Friday, February 15, 2019

US States Allowing Medical Cannabis Continue To See A DECLINE In Teen Cannabis Use

According to a large-scale, 16 year long study of American high school students, legalizing  medicinal cannabis has actually led to a drop in cannabis use among teenagers

Image result for medical cannabis

The study, published today in the American Journal of Drug and Alcohol Abuse used the results of an anonymous survey given to more than 800,000 high school students across 45 states to calculate the number of teens who smoke cannabis.

It found that the number of teenage cannabis smokers was 1.1% less in states that had enacted medical 
cannabis laws compared to those that hadn't, even when accounting for other important variables such as tobacco and alcohol policies, economic trends, youth characteristics and state demographics.

"We found that for every group of 100 adolescents, one fewer will be a current user of marijuana following the enactment of medical marijuana laws," says Dr Rebekah Levine Coley, a Professor of psychology at Boston College, who led the study.

"When we looked at particular subgroups of adolescents, this reduction became even more pronounced. For example 3.9% less Black and 2.7% less Hispanic youths now use marijuana in states with Medical Marijuana Laws".

As the survey was administered over a period of 16 years, the researchers were able to compare the changes in teenager's marijuana use in states that adopted Medical Cannabis Laws with those that hadn't, allowing them to more precisely pinpoint the effects of the legislation. Intriguingly, the study found that the longer the laws had been in place, the greater the reduction in teen cannabis use.

The results shine a light on an important debate taking place in America about the relative benefits and risks of decriminalizing 
cannabis. Decriminalization of cannabis is completely separate and different from recreational cannabis legalization, also important to note that this research only applies to medical cannabis states.  

"Some people have argued that decriminalizing or legalizing medical marijuana could increase cannabis use amongst young people, either by making it easier for them to access, or by making it seem less harmful." says Dr Rebekah Levine Coley.

"However, we saw the opposite effect. We were not able to determine why this is, but other research has suggested that after the enactment of medical marijuana laws, youths' perceptions of the potential harm of marijuana use actually increased. Alternatively, another theory is that as marijuana laws are becoming more lenient, parents may be increasing their supervision of their children, or changing how they talk to them about drug use."

Importantly the study found that unlike medical cannabis laws, legalizing recreational cannabis had no noticeable effect on adolescents' cannabis use, except for a small decline in cannabis smoking among 14-year olds and people from Hispanic backgrounds, and an increase in use among white adolescents. Neither policies had any effect on frequent or heavy users of cannabis users, suggesting that these students are not easily influenced by state laws.

Following recreational cannabis legalization in Washington state, among eighth and 10th graders in, perceived harmfulness of cannabis use decreased and cannabis use did increased following legalization of recreational cannabis use. California is seeing a slight increase in teen use, since recreational cannabis legalization, occurring mostly in the southern California. In Oregon, teenagers who had tried cannabis by 8th grade, the frequency of use during the following year increased 26% more for those who were in 9th grade after cannabis was legalized recreationally compared to those who were in 9th grade prior to legalization. The research results are published online in Psychology of Addictive Behaviors.

Background: Marijuana use carries risks for adolescents’ well-being, making it essential to evaluate effects of recent marijuana policies.

Objectives: This study sought to delineate associations between state-level shifts in decriminalization and medical marijuana laws (MML) and adolescent marijuana use.

Methods: Using data on 861,082 adolescents (14 to 18+ years; 51% female) drawn from 1999 to 2015 state Youth Risk Behavior Surveys (YRBS), difference-in-differences models assessed how decriminalization and MML policy enactment were associated with adolescent marijuana use, controlling for tobacco and alcohol policy shifts, adolescent characteristics, and state and year trends.

Results: MML enactment was associated with small significant reductions (OR = 0.911, 95% CI [0.850, 0.975]) of 1.1 percentage points in current marijuana use, with larger significant declines for male, Black, and Hispanic (2.7–3.9 percentage points) adolescents. Effects of MML increased significantly with each year of exposure (OR = 0.980, 95% CI [0.968, 0.992]). In contrast, decriminalization was not associated with significant shifts in use for the sample as a whole, but predicted significant declines in marijuana use among 14-year olds and those of Hispanic and other ancestry (1.7–4.4 percentage points), and significant increases among white adolescents (1.6 percentage points). Neither policy was significantly associated with heavy marijuana use or the frequency of use, suggesting that heavy users may be impervious to such policy signals.

Conclusion: As the first study to concurrently assess unique effects of multiple marijuana policies, results assuage concerns over potential detrimental effects of more liberal marijuana policies on youth use.

Abstract Link: