s capital, a gateway to the world, we possess a unique platform to respond with energy, creativity, and scale to the global challenges and opportunities our world offers. With an active focus on equity, diversity, and inclusion, we will thrive like never before. 

Already in this new millennium we have rocketed into the top 1% of the world’s 20,000+ universities with our research reputation. We have doubled our enrolment with students from across Canada, as well as from 147 countries around the globe, choosing uOttawa. 

Our international influence is surging, with institutional partnerships in Europe, Asia and Africa multiplying rapidly – including membership in the U7 Alliance of world universities. 

Meanwhile our research and programs in Cybertech, health, science, social justice, sustainability, education, and entrepreneurship continue to impact communities across Canada and around the globe every single day. Our scientists and academicians are driving progress in ethical AI and technology development, in clean growth and innovation and in action- oriented research on aging, active and healthy living, lifelong learning, and well-being, to name but a few. 

At uOttawa we are driven by the urge to challenge the status quo, the will to make an impact, and the ambition to become a catalyst for change.

About The National Institute for Health and Care Research (NIHR)

The mission of the National Institute for Health and Care Research (NIHR) is to improve the health and wealth of the nation through research. We do this by:

· Funding high quality, timely research that benefits the NHS, public health and social care;

· Investing in world-class expertise, facilities and a skilled delivery workforce to translate discoveries into improved treatments and services;

· Partnering with patients, service users, carers and communities, improving the relevance, quality and impact of our research;

· Attracting, training and supporting the best researchers to tackle complex health and social care challenges;

· Collaborating with other public funders, charities and industry to help shape a cohesive and globally competitive research system;

·  Funding applied global health research and training to meet the needs of the poorest people in low and middle income countries.

NIHR is funded by the Department of Health and Social Care. Its work in low and middle income countries is principally funded through UK Aid from the UK government.

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JOURNAL

Public Health Research

Researchers discover potential treatment for nicotine dependence

Theta-burst transcranial magnetic stimulation therapy may reduce cigarette cravings

Peer-Reviewed Publication

UNIVERSITY OF MISSOURI-COLUMBIA

New research from the University of Missouri School of Medicine suggests there may be another way to treat cigarette cravings. Researchers found that theta-burst transcranial magnetic stimulation (TBS) – strong, rapidly fluctuating magnetic field pulses that can affect brain activity – can lead to improved self-control, reduced cravings and as a result, less smoking.

People with nicotine dependence tend to have significant structural and functional differences in the brain, compared to healthy non-smokers. Smoking cigarettes has been shown to be associated with less grey matter, which means they have less neurons and other cells in the brain.

Research suggests these differences may affect inhibitory control (IC), which is our control over automatic urges and response to stimuli – what enables humans to stop an impulsive reaction to something.

“Having difficulties with IC may make it harder to avoid smoking when the urge arises, in response to all the cues and contexts in the environment that trigger the behavior to light a cigarette,” said lead author Brett Froeliger, PhD, professor of Psychiatry.

TBS refers to when magnetic pulses are applied to the brain in bursts of three and come in two forms: continuous TBS (cTBS) and intermittent TBS (iTBS). cTBS consists of applying these three bursts repeatedly for 40 seconds, whereas iTBS applies the same number of pulses irregularly for more than 190 seconds.

Magnetic stimulation has been used to treat other mental illnesses and disorders. cTBS has been experimentally tested to treat generalized anxiety disorder, whereas iTBS to the left dorsolateral prefrontal cortex – a part of your brain responsible for cognitive processes – is FDA-approved for treating major depressive disorder.

The study involved 37 participants, mostly in their late 40’s, and examined the effects of both cTBS and iTBS to the right inferior frontal gyrus, a brain region heavily involved with IC. Researchers found that cTBS improved IC, whereas both cTBS and iTBS reduced cravings and, subsequently, smoking.

“Identifying treatments that improve IC may help reduce smoking and can potentially help with preventing relapse following when a person attempts to quit smoking,” Froeliger said. “Treatments that improve IC may also help disrupt the cycle of drug use among individuals with other substance use disorders; however, further research is needed to examine the clinical value of TBS for treating substance use disorders.”

“Effects of Hyperdirect Pathway Theta-Burst Transcranial Magnetic Stimulation on Inhibitory Control, Craving, and Smoking in Adults with Nicotine Dependence: A Double-Blind Randomized Crossover Trial” was recently published in Biological Psychiatry CNNI.

In addition to Froeliger, study authors include Muaid Ithman, MD, associate professor of clinical psychiatry; MU PhD student Spencer Upton; TBS technician and data analyst Alexander Brown and other researchers from the University of South Carolina and Stanford University. The authors claim no conflicts of interest.

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JOURNAL

Biological Psychiatry

DOI

10.1016/j.bpsc.2023.07.014 

METHOD OF RESEARCH

Randomized controlled/clinical trial

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Effects of Hyperdirect Pathway Theta-Burst Transcranial Magnetic Stimulation on Inhibitory Control, Craving, and Smoking in Adults with Nicotine Dependence: A Double-Blind Randomized Crossover Trial

UK

Swap-to-stop’ but let us shop - say vapers

Peer-Reviewed Publication

UNIVERSITY OF EAST ANGLIA

A Government scheme to give out free vapes to smokers appeals to most but not all, according to new research from the University of East Anglia (UEA).

The 'Swap-to-Stop' scheme was announced earlier this year - providing a million e-cigarettes to disadvantaged people who smoke.

A new study published today supports the scheme, with people who vape saying that this type of approach might have helped them if it had been available when they attempted to quit.

But the research also shows that accessing vapes via the NHS might not be appealing to everyone, because some people don't see e-cigarettes as treatments but more as consumer products that they can shop for themselves.

The team says there is a place for both commercial and medical routes to vaping for quitting smoking to satisfy people's personal preferences.

Lead researcher Dr Emma Ward, from UEA’s Norwich Medical School, said: “The vast majority of people who have quit smoking via vaping will have done so without any support from healthcare professionals.

“However, using vapes to quit smoking has been supported by the NHS and there are guidelines for healthcare professionals to support patients looking to quit smoking with vaping.

“In April 2023, the Government announced a 'Swap-to-Stop' scheme – to help achieve its Smokefree 2030 target of less than 5 per cent of people smoking in England by 2030.

“The scheme will be the biggest Government supported stop smoking scheme to date using e-cigarettes. The scheme will use vaping products that are also available to buy commercially.

“We wanted to better-understand how well it might work.”

The team interviewed 136 people from across the UK – nearly all of whom had quit smoking via vaping.

They asked them how helpful they would have found e-cigarettes being provided by the NHS when they were attempting to quit. They also asked for their views on different ways to access vaping for quitting smoking.

Dr Ward said: “Our research shows that people who quit smoking using commercially purchased vapes believe they might have benefitted from the NHS providing e-cigarettes and support if it had been available to them when they were quitting.

“Vaping being available via healthcare professionals offers reassurance around the effectiveness of e-cigarettes in helping people quit smoking and potential harms.

“However, it is unlikely that one type of e-cigarette will suit everyone seeking to quit and our research highlights how important being able to choose vaping products in a commercial environment is for some quitters.

“People who vape believe they have benefited from being able to choose vaping products in shops to get the right mix of device and flavours to work best for them to help them to permanently stop smoking.

“Even those who do achieve success with vapes given to them by the NHS are likely to continue to use shops to buy ongoing vaping supplies.

“So, we argue that there is a place for both commercial and medical routes to vaping to help people stop smoking.”

This research was carried out in collaboration with London South Bank University. It was funded by Cancer Research UK.

‘Medicalisation of Vaping in the UK? E-cigarette users’ perspectives on the merging of commercial and medical routes to vaping’ is published in the journal Perspectives in Public Health.

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JOURNAL

Perspectives in Public Health

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE PUBLICATION DATE

7-Aug-2023

SILVER LINING

The health risks of COVID-19 spurred more smokers to quit

New UC San Diego Rady School of Management study is first to track smoking behavior at the individual level during the pandemic

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SAN DIEGO

 

IMAGE: SALLY SADOFF, THE RAFAEL AND MARINA PASTOR CHANCELLOR’S RADY SCHOOL OF MANAGEMENT ENDOWED FACULTY FELLOWSHIP AND ASSOCIATE PROFESSOR OF ECONOMICS AND STRATEGY. view more 

CREDIT: UC SAN DIEGO'S RADY SCHOOL OF MANAGEMENT

Being a smoker makes it more likely for a person to have severe COVID-19 symptoms, require hospitalization or die, which may explain a sharp decrease in smoking behavior among the Danish population during the pandemic, according to new research.

