Facts & Risks

Significance
Cannabis use is becoming more prevalent, including during developmentally sensitive periods such as pregnancy. Here we find that maternal cannabis use is associated with increased cortisol, anxiety, aggression, and hyperactivity in young children. This corresponded with widespread reductions in immune-related gene expression in the placenta which correlated with anxiety and hyperactivity. Future studies are needed to examine the effects of cannabis on immune function during pregnancy as a potential regulatory mechanism shaping neurobehavioral development.

Abstract
Significance: Cannabis use is increasing among cigarette smokers. If cannabis use is associated with cigarette dependence, a barrier to smoking cessation, this could have public health implications for tobacco control. The current study estimated the prevalence of cigarette dependence among US individuals who smoke cigarettes by cannabis use status, and investigated trends in cigarette dependence from 2002 to 2019 among cigarette smokers by cannabis use status and cigarette consumption (ie, cigarettes per day, CPD).

Objectives. To assess cannabis and alcohol involvement among motor vehicle crash (MVC) fatalities in the United States.

Methods. In this repeated cross-sectional analysis, we used data from the Fatality Analysis Reporting System from 2000 to 2018. Fatalities were cannabis-involved if an involved driver tested positive for a cannabinoid and alcohol-involved based on the highest blood alcohol concentration (BAC) of an involved driver. Multinomial mixed-effects logistic regression models assessed cannabis as a risk factor for alcohol by BAC level.

Neuropsychiatric toxicity (NPS) was common among patients presenting with cannabis toxicity to Michigan emergency departments (EDs), and they were more likely to also have used other substances, a researcher reported.

In the community-based analysis, among more than 1,000 patients presenting with cannabis toxicity over 2 years, 39.8% also were diagnosed with NPS, most often severe anxiety (36.1%) and altered mental status (22.3%), according to Erin Leach, a fourth-year medical student at Michigan State University College of Human Medicine in Grand Rapids.

Question: What is the prevalence of adolescent cannabis vaping in the US and Canada?

Findings: This systematic review and meta-analysis reviewed 17 unique studies from the US and Canada, with a total of 198 845 adolescents, and found that the lifetime prevalence of cannabis vaping doubled from 2013 to 2020 (6.1% to 13.6%), past 12-month use doubled from 2017 to 2020 (7.2% to 13.2%), and the 30-day prevalence of cannabis vaping increased 7-fold from 2013 to 2020 (1.6% to 8.4%). Preference for cannabis products may be shifting from dried herb to cannabis oil.

Meaning: The findings of this study suggest that more effective prevention and response measures are required to mitigate the increasing prevalence of cannabis vaping among adolescents.

LAKE ELSINORE, Calif. — After a 2½-mile trek through thick brush, Mourad Gabriel stepped into a small clearing. A month earlier, this half-acre swath of the Cleveland National Forest, nearly invisible from the air, had been an illegal marijuana grow estimated to be worth more than $1.2 million. The U.S. Forest Service’s law enforcement officers had hacked down the plants, but Gabriel and his team were there to cart out nearly 3,000 pounds of trash and to clean up something else the drug traffickers left behind: poison.

A new investigative report from FiveThirtyEight about the booming legal marijuana business details claims of corruption in some testing labs.