Medical Marijuana Policy and Outcomes

At the 2016 Society for Prevention Research (SPR) conference held in San Francisco (May 31-June 3), I’ll be presenting and discussing the latest findings from my recent paper, “Trends in registered medical marijuana participation across 13 US states and District of Columbia“, published this February in the journal of Drug and Alcohol Dependence. Continue reading Medical Marijuana Policy and Outcomes


How much tobacco is in a marijuana blunt?

Since marijuana ‘blunt’ smoking (i.e., rolling marijuana inside a hollowed cigar) is quite popular in the US, my research has been trying to understand the causes and potential health consequences of this mixing of tobacco and marijuana. However, a vexing and unanswered question is the degree to which blunt smokers are even exposed to nicotine. Continue reading How much tobacco is in a marijuana blunt?

Marijuana and Cannabinoids: A Neuroscience Research Summit

Date: March 22-23 @ National Institute of Health Campus, Bethesda, MD

I’ll be attending and presenting at the Marijuana and Cannabinoids: A Neuroscience Research Conference (link) focused on “on the neurological and psychiatric effects of marijuana, other cannabinoids, and the endocannabinoid system. Both the adverse and the potential therapeutic effects of the cannabinoid system will be discussed. The goal of this summit is to ensure evidence-based information is available to inform practice and policy, particularly important at this time given the rapidly shifting landscape regarding the recreational and medicinal use of marijuana.”

I’ll be presenting my poster, “What is the Current and Future Demand for Medical Marijuana?: Trends in Medical Marijuana Use by Selected Qualifying Conditions Compared across Nine U.S. States” Despite medical marijuana first being allowed in California in 1996, there is little data on how many people are using marijuana for certain qualifying conditions, like cancer, HIV/AIDS, epilepsy, multiple sclerosis, post-traumatic stress disorder (PTSD), or chronic pain. Using public data from state medical marijuana registries, I’m trying to estimate and compare the prevalence and trends over time in medical marijuana use for selected qualifying medical conditions. By looking at these trends, we might be able to estimate future demand and better prepare allocation of funding resources for research and public health.

Click on the image below to download a copy of my poster:

What is the Current and Future Demand for Medical Marijuana?: Trends in Medical Marijuana Use by Selected Qualifying Conditions Compared Across Nine US States

Screenshot 2016-06-06 12.10.34

2.7 Million Medical Marijuana Users in the US According to New Data

There are approximately 2.7 million adult medical marijuana users according to recent data from the US National Survey on Drug Use and Health (NSDUH). This estimate is based on a household survey of almost 68,000 people 12 year and older, covering all 50 states and the District of Columbia.

Approximately 29.8 million adults use marijuana each year. Those who had used marijuana in the past year were asked, “Was any of your marijuana use in the past 12 months recommended by a doctor or other health care professional?” About 9.1% (2.7 million) said they had used some medical marijuana in the last year, while 5.1% (1.7 million) had only used medical marijuana.

The estimated number of medical marijuana users in the US is higher than a previously reported estimate of 1.1 million based on the number of registered medical marijuana patients (

Cigarillo use increases estimates of teen smoking rates by half

New findings from the Monitoring the Future Study (links to PDF) show that when cigarillos (i.e., small cigars) are counted along with cigarettes, rates of tobacco smoking are higher by 67%. For example, rates of tobacco smoking among 8th, 10th, and 12th graders are 6.7% when only counting cigarettes, but after counting cigarillo use, the rate jumps to 11.2%. Cheap cigar and cigarillo use has increased over the past decade, while cigarette use has declined. Therefore, this finding is important to the degree teens are simply shifting to smoking different tobacco products. My suspicion is that much of the rise in cigarillo use is due to marijuana blunt smoking. However, there has been little published on the degree to which teens smoke cigarillos unmodified vs. modified for blunts, or the levels of nicotine exposure from blunt smoking. Both are areas of my active research.

Medical Marijuana Rose Faster in States with Dispensaries


Medical marijuana registrations rose faster in states with dispensaries, but only since 2009 when the federal government indicated it would stop raiding dispensaries complying with state medical marijuana laws. This is one of several interesting findings from a recently published study in the journal of Drug and Alcohol Dependence (link). [Update: A  copy of the article is available via or Researchgate links on my Publications page or at the side menu.]

Since 1996, 23 states and the District of Columbia have passed medical marijuana laws. In many of these states, patients must register in order to obtain medical marijuana. Using these data, a researcher at Johns Hopkins Bloomberg School of Public Health examined trends in medical marijuana participation over time since 2001 in 13 of these states and DC.

Findings show that prior to 2009, states reported relatively low levels of participation in medical marijuana programs. For example, states like Colorado had no more than 1.3 medical marijuana patients per every 1,000 adults. Then, in early 2009, the US Justice Department announced it would no longer treat individuals complying with state medical marijuana laws as a top priority for prosecution.

Rates of medical marijuana participation soon skyrocketed in states allowing dispensaries. By mid-2011, numbers in Colorado peaked at 34 per 1,000, and were even higher in Montana (41 per 1,000). In Michigan, which passed a medical marijuana law in late 2009, rates reached almost 16 per 1,000 by September 2011.

States that prohibited medical marijuana dispensaries saw much less increase. For example, through 2011, Hawaii had fewer than 10 per 1,000, and Alaska, Arizona, Rhode Island, and Vermont had fewer than 5 per 1,000. Oregon was the only state without dispensaries that had rates above 10 per 1,000.

Both Colorado and Montana passed legislation in mid-2011 that restricted dispensaries and patient access. In Colorado, dispensaries had to become licensed with the state and a moratorium on new licenses was put into effect. Recommending physicians also had to certify a bona fide patient-physician relationship. Medical marijuana participation rates dropped following these measures to 21 per 1,000 by the end of the year, but recovered to their current levels of 28 per 1,000.

In Montana, the drop in rates was more pronounced. Not only did the state remove the profit-motive for dispensaries, it also required patients seeking medical marijuana for chronic pain to prove an underlying cause. Following these changes, participation plummeted to a low of 9 per 1,000 in 2013, but has since risen to about 15 per 1,000. Rates dropped particularly among patients 21-30 years of age.

Participation also fell slightly in Michigan after the State Supreme Court declared dispensaries illegal in 2013. However, many continue to operate within the state.

In states that report numbers by gender, men continue to be more likely to participate in medical marijuana programs. However, in states like Colorado, Arizona, and Rhode Island, women appear to be catching up, and states that have had medical marijuana the longest (e.g., Alaska and Oregon) have numbers closer to equality.

In states that report numbers by age, many states show a large proportion of medical marijuana patients in their 50s (e.g., AK, MT, NV, OR, RI, VT). However, Colorado and Arizona have higher proportion of patients in young adulthood (i.e., 18-30). This suggests that medical marijuana is popular among both young adult and Baby Boomer groups.

The main caveat to these findings is that the data come from state-run medical marijuana registry programs with mandatory registration requirements. Therefore, states that operate only voluntary registries (i.e., California and Maine) or have no registry (i.e., Washington) could not be included in this study.

Trends in registered medical marijuana participation across 13 US states and District of Columbia.


New Publication: Past 15-Year Trends in Adolescent Marijuana Use: Differences by Race/Ethnicity and Sex

This paper was just accepted in Drug and Alcohol Dependence and is available online for advanced access. Visit the link to read the abstract and paper.

Johnson, Renee M., Brian Fairman, Tamika Gilreath, Ziming Xuan, Emily F. Rothman, Taylor Parnham, and C. Debra M. Furr-Holden. “Past 15-Year Trends in Adolescent Marijuana Use: Differences by Race/Ethnicity and Sex.” Drug and Alcohol Dependence, 2015. doi:10.1016/j.drugalcdep.2015.08.025.

Link to article


  • Male-female differences in adolescent marijuana use have decreased since 1999
  • Despite considerable changes to the legal status of marijuana in the US over the past 15 years, marijuana use among high school students has largely declined.
  • The prevalence of marijuana use among Black adolescents has been historically lower than for Whites. In 2013, the pattern reversed.

New Submission: Mood-related functional impairments associated with cannabis use among adults with recent depression

My new paper, Mood-related functional impairments associated with cannabis use among adults with recent depression, was just submitted for publication. This will be the third publication to come out of my PhD dissertation, Contributions to the Epidemiology and Mental Health Consequences of Cannabis Smoking (2014). See my Publications page to download a copy of my dissertation. One of my previous papers related to this topic, Are early-onset cannabis smokers at an increased risk of depression spells? (2012), was published in the Journal of Affective Disorders (also see Publications for copy). Check out the draft abstract below. – Brian

Authors: Brian J. Fairman


Background: Therapeutic benefits of cannabis for the treatment of depression remain unclear. Patients report smoking cannabis to alleviate depressed mood, but observational studies point to an increased risk for later depression. This study assessed the association between cannabis involvement and mood-related functional impairments, an important, but understudied clinical outcome for depression.

Methods: Annual surveys of adults with past 12-month depression (n=15,342) from the US National Survey on Drug Use and Health, 2009-2012 assessed total average mood-related functional impairments across four life domains using the Sheehan Disability Scale (SDS), and separately, for days of role impairment per annum. Cannabis involvement was measured in terms of past-year frequency, DSM-IV cannabis use disorder (CUD), and the number of cannabis problems.

Results: One-third of adults with depression experienced severe to very severe mood-related functional impairments, and an average of two months of role impairment. After accounting for other factors, weekly cannabis use or having a CUD was linked to an extra 10-15 days of mood-related role impairments. Adults with six or more cannabis problems had an extra month of these impairments. However, severity level of functional impairments did not differ by cannabis involvement after statistical adjustment.

Limitations: Cross-sectional study design prohibited investigating causality and changes in mood-related functional impairments over time.

Conclusions: Adults with depression may suffer from longer periods of role impairment, and experience no less severe mood-related functional impairment when smoking cannabis compared to abstinence. Findings question the likely effectiveness of cannabis smoking in reducing the burden of depression within the population.

Site Progress

Update: I’ve been able to import some older Blogger posts, which is the good news. However, keep in mind that some documents and files referenced in those older posts may not be accessible on the new WordPress site. I am working on getting these documents migrated over.

Greetings! Several pages of the site are up and running, including a short bio, my CV, list of publications, funding, and presentations. In the Bio section you’ll find a short description of myself and contact information. My CV page is where you can view my curriculum vitae or download a copy. Publications lists all of my current publications with easy access to Pubmed abstracts and/or a direct download of the journal article. The Funding page details my current and past research funding support. If you’d like samples of my recent presentations, lectures, or posters, please visit the Presentations page.

The last two sections not currently completed are Research Statement and Teaching Statement. The research statement will be an overview of my past, current, and future research accomplishments, agenda, and direction. The teaching statement will outline my teaching philosophy and goals for educating both undergraduates and graduate students.

Under Construction

Greetings! If you happened to stumble upon my website here, and you are wondering why it looks so dreadful, it is because I’m in the process of putting it together. When finished, what should you expect to find?

  1. My bio
  2. My CV
  3. Research and teaching statements
  4. Links to publications, posters, and conference presentations
  5. Updates on my current research projects
  6. News and thoughts relevant to the drug epidemiology and public health
  7. Funding (meager as it is)
  8. A Youtube page linking video presentations and tutorials
  9. Current book readings and past recommendations

Stay tuned.