Prevalence of marijuana and other substance use before and after Washington State's change from legal medical marijuana to legal medical and nonmedical marijuana: Cohort comparisons in a sample of adolescents

ABSTRACT

Background: A growing number of states have new legislation extending prior legalization of medical marijuana by allowing nonmedical marijuana use for adults. The potential influence of this change in legislation on adolescent marijuana and other substance use (e.g., spillover or substitution effects) is uncertain. We capitalize on an ongoing study to explore the prevalence of marijuana and other substance use in 2 cohorts of adolescents who experienced the nonmedical marijuana law change in Washington State at different ages. Methods: Participants were 8th graders enrolled in targeted Tacoma, Washington public schools and recruited in 2 consecutive annual cohorts. The analysis sample was 238 students who completed a baseline survey in the 8th grade and a follow-up survey after the 9th grade. Between the 2 assessments, the second cohort experienced the Washington State nonmedical marijuana law change, whereas the first cohort did not. Self-report survey data on lifetime and past-month marijuana, cigarette, and alcohol use were collected. Results: Multivariate multilevel modeling showed that cohort differences in the likelihood of marijuana use were significantly different from those for cigarette and alcohol use at follow-up (adjusting for baseline substance initiation). Marijuana use was higher for the second cohort than the first cohort, but this difference was not statistically significant. Rates of cigarette and alcohol use were slightly lower in the second cohort than in the first cohort. Conclusions: This exploratory study found that marijuana use was more prevalent among teens shortly after the transition from medical marijuana legalization only to medical and nonmedical marijuana legalization, although the difference between cohorts was not statistically significant. The findings also provided some evidence of substitution effects. The analytic technique used here may be useful for examining potential long-term effects of nonmedical marijuana laws on adolescent marijuana use and substitution or spillover effects in future studies.     

Is marijuana identity associated with marijuana use and consequences? An examination of direct and interactive associations

Background: There is relatively little research examining the relationship between identity and marijuana-related outcomes (e.g., marijuana use and consequences). Identity may both directly help shape marijuana use behaviors and moderate the influence of other risk factors on marijuana outcomes. Objectives: The current study examines the relationship between marijuana identity and marijuana-related outcomes among emerging adults and explores whether identity moderates the relationships between nonidentity correlates (e.g., perceived norms and negative affect) of marijuana-related outcomes. Methods: College students who reported marijuana use in the past 12?months completed measures of marijuana identity, perceived norms, negative affect, frequency of marijuana use, and marijuana consequences. Conclusions/Importance: The results indicated that marijuana identity is associated with marijuana use frequency and moderates the relationship between perceived norms and marijuana consequences. The findings have implications for both identity-based and social norms-based interventions targeting problematic marijuana use among emerging adults.     

Is the Legalization of Marijuana Associated With Its Use by Adolescents?

Background: Growing moves in the U.S. toward relaxed laws surrounding adult use of marijuana raise concerns about concurrent increases in adolescent use of marijuana. Objectives: This study collected and analyzed primary data on the relationship between marijuana legalization status in U.S. states and adolescents' marijuana use. Methods: Recruited through social networking sites and youth-services community agencies, a sample of 1,310 adolescents from 48 U.S. states and the District of Columbia reported their use of marijuana. Youths' use rates were compared with the marijuana legalization status of youths' states of residence. Results: Study findings failed to show a relationship between adolescents' use of marijuana and state laws regarding marijuana use. Relationships were found for increased marijuana use by older youths, females, and non-Hispanic youths. Youths whose parents completed 2 or more years of college were less likely to report marijuana use than those whose parents completed fewer than 2 years of college. Conclusions: Albeit study findings do not support predictions of growing marijuana use by adolescents in states with liberalized adult use laws, further monitoring of adolescents' use with larger and more representative samples is needed.     

Washington State Recreational Marijuana Legalization: Parent and Adolescent Perceptions,Knowledge, and Discussions in a Sample of Low-Income Families

Background: In November 2012, Washington State and Colorado became the first states in the United States to legalize recreational marijuana use for adults, and Uruguay became the first country to allow the cultivation, distribution, possession, and use of marijuana. One possible consequence of these changes is increased adolescent marijuana use. Parents may mitigate this adverse consequence; however, whether parents and adolescents have accurate knowledge about the laws and are discussing marijuana use in light of the law changes is unknown. Objective: We examine perceptions, knowledge, and parent–child discussions about Washington State's recreational marijuana law in a sample of low-income families. Methods: Participants were a subset of families (n = 115) in an ongoing study that originally recruited parents and adolescents from middle schools in Tacoma, Washington. In summer 2013, when students were entering the 11^th grade, students and their parents were asked questions about the recreational marijuana law. Results: Participants perceived that their marijuana-related attitudes and behaviors changed little as a result of the law, and displayed uncertainty about what is legal and illegal. Most parents reported discussing the new law with their children but only occasionally, and conversations emphasized household rules, particularly among parent lifetime marijuana users compared to non-users. Conclusions/Importance: Results suggest that there should be a public health campaign focused on families that provides clear information about the recreational marijuana laws.     

The “Real” Number of Washington State Adolescents Using Marijuana,and Why: A Misclassification Analysis

Background: Although causality is difficult to establish, the regular use of marijuana has been associated with many adverse physiological and sociological consequences. There is considerable concern regarding marijuana use among adolescents, as the likelihood of adverse consequences increases significantly for this age group. The most comprehensive data for identifying risk factors for adolescent marijuana use is typically self-report, which may be over- or under-reported for a variety of reasons, including stigmatization, peer-pressure, or fear of being discovered. Objectives: To identify the prevalence of adolescent marijuana use in Washington State, and the associated risk and protective factors, while controlling for and estimating the extent of misreporting, and its determinants. Method: Data came from the 2014 Washington State Healthy Youth Survey. We accounted for missingness using chained multivariate imputation equations, resulting in 33,320 complete observations. Our model was estimated using a maximum likelihood multiple regression designed to control for systematic misclassification in binary dependent variables. Results: Approximately 12% of Washington adolescents claimed to have used marijuana in the past 30?days. Our estimates indicate this figure is likely closer to 18%. Determinants of use included use of other substances, gender, age, and measures of deviant social influences, personality/attitude, school and family bonds, bullying, and acquisition ease. Determinants of misreporting included use of other substances, gender, parental education, and family bonds. Conclusions: Failing to control for misreporting considerably underestimates the prevalence of marijuana use among adolescents. Our model allows us to better identify at-risk adolescents and inform focused prevention efforts.     

Gender Differences in the Relationships among Young Adults' Religiosity,Risk Perception,and Marijuana Use: A Moderated Mediation Model

Background: Studies show that religiosity is a protective factor against marijuana use. Given many religions' teachings to promote risk perception of substance use, risk perception possibly mediates the relationship between religiosity and marijuana use. Moreover, since males and females differ in religiosity, risk perception, and marijuana use, gender may moderate religiosity's indirect effect on marijuana use through risk perception and religiosity's direct effect on marijuana use. Despite substantial research on religiosity and adolescent marijuana use, little research has targeted the young adult population. Objectives: This study is the first to investigate the conditional nature of religiosity's influence on marijuana use through risk perception among young adults in the U.S. Methods: Using a nationally representative sample from the 2014 National Survey on Drug Use and Health (N = 12,646), conditional process analysis was examined through significant test of the index of moderated mediation. Additionally, mediation analysis was conducted in male (n = 6042) and female (n = 6604) groups separately to further characterize the nature of the relationships. Results: Religiosity's indirect effect on marijuana use through risk perception was found to be significantly different between males and females, while there were no gender differences in religiosity's direct effect on marijuana use. The indirect effect of religiosity on marijuana use via risk perception was significant among both males and females and was larger for females than males. Conclusion: Prevention interventions for young adults' marijuana use that incorporate religiosity should emphasize factors related to risk perception and have a gender informed perspective. Direction for future research is provided.     

Anxiety Symptoms and Coping Motives: Examining a Potential Path to Substance Use-Related Problems in Adolescents With Psychopathic Traits

Background: Although the relation between impulsive-irresponsible psychopathic traits and substance use is well-documented, the path to developing substance use problems is less understood in adolescents with these characteristics. Objectives: To examine the associations between psychopathy, anxiety, and substance use motives and a mechanism by which anxiety and alcohol and marijuana coping motives mediate the relation between psychopathic traits and substance use-related problems. Methods: A sample of 185 at-risk adolescent males from a residential military-style program reporting past alcohol or marijuana use (M age = 16.74) participated in the study. Results: Impulsive-Irresponsible psychopathic traits were uniquely and incrementally predictive of alcohol and marijuana use-related problems and anxiety. Anxiety and coping motives appeared to partially explain the association between impulsivity-irresponsibility and substance use-related problems. Conclusions/Importance: Findings suggest that youth expressing impulsive-irresponsible psychopathic traits may engage in problematic substance use at least partly as a function of heightened anxiety and a subsequent desire to alleviate distress by using alcohol or marijuana to cope.     

Person-Environment Interactions and Adolescent Substance Use: The Role of Sensation Seeking and Perceived Neighborhood Risk

ABSTRACT

Aims: This longitudinal study investigated person-environment interactions and adolescent substance use by examining whether, and if so how, early temperamental quality of sensation seeking interacted with current neighborhood characteristics to shape underage smoking, drinking, and marijuana use. Sample: Participants consisted of a community-representative sample of 352 adolescents. Methods: Early temperament was assessed when adolescents were between seven and 13 years of age, and current neighborhood characteristics (as perceived by participants and their mothers) and current adolescent substance use (self-reported smoking, drinking, and marijuana use in the past 30 days) were assessed approximately three years later. Results: The results from a zero-inflated negative binomial (ZINB) regression revealed a potent negative effect of the perceived neighborhood risk, such that riskier neighborhoods were associated with both a greater probability for any substance use among adolescents, and a greater frequency of substance use among those who were engaging in these behaviors. High sensation seeking was a risk factor only for frequency of substance use among adolescent extant users, but not for the likelihood of any use. In addition, a significant interaction between sensation seeking and neighborhood risk revealed that adolescent sensation seekers engaged in smoking, drinking, and marijuana use primarily under conditions of elevated neighborhood risk and increased opportunity for such behaviors. Conclusion: Underage substance use was affected by synergistic effects between personal and community risk factors.     

Understanding Public Attitudes Toward Cannabis Legalization: Qualitative Findings From a Statewide Survey

Background: Cannabis policy is rapidly evolving in the United States as more states legalize medical and non-medical marijuana. Public opinion has shifted dramatically in favor of marijuana legalization. Objectives: This study examines the reasons that people support, oppose, or are unsure about marijuana legalization, focusing on the participants’ own words. Methods: A statewide sample of adults (N?=?2,608) in Michigan completed an online survey about marijuana legalization (August and September 2016). Participants indicated whether they supported, opposed, or were unsure about marijuana legalization, and were then prompted to complete an open-ended response explaining the main reasons for their view. Thematic analysis was then used to code the open-ended responses (n?=?2,054) and analytic induction was used to evaluate the coding. Results: 48.1% of the sample supported cannabis legalization, 41.9% were opposed to legalization, and 10% were unsure. Harms associated with marijuana use were the most commonly given reasons for opposing legalization. Those who supported legalization were most likely to state that marijuana is less dangerous than other substances and has medical benefits. They also cited criminal justice reform and the potential for tax revenue as potential benefits of legalization. Reasons for supporting and opposing legalization differed based on gender, age, and recent marijuana use. Conclusions/Importance: Findings highlight nuances in public attitudes toward cannabis legalization. Many who support cannabis legalization recognize some potential negative consequences of these policy changes. Understanding views of cannabis is important as policies for marijuana use and sales become less restrictive.     

Operating a motor vehicle after marijuana use: Perspectives from people who use high-potency marijuana

ABSTRACT

Background: With advancing marijuana legalization in the United States, a primary concern is the possible increase in consequences relating to marijuana driving impairment, especially among people who use high-potency marijuana (i.e., extracts). In this study, the research team assessed the risk perception and experiences of driving under the influence of marijuana by investigating people who use extracts. Methods: Participants from 2 studies were queried about driving after using marijuana. In Study 1, phone interviews (n = 19) were conducted with people who use extracts. In Study 2, people who use extracts (n = 174) were recruited to participate in a nationwide survey via an online existing panel. Responses to marijuana and driving–related questions were qualitatively coded for themes (e.g., riskiness, engagement in behavior) developed by the research team. Results: Prominent themes identified in Study 1 suggested a belief that driving risk following marijuana use is dependent on the individual (i.e., response/tolerance) or the amount/type of marijuana consumed. This theme was corroborated by Study 2 participants. Those who perceived no or minimal risk from driving following marijuana use were more likely to report engagement in driving following extracts use. Conclusions: More research is needed to understand how marijuana, especially in its concentrated form, impacts driving ability in order to develop appropriate and scientifically sound regulations. Such research could subsequently fill the need to improve and more widely disseminate prevention messages on marijuana use and driving risks.     

An Exploration of Shifting Adolescent Use,Access and Risk Perception of Marijuana in the Caribbean Island of Barbados in 2006 and 2013

Abstract

In the face of more liberal attitudes globally towards marijuana, its use by adolescents is considered harmful. Some Caribbean countries, including the island of Barbados, are deliberating changes to their drug policies on marijuana from complete prohibition towards more liberal approaches. There is a need for the analysis of existing use, access and risk perception of marijuana among Barbados’ adolescent population given their vulnerability. This article employs data from two nationally representative secondary school surveys conducted in 2006 (n?=?2239) and 2013 (n?=?1339). A two-proportion z test was performed on the data to determine whether changes were significant at the 95% confidence level. While there has been an increase in prevalence and incidence rates, these were not significantly different in the two surveys. Significant changes were observed with the location of marijuana consumption and sources from which it was accessed. Finally, there was a significant decline in the perception that using marijuana regularly was harmful. Only the decline in frequent use being perceived as harmful was statistically significant. The results point to possible gaps in drug education and a greater need for the protection of the young.     

Adolescent Marijuana Use and Perceived Ease of Access Before and After Recreational Marijuana Implementation in Colorado

Background: As of January 1, 2017, eight states have approved laws for recreational marijuana use. While the social impacts of these changes remain under debate, the influence on adolescent marijuana use is a key policy and health issue across the U.S. Objective: To examine changes in adolescent marijuana-use behaviors in the first year after recreational marijuana implementation in Colorado, and to analyze the effect of retail marijuana store proximity on youth use and perceptions. Method: Secondary analysis of Healthy Kids Colorado Survey data from 40 schools surveyed before and after recreational marijuana sales were implemented (2013 student n = 12,240; 2014 student n = 11,931). Self-reported marijuana use, ease of access, and perceived harms were compared between years and by proximity of recreational marijuana stores to surveyed schools. Results: Adolescent marijuana use behaviors, wrongness of use, and perceptions of risk of harm were unchanged from baseline to one-year follow-up. Perceived ease of access to marijuana increased (from 46% to 52%). Proximity of recreational marijuana stores was not significantly associated with perceived ease of access to marijuana.

Conclusions/Importance: In the first study of adolescent marijuana use and perceptions after state retail implementation of recreational marijuana, there was little change in adolescent marijuana use but a significant change in perception of ease of access. Public health workers and policymakers should continue to monitor these changes as essential for evaluating the impact of liberalization of marijuana policies.     

The Relationship of Stress and Coping Methods to Adolescent Marijuana Use

As the use of marijuana among adolescents remains high, more effective interventions are needed. We conducted this cross-sectional survey at an outpatient, university-based, adolescent clinic to determine the prevalence of marijuana use in an inner-city adolescent population and to examine the relationship of stress and coping methods to marijuana user status (never user, experimenter, and frequent user). The subjects were 918 adolescents aged 12–21 years. Lifetime use in this population was 59% (n = 611) with 18.4% (n = 191) reporting frequent weekly use. Almost all (97%) marijuana users acknowledged marijuana use by friends. Stepwise logistic regression analysis showed that negative life events, greater use of the negative coping method of anger and less frequent use of the positive coping method of parental support were significantly and independently related to marijuana user status. In the presence of high peer use, exploring parent–child relationships and use of anger coping and intervening accordingly may decrease marijuana use.     

An Examination of Opinions Toward Marijuana Policies Among High School Seniors in the United States

Support for marijuana (cannabis) legalization is increasing in the US, and state-level marijuana policies are rapidly changing. Research is needed to examine correlates of opinions toward legalization among adolescents approaching adulthood as they are at high risk for use. Data were examined from a national representative sample of high school seniors in the Monitoring the Future study (years 2007-2011; N = 11,594) to delineate correlates of opinions toward legalization. A third of students felt marijuana should be entirely legal and 28.5% felt it should be treated as a minor violation; 48.0% felt that if legal to sell it should be sold to adults only, and 10.4% felt it should be sold to anyone. Females, conservatives, religious students, and those with friends who disapprove of marijuana use tended to be at lower odds for supporting legalization, and Black, liberal, and urban students were at higher odds for supporting more liberal policies. Recent and frequent marijuana use strongly increased odds for support for legalization; however, 16.7% of non-lifetime marijuana users also reported support for legalization. Findings should be interpreted with caution as state-level data were not available, but results suggest that support for marijuana legalization is common among specific subgroups of adolescents.     

Implications of Marijuana Legalization for Adolescent Substance Use

ABSTRACT. Marijuana that is legally available for adults has multiple implications for adolescent substance use. One potential effect that legalization may have is an increase in adolescent use to due increased availability, greater social acceptance, and possibly lower prices. Legalization may also facilitate the introduction of new formulations of marijuana (edible, vaporized) and with potentially higher potencies. It is unknown what adolescent consumption patterns will be if marijuana is widely available and marketed in different forms, or what effects different patterns of adolescent use will have on cognition, the development of marijuana use disorders, school performance, and the development of psychotic illnesses. Also unclear is whether adolescent users will be experiencing higher levels of tetrahydrocannabinol (THC) compared with previous generations of users due to higher potencies. Although previous studies of the effects of adolescent marijuana use provide some guidance for current policy and public health recommendations, many new studies will be needed that answer questions in the context of use within a legal adult environment. Claims that marijuana has medicinal benefits create additional challenges for adolescent prevention efforts, as they contrast with messages of its harmfulness. Prevention and treatment approaches will need to address perceptions of the safety of marijuana, claims of its medicinal use, and consider family-wide effects as older siblings and parents may increasingly openly consume and advocate for marijuana use. Guidance for primary care physicians will be needed regarded screening and counseling. Widespread legalization and acceptance of marijuana implies that as law enforcement approaches for marijuana control decline, public health, medical, and scientific efforts to understand and reduce negative consequences of adolescent marijuana use need to be substantially increased to levels commensurate with those efforts for tobacco and alcohol.     

Women’s perception of adolescent marijuana use in a hispanic seasonal farm worker community: A qualitative study

We examined the perception of adolescent children’s marijuana use and its consequences in the Hispanic seasonal farmworking community of South Florida via three focus groups with Hispanic adult female seasonal workers (n?=?29). The women described how adolescents’ marijuana use increased over the past five years. Social networks for marijuana use were reported near schools and bus stations. Although participants expressed concern over adolescent marijuana use and involvement in selling marijuana, they reported that their job demands preclude their ability to supervise their children. Participants do not report unlawful marijuana use due to fear of deportation.     

Implications of DSM-IV to DSM-5 Substance Use Disorder Diagnostic Changes in Adolescents Enrolled in a School-Based Intervention

ABSTRACT

This study aimed to examine (a) the impact of the change in the Diagnostic and Statistical Manual of Mental Disorders (DSM) from a categorical to dimensional classification of substance use diagnoses, (b) the elimination of the legal criterion, and (c) the inclusion of a craving criterion in the DSM-5. Specifically, we aimed to compare the differential diagnostic outcomes among high-risk substance-using adolescents enrolled in a school-based Motivational Enhancement Therapy (MET) intervention. We explored the alterations of diagnoses of adolescents in this sample and the prevalence of diagnostic promotions and demotions. We hypothesized that the dimensional approach of the DSM-5 would improve the utility of diagnosis in predicting severity of consequences and treatment outcomes in our sample. Method: Participants included 273 adolescents enrolled in a school-based intervention and were primarily male (76%) and Caucasian (47%), with 17% Asian/Pacific Islander, 17% Hispanic, 7% African-American, and 1% American Indian/Alaska Native. Results: We found that adolescents who lost diagnoses in the DSM-5 generally used substances less frequently and had fewer non-diagnostic negative consequences than those who remained consistently diagnosed across systems. Those who gained a diagnosis via the dimensional system tended to show higher use patterns and have more negative consequences than those who were never diagnosed. These findings indicate that the changes in the DSM are appropriate in this school-based clinical sample, at least in matching diagnostic status with substance use topography and negative consequences.     

Did marijuana legalization in Washington State reduce racial disparities in adult marijuana arrests?

Background: One justification for marijuana legalization has been to reduce existing disparities in marijuana-related arrests for African Americans. Objective: Describe changes in adult marijuana arrest rates and disparities in rates for African Americans in Washington State (WA) after legalization of possession of small amounts of marijuana for 21+ year olds in December 2012, and after marijuana retail market opening in July 2014. Methods: We used 2012–2015 National Incident Based Reporting System data to identify marijuana-related arrests. Negative binomial regression models were fit to examine monthly marijuana arrest rates over time, and to test for differences between African Americans and Whites, adjusting for age and sex. Results: Among those 21+ years old overall, marijuana arrest rates were dramatically lower after legalization of possession, and did not change significantly after the retail market opened. The marijuana arrest rates for African Americans did drop markedly and the absolute disparities decreased, but the relative disparities grew: from a rate 2.5 times higher than Whites to 5 times higher after the retail market opened. Among 18–20?year olds overall, marijuana arrest rates dropped, but not as dramatically as among older adults; the absolute disparities decreased, but the relative disparities did not change significantly. Conclusions: Marijuana arrest rates among both African American and White adults decreased significantly with legalization of possession, and stayed at a dramatically lower rate after the marijuana retail market opened. However, relative disparities in marijuana arrest rates for African Americans increased for those of legal age, and remained unchanged for younger adults.     

Personal Values as a Mediator of Relations Between Perceived Parental Support and Control and Youth Substance Use

Background: Tobacco and marijuana smoking are very popular in adolescence and there is a high rate of comorbidity between them, even in young adulthood. Parental support and control may hinder involvement in the use of these substances by promoting conventional values among adolescents. Objectives: The present study investigates the relations between family functioning (parental support and control) and psychoactive substance use (tobacco and marijuana smoking) and determines whether these relationships are mediated by personal values (in terms of disapproval of deviance and beliefs about the importance of school, health and religion). Methods: 175 Italian late adolescents (17 to 20 years old) participated in this two-wave longitudinal study. Data were collected at school through an anonymous questionnaire. Results: Greater parental control and support were directly associated with lower adolescent tobacco and marijuana use; adolescent acceptance of conventional values mediated the association between parenting and adolescent marijuana use. Conclusion: Findings emphasize the influence of family relationships throughout adolescence. The transmission of conventional values to adolescents may be a critical mechanism through which parenting protects adolescents from substance use, especially marijuana use.