Odds Of Marijuana Use Research Articles

The role of cancer in marijuana and prescription opioid use in the United States: A population-based analysis from 2005 to 2014.

For patients with cancer, marijuana may be an alternative to prescription opioid analgesics. This study analyzed self-reported marijuana and prescription opioid use among people with cancer over a 10-year time period. Population-based data sets from the US National Health and Nutrition Examination Survey between 2005 and 2014 were compiled for respondents aged 20 to 60years. Respondents with cancer and respondents without cancer were propensity score-matched (1:2) by demographics to compare substance use. Outcomes included current marijuana and prescription opioid use (ie, within the past 30days). Pearson chi-square tests and logistic regressions were performed; a 2-tailed P value<.05 was significant. There were 19,604 respondents, and 826 people with cancer were matched to 1652 controls. Among the respondents with cancer, 40.3% used marijuana within the past year, and 8.7% used it currently. Respondents with cancer were significantly more likely to use prescription opioids (odds ratio [OR], 2.43; 95% CI, 1.68-3.57; P<.001). Cancer was not associated with current marijuana use in a multivariable conditional logistic regression but was associated with current opioid use (OR, 1.82; 95% CI, 1.17-2.82; P=.008). Among all survey respondents, the odds of marijuana use significantly increased over time (OR, 1.05; 95% CI, 1.01-1.10; P=.012), whereas the odds of opioid use did not significantly change. There were no significant differences in the longitudinal odds of marijuana or opioid use over time between respondents with a cancer diagnosis and those without one. This population-based analysis revealed a considerable proportion of respondents with cancer self-reporting marijuana use (40.3%) and a significantly higher prevalence of opioid use among respondents with cancer. In the midst of an opioid epidemic, an evolving political landscape, and new developments in oncology, quantifying the prevalence of opioid and marijuana use in the US population, especially among patients with cancer, is particularly relevant. Although opioid use did not significantly change from 2005 to 2014 among all respondents, marijuana use did increase, likely reflecting increased availability and legislative changes. A cancer diagnosis did not significantly affect longitudinal opioid or marijuana use.

Marijuana risk perceptions are associated with past-month marijuana use among Black first-year college students at a historically Black university

To examine the relationship between marijuana risk perceptions and marijuana use, and assess the potential moderating role of stress among Black students from a historically Black university, a convenience sample of students (n = 213) was surveyed. The majority (87.9%) of the sample was Black and 52% were female. Over a third (35.1%) reported past 30-day marijuana use, and a majority (58.4%) reported no or slight risk from using marijuana once or twice weekly. Higher marijuana risk perceptions were associated with lower odds of marijuana use (OR = .45, 95% CI [0.32, 0.64]). No significant relationship between stress and marijuana use was found. Perception of marijuana risk warrants further examination as a predictor of marijuana use.

Ecological momentary assessment of various tobacco product use among young adults

IntroductionYoung adults are at high risk for using traditional and novel tobacco products. However, little is known about daily/weekly use patterns or psychosocial triggers for using various tobacco products. MethodsThis ecological momentary assessment (EMA) study examined timing, tobacco cravings, affect, social context, and other substance use (alcohol, marijuana) in relation to use of cigarettes, electronic nicotine delivery systems (ENDS), and any tobacco product (i.e., cigarettes, ENDS, cigars, hookah), respectively. We also examined interactions between these predictors, sex, and race/ethnicity. From a longitudinal study of 3418 18–25 year-olds from seven Georgia colleges/universities, we recruited 72 reporting current tobacco use to participate in the 21-day EMA study; 43 participated, of which 31 completed ≥66% assessments and were analyzed. Cravings, affect, social context, and substance use were assessed daily across four four-hour windows. ResultsOf the 31 participants, average age was 21.10 years (SD = 1.95), 45.2% were female, and 71.0% non-Hispanic White; 71.0% used cigarettes, 58.1% ENDS, 38.7% cigars, and 25.8% hookah (25.6% used one product, 46.5% two, 27.9% ≥ three). Predictors of cigarette use included higher anxiety, greater odds of marijuana and alcohol use, and higher boredom levels among women. Predictors of ENDS use included being non-White and greater odds of marijuana use, as well as higher tobacco cravings among women and higher boredom among men. Predictors of any tobacco product use included being non-White, higher boredom levels, and greater odds of marijuana and alcohol use. ConclusionsDistinct interventions may be needed to address use of differing tobacco products among young adults.

The Clinical Relevance of Divergence in Adolescent-Parent Reports of Adolescent Depression and Anxiety.

