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 Academic.edu 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.