The study from the University of California San Diego’s Rady School of Management. reveals that cigarette purchases among regular smokers decreased by about 20-30% and quitting rates increased by about 10 percentage points from March 2020 to January of 2021. Regular smokers not only purchased cigarettes less frequently, they also cut down on the quantity.

“The pandemic led to reductions in physical activity, increases in stress and declines in mental well-being, all factors commonly associated with triggering higher tobacco use; however, we find evidence of sustained decreases in smoking, which could be a bright spot in the pandemic,” said Sally Sadoff, corresponding author of the study and associate professor of economics and strategy at the Rady School of Management. “The health risks associated with COVID-19 and smoking may help some smokers overcome a key barrier to quitting – that the enjoyment of smoking is felt in the present and health costs are usually felt in the future.”

The paper published in the journal Communications Medicine, shows that declines in smoking were sustained for at least the first year of the pandemic and quitting rates lasted at least six months. These findings suggests COVID-19 may lead to a persistent decline in smoking.

In Denmark, about 17% of the population smokes and in the U.S., about 12.5% percent of the population are smokers.

“Though we cannot make an apples-to-apples comparison to the U.S. due to data limitations, we suspect there was a decline in smoking in this country and others during the same time period,” Sadoff said.

This study is the first to utilize cigarette sales data for both smokers and non-smokers during the pandemic, rather than survey information. The data in the study were made available through Spenderlog, an app that allows users to track their spending on groceries.

Sadoff and co-authors analyzed the grocery purchasing data of 4,042 Danish residents who use the Spenderlog app. The sample is largely representative of the Danish population in terms of age, ethnicity, socioeconomic status and education level.

The researchers find that weekly cigarette purchase rates declined by 24% and average quantities declined by 12% between March 2020 and the end of that year.

However, the data also reveals that social smoking had a slight increase during this same time.

“Contrary to some assumptions, social distancing was not reason there was a drop in smoking because our data reveals that regular smokers, those more likely to smoke alone and those at the highest health risk from smoking, had the strongest reaction to the threat of COVID-19,” Sadoff said.

She continued, “If the decline in smoking we document persists, not only could it help decrease the risks from COVID-19 as new variants emerge, but also have meaningful, longer-term benefits on population health and life expectancy beyond the pandemic.”

The paper “Sustained decline in tobacco purchasing in Denmark during the COVID-19 pandemic” was co-authored by Toke R. Fosgaard of the University of Copenhagen and Alice Pizzo of the Copenhagen Business School.

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JOURNAL

Communications Medicine

DOI

10.1038/s43856-022-00160-1 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Sustained decline in tobacco purchasing in Denmark during the COVID-19 pandemic

ARTICLE PUBLICATION DATE

1-Aug-2022

Electronic cigarettes help smokers with schizophrenia quit

OXFORD UNIVERSITY PRESS USA

Research News

 

A new study in Nicotine & Tobacco Research, published by Oxford University Press, finds that the use of high-strength nicotine e-cigarettes can help adults with schizophrenia spectrum disorders quit smoking.

Some 60-90% of people with schizophrenia smoke cigarettes, compared to 15-24% of the general population. The researchers from the University of Catania, in collaboration with colleagues from City University of New York and Weill Medical College of Cornell University, have assessed here the feasibility of using a high-strength nicotine e-cigarette to modify smoking behavior in people with schizophrenia spectrum disorders who smoke cigarettes. In this study 40 adults with schizophrenia spectrum disorders who smoked and did not intend to reduce or quit smoking participated in a 12-week study using Juul e-cigarettes loaded with 5% nicotine pods with a follow-up visit at 24 weeks. Researchers measured smoking frequency, smoking reduction, carbon monoxide expired air reduction, smoking cessation, and continuous abstinence 24 weeks after the study began.

Some 40% of participants had stopped smoking traditional cigarettes by the end of 12 weeks. Researchers observed an overall, sustained 50% reduction in smoking or complete smoking abstinence in 92.5% of participants at the end of 12 weeks. Researchers also observed an overall 75% reduction in median daily cigarette consumption from 25 to 6, by the end of the 12 weeks.

After six months, 24 weeks after the study began, 35% of participants had completely stopped smoking conventional tobacco cigarettes, while continuing to use e-cigarettes. Researchers here also measured a significant decrease in daily cigarette consumption was also confirmed at the end of 24 weeks. The study's authors report that 57.5% of participants reduced their cigarette usage by over 50%.

Additionally, researchers found that participants' mean blood pressure, heart rate and weight measurably decreased between the start of the study and the 12-week follow up. Positive and negative symptoms of schizophrenia were not significantly different after using e-cigarettes throughout the whole duration of the study. At the end of the study 61.9% of participants reported feeling more awake, less irritable, and experiencing greater concentration, and reduced hunger.

"Smoking is the primary cause of the 15-25 years mortality gap between users of mental health services and the general population, said one of the paper's authors, Riccardo Polosa, professor of Internal Medicine at the University of Catania (Italy). "This study demonstrates that switching to high-strength nicotine e-cigarettes is a feasible highly effective smoking cessation method for smokers who have schizophrenia. And it improves their quality of life too!"

To request a copy of the study, please contact:

Emily Tobin
emily.tobin@oup.com

Sharing on social media? Find Oxford Journals online at @OxfordJournals

ANTI SMOKING LOBBY

Legalization of cannabis threatens clean indoor air and public health

Most localities that allow onsite cannabis smoking lounges do not protect nonsmokers from the ill effects of secondhand cannabis smoke, researchers report in the American Journal of Preventive Medicine

Peer-Reviewed Publication

ELSEVIER

Ann Arbor, September 7, 2021 – After years of progress on protections against secondhand tobacco smoke, multiple states and local governments now allow indoor smoking of cannabis at licensed cannabis businesses. A new study in the American Journal of Preventive Medicine, published by Elsevier, found that over 50 localities in the United States allow indoor smoking at these businesses, exposing customers and employees to secondhand cannabis smoke (SHCS).

“While many states maintain strong tobacco smoking and vaping bans to protect public health, our research reveals that some state and local laws exempt cannabis smoke from clean air laws and open the door to smoke-filled businesses, defeating decades of public health advances,” said first author Thomas L. Rotering, MPH, of the Center for Tobacco Control Research and Education, and the Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco, San Francisco, CA, USA.

The researchers systematically searched legal databases, public reporting, government websites, and local laws that address cannabis smoking lounges. They found wide variation in how state and local governments address SHCS exposure in these businesses. All of the 11 states that have legalized adult-use cannabis as of June 2020 prohibit consumption in public places, but six states (Alaska, California, Colorado, Illinois, Massachusetts, and Michigan) allow onsite consumption in licensed cannabis businesses subject to local government approval. No state prohibits local governments from implementing more rigorous requirements. Massachusetts only allows onsite consumption through vaporization or other nonsmoking forms of consumption involving heat.

Although the only effective means of preventing the health problems associated with SHCS is to require a smoke-free environment, most local laws either do not address SHCS or use ineffective ventilation or engineering requirements. Of the 56 localities that permit onsite cannabis consumption businesses, only 9% require that indoors be smoke-free. Twenty-three percent of local governments provide for smoking in isolated rooms but only require that the smoke not drift to nonsmoking areas or that there be a smoke-free employee viewing area. Other common local legal requirements address onsite odor control, ventilation/filtration, and building location. Such requirements are often vague, and the investigators observe that they resemble the tobacco industry’s “accommodation” framework by allowing smoking inside and positioning ventilation or engineering controls as solving secondhand smoke.

“After decades of progress in clearing the indoor air of tobacco smoke, we are seeing it replaced with cannabis smoke using the same discredited arguments the tobacco industry used in its unsuccessful fight against tobacco smoke restrictions. We need to learn from the past and keep the air clean for all,” commented senior investigator Stanton A. Glantz, PhD, retired from the Center for Tobacco Control Research and Education, and the Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco, San Francisco, CA, USA.

Some cannabis advocates argue that designating indoor spaces for renters, tourists, and people experiencing homelessness to smoke or vape is the only reasonable alternative to illegally consuming in public or exposing nonsmokers to SHCS. The investigators suggest that reasonable alternatives may include permitting outside, out-of-view cannabis use at retailers, or allowing only the use of non-inhalable modes of administration that do not pollute the air. Local officials could consider allowing multiunit housing or other places serving these groups to create outdoor, designated consumption smoking areas out of public view.

Policymakers should be made aware that ventilation and other engineering interventions cannot fully protect workers and patrons. “Health authorities and local leaders should educate policymakers on the science of secondhand smoke remediation and advocate for the same standards for secondhand cannabis smoking and vaping that apply to tobacco, particularly because other cannabis administration modes do not pollute the air,” said the authors in their paper. “Where onsite smoking or vaping is permitted, even measures such as truly separate indoor and outdoor smoking areas may reduce but not eliminate SHCS exposure to patrons, staff, and residents.”

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JOURNAL

American Journal of Preventive Medicine

DOI

10.1016/j.amepre.2021.05.012 

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Emerging Indoor Air Laws for Onsite Cannabis Consumption Businesses in the U.S.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases

Research Letter 

Substance Use and Addiction

September 7, 2021

Association of Marijuana Legalization With Marijuana Use Among US High School Students, 1993-2019

D. Mark Anderson, PhD¹; Daniel I. Rees, PhD²; Joseph J. Sabia, PhD³; et alSamuel Safford, MA³

Author Affiliations Article Information

JAMA Netw Open. 2021;4(9):e2124638. doi:10.1001/jamanetworkopen.2021.24638

Introduction

Thirty-six states have legalized medical marijuana and 18 states have passed recreational marijuana laws (RMLs). Organizations such as the American Academy of Pediatrics are concerned that legalization will encourage youth marijuana use.¹ Marijuana use during adolescence may adversely affect areas of the prefrontal cortex, which control important cognitive processes.¹

Using data from the Youth Risk Behavior Survey (YRBS) for the period 1993-2017, Anderson et al² found that RML adoption was associated with an 8% decrease in the odds of marijuana use among high school students. These authors, however, had prelegalization and postlegalization data from only 7 states and pre– and post–recreational sales data from only 3 states, calling into question the generalizability of their results.³

Using data from the YRBS for the period 1993-2019, this study provides updated estimates of the association between legalization and adolescent marijuana use. During this extended period, pre- and post-RML data from the YRBS are available from 10 states; 7 states contributed more than one wave of post-RML data, and these same 7 states contributed data to the YRBS before and after the first dispensary sales began. Anderson et al³ had multiple waves of post-RML data from 3 states.

Methods

Following Anderson et al,² national and state YRBS data were pooled in this repeated cross-sectional study. Ethical review was not required because analyses of secondary, deidentified data are considered exempt from requiring institutional review board approval by the San Diego State University Institutional Review Board. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guidelines.

Multivariable logistic regression was used to estimate the association between legalization and marijuana use. Effective legalization dates come from Anderson and Rees.⁴ To control for time-invariant factors at the state level and common trends, all models were adjusted for 50 state and 13 survey wave indicators. Alternative models were further adjusted for individual- and state-level characteristics; event-study estimates were produced by replacing the RML indicator with a series of leads and lags. Two-sided hypothesis tests were used, and estimates were considered significant if P < .05. Analyses were conducted with STATA 16.1 (StataCorp).

Results

The mean (SD) age of YRBS respondents was 15.9 (1.23) years, 51.4% of respondents reported as female, and 57.6% reported as non-Hispanic white. The first two columns of the Table show estimated odds ratios (ORs) of current and frequent marijuana use, adjusted for state and survey-wave indicators. In the third and fourth columns, ORs were further adjusted for individual- and state-level covariates.