This study examines associations between adolescent problem behaviors and adolescent-parent disagreement in ratings of adolescent depression and anxiety symptoms. Adolescent-parent dyads (N = 463; mean age = 12.68 years; 48.5% female; 78.2% White and 21.8% non-White) reported on adolescent depression and anxiety using parallel scales from the Youth Self Report (Achenbach et al., J Emot Behav Disord 10:194-203, 2002) and the Child Behavior Checklist (Achenbach and Rescorla, The manual for the ASEBA school-age forms & profiles, University of Vermont, Research Center for Children, Youth, and Families, Burlington, 2001) across four waves. Generalized estimating equations were used to examine the relationship between discrepancy scores and adolescent behavioral outcomes: incidence of adolescent past-year substance use (alcohol use, binge drinking, marijuana use, and nonmedical use of controlled medications), delinquency, self-harm behavior, and aggression. Findings showed that larger adolescent-parent divergence scores of depression were associated with higher odds of marijuana use, non-medical use of controlled medications, alcohol use, binge drinking, in-school delinquency, illegal behavior, self-harm behavior, and clinically significant levels of aggressive behavior. Results further revealed that larger divergence scores on anxiety were associated with higher odds of in-school delinquency, illegal behavior, self-harm behavior, and clinically significant levels of aggressive behavior. Adolescent-parent reporting discrepancy on adolescent's depression and anxiety symptoms may be indicative of adolescent's social, emotional, and behavioral problems, and the disagreement may signal further need for assessment of the adolescent.

Dating violence victimization and substance use: The role of a serotonin transporter gene polymorphism (5HTTLPR)

While there is developing research on how genes moderate the effect of stressful life events on substance use, the limited research has yet to focus on specific stressors. As adolescent dating violence victimization has been linked to various substance use behaviors, the current research seeks to further examine the longitudinal outcomes of adolescent dating violence victimization and the role that genes play in moderating these effects. Specifically, using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a series of logistic and negative binomial regressions are run to analyze the direct and interactive effects of adolescent dating violence victimization and a polymorphism (5HTTLPR) in the promoter region of the serotonin transporter gene on both alcohol use problems and marijuana use. The results find that 5HTTLPR interacts with adolescent dating violence victimization to increase odds of marijuana use for the sample. However, the interaction between 5HTTLPR and adolescent dating violence has differential effects for males and females, suggesting sex differences regarding the susceptibility properties of 5HTTLPR. Implications of these findings are discussed.

Psychometric evaluation of an abbreviated version of the intragroup marginalization inventory

ABSTRACTTobacco and marijuana use among U.S. young adults is a top public health concern, and racial/ethnic minorities may be at particular risk. Past research examining cultural variables has focused on the individual in relation to the mainstream U.S. culture; however, an individual can also experience within-group stress, or intragroup marginalization. We used the 2014 San Francisco Bay Area Young Adult Health Survey to validate an abbreviated measure of intragroup marginalization and identify associations between intragroup marginalization and tobacco and marijuana use among ethnic minority young adults (N = 1,058). Exploratory factor analysis was conducted to identify factors within the abbreviated scale, and logistic regressions were conducted to examine relationships between intragroup marginalization and tobacco and marijuana use. Two factors emerged from the abbreviated scale. The first factor encompassed items related to belonging and membership, capturing whether individuals experienced marginalization due to not fitting in because of physical appearance or behavior. The second factor encompassed whether individuals shared similar hopes and dreams to their friends and family members. Factor 1 (membership) was associated with increased odds of marijuana use (OR = 1.34, p < .05) and lower odds of using cigars (OR = 0.79, p < .05), controlling for sociodemographic factors. Results suggest that young adults may use marijuana as a means to build connection and belonging to cope with feeling marginalized. Health education programs focused on ethnic minority young adults are needed to help them effectively cope with intragroup marginalization without resorting to marijuana use.

School Protective Factors and Substance Use Among Lesbian, Gay, and Bisexual Adolescents in California Public Schools.

The majority of studies examining substance use among lesbian, gay, and bisexual (LGB) youth have focused on a wide array of risk factors (e.g., victimization). Few studies have explored the protective role of schools. This study aims to fill this gap in the literature and inform programs aimed at reducing substance use among LGB youth. More specifically, this study explores the extent to which school connectedness and support from teachers and other adults at school are associated with substance use among LGB youth in school and within the past 30 days. A secondary analysis of the 2013-2015 California Healthy Kids Survey (CHKS) was conducted to examine associations between school protective factors (i.e., school connectedness and adult support) and substance use among LGB youth, above and beyond a key risk factor, school victimization. The study outcomes were past 30-day and in-school use of cigarettes, alcohol, marijuana, inhalants, prescription pain medication, and other illegal drugs. