Association Between Recreational Marijuana Legalization in the United States and Changes in Marijuana Use and Cannabis Use Disorder From 2008 to 2016

Using genetic information to inform policy on cannabis

Due to the recentness of changes to marijuana policies in a number of states, the effect on adolescent use and perceptions is not yet well understood. This study examines change in adolescent marijuana use and related perceptions in Colorado, before and after the implementation of legal commercial sale of recreational marijuana for adults starting on January 1, 2014. The data are from a repeated cross-sectional survey of a representative sample of Colorado high school students, with separately drawn samples surveyed in fall 2013 (prior to implementation) and fall 2015 (18months after implementation). We examined change in the prevalence of adolescent marijuana use, measured by lifetime use, past 30-day use, frequent use, and use on school property. To consider the possibility of heterogeneity in the change in marijuana use, we examined change in past 30-day marijuana use by demographic characteristics (sex, grade, race/ethnicity), school characteristics (poverty, percent minority), urbanicity of the school district, and whether the city or county permitted retail marijuana stores. There was an absence of significant effects for change in lifetime or past 30-day marijuana use. Among those reporting past 30-day use, frequent use and use on school property declined. There was a significant decline in the perceived harm associated with marijuana use, but we did not find a significant effect for perceived wrongfulness, perceived ease of access, or perceived parental disapproval. We did not find significant variability in past 30-day use by demographic characteristics or by school and community factors from 2013 to 2015. We did not find a significant effect associated with the introduction of legal sales of recreational marijuana to adults in Colorado on adolescent (illegal) use, but ongoing monitoring is warranted, including consideration of heterogeneity in the effects of marijuana policies.

The end of convergence in developmental patterns of frequent marijuana use from ages 18 to 30: An analysis of cohort change from 1976–2016

INTRODUCTIONPrevious research indicates that marijuana use may be interrelated with combustible tobacco use among U.S. adolescents and young adults. However, little is known about this relationship during older adulthood. The purpose of this study was: 1) examine the prevalence of past-month marijuana, cigarette and cigar use, and 2) assess the associations between demographic and tobacco-use variables with past-month marijuana use, among a nationally representative sample of U.S. adults 50 years and older.METHODSData are from the public-use files of the 2013 National Survey on Drug Use and Health (NSDUH). The sample consisted of 6325 adults aged ≥50 years.RESULTSOverall, 2.98% (N=216) of the sample reported past-month marijuana use; higher prevalence was noted for those who were past-month users of cigarettes (15.62%, N=1162) and lower prevalence was noted for those who were past-month users of cigars (2.68%, N=176). After accounting for covariables, past-month cigarette use was the strongest predictor of past-month marijuana use (adjusted odds ratio [AOR]=5.19, 95% CI, 3.51-7.66). Additionally, past-month cigar use showed a positive association with past-month marijuana use (AOR=2.41, 95% CI, 1.23-4.72).CONCLUSIONSTobacco prevention, cessation, and control efforts that target older adults should be tailored effectively to address the use of marijuana and other combustible tobacco products.

Substantial research has demonstrated the importance of implicit cognitive processes underlying substance use. However, there is a scarcity of research on implicit processes related to marijuana use. We adapted and tested the predictive validity (concurrent and prospective) of an implicit measure evaluating the strength of associations between marijuana and harm based on research demonstrating less marijuana use among individuals who report stronger explicit attitudes of marijuana's harms. A community sample of 187 U.S. young adults living in a state with legal recreational marijuana use completed an Implicit Association Test (IAT) evaluating marijuana-harm associations and measures of marijuana use and risk of cannabis use disorder (CUD) over time. The marijuana-harm IAT had good internal consistency, and scores did not vary as a function of biological sex, legal age status for recreational marijuana use, or college student status. Scores did vary as a function of lifetime and recent use such that lifetime and current abstainers had stronger marijuana-harm associations. Zero-inflated negative binomial regression models demonstrated that marijuana-harm IAT scores significantly predicted concurrent risk of CUD and use such that stronger marijuana-harm associations were associated with less use and risk of CUD. Results evaluating outcomes longitudinally found limited support for IAT scores predicting increases in use over time and no support for predicting changes in risk of CUD over time. Findings provide preliminary evidence that stronger marijuana-harm associations may act as a protective factor against marijuana use and risk of CUD.

Approximately 40 million adults use marijuana annually, making marijuana one of the most commonly used substances in the United States (SAMHSA, 2019). Men and emerging adults (ages 18-25) report higher prevalence of cannabis use disorders (CUDs) relative to women and older adults (CBHSQ, 2015; Khan et al., 2013). More frequent marijuana use is associated with greater likelihood of suicidal ideation (Ilgen et al., 2009), and past year use in emerging adults is associated with future suicide attempts (Pedersen, 2008). Similar to correlates of marijuana use, emerging adults and men have higher rates of suicidality (SAMHSA, 2019; Krug et al., 2002). Limited research has tested gender and age differences in comorbid CUDs and suicidality. The current study evaluated gender and age differences in CUDs only, suicidality only, or comorbid CUDs and suicidality in a national sample of adults. We hypothesized that men and emerging adults would be over-represented in comorbid CUDs and suicidality and CUDs only groups. Data were from four consecutive years (2015-2018) of the National Survey of Drug Use and Heath. Multinomial logistic regressions tested gender and age differences in adults with DSM-IV cannabis abuse or dependence (CUDs) only, suicidality only, and comorbid CUDs and suicidality, all compared to adults with neither CUDs or suicidality. Four separate regressions were conducted for passive suicidal ideation, active suicidal ideation, suicide planning, and suicide attempts. Gender was coded as male or female. Age groups were 18–25, 26–34, 35–49, and 50 years or older. Analyses controlled for survey year, race/ethnicity, sexual orientation, education, household income, past year major depressive episode, past year DSM-IV alcohol abuse or dependence, and past year illicit drug abuse or dependence other than CUDs. Men disproportionately reported CUDs only (ORs=1.73-2.19, p<.001) and comorbid CUDs and passive suicidal ideation, active suicidal ideation, and suicide planning (ORs=1.72-2.12, p<.01), but not attempts (OR=1.16, p=.45) relative to women. Men reported 22% higher odds of active suicidal ideation than women. Women reported 15% higher odds of suicide attempts than men. Gender differences in passive suicidal ideation and planning were not statistically significant. Compared to older age groups, emerging adults were significantly more likely to report CUDs only (ORs=1.74-10.49, p’s<.01) and showed 2.36 to 14.24 times greater odds of comorbid CUDs and all four forms of suicidality (p<.001). Emerging adults were at 18% to 66% higher odds of either passive or active suicidal ideation alone compared to all older age groups (p’s<.001). This study investigated the relations between CUDs, suicidality, gender, and age in a nationally representative sample of adults. Results indicated that men and emerging adults consistently reported the highest likelihood of negative outcomes. Next steps include determining the direction of the relationship between CUDs and increasing severity of suicidality. Further, development and investment in programs for emerging adults with CUDs and suicidality are vitally important given the striking risk profile compared to other age groups. Future research should include program development and evaluation as well as gathering more information on risk and protective factors for these populations.

This study involves a pilot investigation of associations between marijuana and synthetic cannabis use with PTSD symptoms among a young adult sample of U.S. veterans. In a cross-sectional survey of a community sample of 790 young adult U.S. veterans, we assessed demographics, combat severity, marijuana and synthetic cannabis use, expectancies of marijuana use, and PTSD symptoms. Overall, 61.8% and 20.4% of our sample reported lifetime and past-month marijuana use, whereas 17.0% and 3.4% reported lifetime and past-month synthetic cannabis use. Veterans screening positive for PTSD were more likely to use marijuana and synthetic cannabis in their lifetime and in the past month. Positive PTSD screens, as well as greater expectancies that marijuana leads to relaxation and tension reduction, were associated with past-month marijuana use in logistic regression analyses. Expectancies moderated the relationship between PTSD and marijuana use, such that those with positive PTSD screens reporting higher levels of relaxation and tension-reduction expectancies were most likely to report past-month marijuana use. Our findings suggest an association of PTSD symptoms with marijuana and synthetic cannabis use among young adult U.S. veterans. Future research should further investigate the link between PTSD and marijuana use, as well as the rates and consequences of synthetic cannabis use among veterans.

This study investigated the relationship, in adults 50 years and older, between self-reported past-month marijuana use and difficulty concentrating, remembering, or making decisions (SDCRMD) because of a physical, mental, or emotional condition, using the Behavioral Risk Factor Surveillance System (BRFSS). We relied on a sample of 294,000 adults (53.4% female), 50 years and older, from 21 U.S. states and two territories over 4 years (2016-2019). We conducted descriptive analyses to examine the prevalence of past-month marijuana use and SDCRMD and used multivariate logistic regression to examine the association between marijuana use and SDCRMD, controlling for demographic and health-related variables. The overall prevalence of SDCRMD was 11.0%, 95% confidence interval (CI) [10.6%, 11.5%], and the prevalence of self-reported past-month marijuana use was 7.1%, 95% CI [6.7%, 7.5%]. Of those reporting past-month marijuana use, 19.9%, 95% CI [17.8%, 22.1%] reported SDCRMD. Past-month marijuana users were 1.5, 95% CI [1.1, 2.1] times more likely to report SDCRMD than nonusers. Prevalence of past-month marijuana use was higher in states with legalization of both medical and recreational marijuana; however, prevalence of SDCRMD was not. We found a strong, positive, and statistically significant relationship between past-month marijuana use and SDCRMD. This finding serves as an important first step in identifying the relationship between older adults' self-reported marijuana use and their difficulty concentrating, remembering, and decision-making because of a physical, mental, or emotional condition; however, additional research is needed.

Background: People with HIV (PWH) report unique reasons for using marijuana. Similarly, they report unique concerns resulting from marijuana use. Assessing and understanding the reasons driving marijuana use among PWH could provide critical insights into how to help maximize the therapeutic benefits and minimize potential harms of marijuana use. The COVID-19 pandemic has impacted the access and use of substances globally. This study describes changes in patterns of marijuana use and reasons for those changes among PWH during the pandemic and implications for these findings in the future. The objectives of this study are to: 1) describe self-reported changes in marijuana use frequency during the COVID-19 pandemic among a cohort of PWH in Florida and 2) understand the reasons behind these changes through an analysis of open-ended qualitative questions. Methods: Data are cross-sectional and come from questions in a follow-up phone survey administered to a prospective cohort of PWH (75% current marijuana use) in Florida between May 2020-March 2021. Participants who used marijuana were asked about changes in their frequency of marijuana use due to the pandemic using a closed-ended quantitative survey and reasons for any reported changes in a qualitative open-ended question. Descriptive statistics and significance testing were completed in SAS 9.4. Qualitative data were analyzed using thematic analysis. Results: Among the total sample of 227 PWH (mean age 50, 50% men, 69% Black/African American, 14% Hispanic/Latino); 15% reported a decreased frequency of marijuana, 9% reported increased frequency, and 76% reported no change. The most common reason for increasing the frequency of marijuana use was to reduce the increased anxiety or stress experienced during the COVID-19 pandemic. Participants also reported that marijuana helped them cope with self-reported depression and other negative life events and helped reduce boredom while their regular activities were restricted. Concerns about the impacts of marijuana on COVID-19 risk, using the pandemic as an opportunity to reduce or quit marijuana use, and issues with obtaining marijuana were common reasons for decreased use. Additionally, some participants reported that a primary reason for using marijuana was the social aspect of using in a group, and without being able to gather they were less motivated to use, contributing to decreased use. Conclusions: Nearly one-quarter of the participants had changes in their marijuana use frequency during the pandemic, and most of the participants with a change decreased their frequency of use. The changes in the frequency of marijuana use experienced by PWH during the pandemic might continue and prevent a return to “normal,” so it is important to understand how to best address the new needs of PWH who use marijuana. Understanding the reasons behind changes in marijuana use patterns in this population—and what demographics, attitudes, and beliefs might differentiate those with increases, decreases, or no change in marijuana use—can allow researchers and providers to make greater connections between HIV-specific health outcomes and marijuana use. These findings provide specific targets for interventions to maintain or even improve health among PWH during public health emergencies and beyond.

Adolescent treatment admissions for marijuana following recreational legalization in Colorado and Washington

In light of the rapidly changing legal status of marijuana in the U.S., there has been increased interest in the potentially adverse outcomes of heavy marijuana use among young persons. The goal of this study was to investigate frequent marijuana use among undergraduates, and its association with the use of illicit substances, mental health problems, and stress. Undergraduates from one university in the Northeast were surveyed using a questionnaire derived from the American College Health Association-National College Health Assessment (N = 1,776). Logistic regression analyses were used to examine relationships between frequency of marijuana use and other substance use, binge drinking, negative consequences of drinking, mental health problems, and perceived stress. Analyses were adjusted for demographics differences such as gender, race, year in school, and sorority/fraternity membership. Approximately 1 in 12 undergraduates (8.5%) reported using marijuana more than 10 days in the past month. Frequent marijuana use was associated with increased likelihood of other substance use and alcohol-related negative outcomes. Marijuana use was associated with increased reports of anxiety, and frequent use was associated with depression and substance use problems. Perceived stress was not associated with marijuana use. These findings, indicating that frequent use is related to depression, other substance use and negative outcomes, contribute to our understanding of marijuana use among undergraduates. Given the relatively high prevalence of marijuana use among young persons, future studies should seek to uncover potentially causal relationships between frequent marijuana use and a variety of negative outcomes.

The Prevention of Nonmedical Marijuana Use Must Extend Past Adolescence

The current study uses data from the genetic subsample from the National Longitudinal Study of Adolescent Health (Add Health) in waves I and II (ages of 11–19 and 12–20 respectively) to investigate the interaction of the TaqIA polymorphism and poor parental socialization on changes in adolescent marijuana use. Results reveal that TaqIA interacts with poor parental rule setting, but not quality of mother–child communication, to influence changes in marijuana use. Adolescents who are homozygous for the A1 and whose parents allow the youth to set their own curfew experience significant increases in marijuana use during adolescence. In contrast, youths with the A1/A1 genotype whose parents do not allow the adolescent to set their own curfew experience significant decreases in the frequency of marijuana use. These results suggest that direct parental social control may effectively suppress the genetic risk of the A1/A1 genotype on marijuana use in adolescence. The study's limitations are noted.

The growing transition from lifetime marijuana use to frequent use among 12th grade students: U.S. National data from 1976 to 2019

Change in marijuana use and its associated factors among persons living with HIV (PLWH) during the COVID-19 pandemic: Findings from a prospective cohort