Based on the pooled YRBS data, and in the fully adjusted models, RML adoption was not associated with current marijuana use (OR, 1.00; 95% CI, 0.92-1.10) or frequent marijuana use (OR, 0.98; 95% CI, 0.90-1.07). In the fully adjusted models, medical marijuana law (MML) adoption was associated with a 6% decrease (OR, 0.94; 95% CI, 0.89-0.98) in the odds of current marijuana use and a 7% decrease (OR, 0.93; 95% CI, 0.87-0.99) in the odds of frequent marijuana use. Estimates from separate analyses of the national and state YRBS and estimates of the association between the opening of the first recreational dispensary and marijuana use were qualitatively similar to those above (Table).⁵

Finally, the Figure shows RML event-study estimates (Panel A). Prior to legalization, there was no association with marijuana use, suggesting the parallel-trends assumption held. After 2 or more years, RML adoption was associated with a decrease in marijuana use (OR, 0.85; 95% CI, 0.76, 0.95). Panel B of the Figure shows an event study for MML adoption.

Discussion

Consistent with estimates from prior studies, there was little evidence that RMLs or MMLs encourage youth marijuana use.^2,6 Contrary to results of the study by Anderson et al² the overall association between RML adoption and marijuana use among adolescents was statistically indistinguishable from zero. One limitation of this study is that RMLs are a relatively new phenomenon. As more postlegalization data become available, researchers will be able to draw firmer conclusions about the relationship between RMLs and adolescent marijuana use.

Back to top

Article Information

Accepted for Publication: July 8, 2021.

Published: September 7, 2021. doi:10.1001/jamanetworkopen.2021.24638

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2021 Anderson DM et al. JAMA Network Open.

Corresponding Author: D. Mark Anderson, PhD, Department of Agricultural Economics and Economics, Montana State University, PO Box 172920, Bozeman, MT 59717-2920 (dwight.anderson@montana.edu).

Author Contributions: Dr Sabia had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: All authors.

Acquisition, analysis, or interpretation of data: Anderson, Sabia, Safford.

Drafting of the manuscript: Anderson, Rees, Sabia.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Rees, Sabia, Safford.

Obtained funding: Anderson, Sabia.

Supervision: Anderson, Sabia.

Conflict of Interest Disclosures: Dr Sabia reported grants from Troesh Family Foundation and grants from Charles Koch Foundation during the conduct of the study. No other disclosures were reported.

Funding/Support: Dr Anderson acknowledges partial support from a Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (NIH) research infrastructure grant, R24 HD042828, to the Center for Studies in Demography and Ecology at the University of Washington. Dr Sabia and Mr Safford acknowledge partial support from the Center for Health Economics & Policy Studies (CHEPS) at San Diego State University, including grant funding received from the Charles Koch Foundation.

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Disclaimer: The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

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Committee on Substance Abuse, Committee on Adolescence; Committee on Substance Abuse Committee on Adolescence.  The impact of marijuana policies on youth: clinical, research, and legal update.   Pediatrics. 2015;135(3):584-587. doi:10.1542/peds.2014-4146PubMedGoogle ScholarCrossref

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Anderson  DM, Hansen  B, Rees  DI, Sabia  JJ.  Association of marijuana laws with teen marijuana use: new estimates from the Youth Risk Behavior Surveys.   JAMA Pediatr. 2019;173(9):879-881. doi:10.1001/jamapediatrics.2019.1720
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Anderson  DM, Rees  DI, Sabia  JJ.  Challenging the association of marijuana laws with teen marijuana use-reply.   JAMA Pediatr. 2020;174(1):99-100. doi:10.1001/jamapediatrics.2019.4238
ArticlePubMedGoogle ScholarCrossref

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Anderson  DM, Rees  DI. The public health effects of legalizing marijuana. NBER Working Paper No. 28647. Accessed August 13, 2021. https://www.nber.org/papers/w28647

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Jones  CM, Underwood  JM, Volkow  ND.  Challenging the association of marijuana laws with teen marijuana use.   JAMA Pediatr. 2020;174(1):99. doi:10.1001/jamapediatrics.2019.4235
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Coley  RL, Kruzik  C, Ghiani  M, Carey  N, Hawkins  SS, Baum  CF.  Recreational marijuana legalization and adolescent use of marijuana, tobacco, and alcohol.   J Adolesc Health. 2021;69(1):41-49. doi:10.1016/j.jadohealth.2020.10.019PubMedGoogle ScholarCrossref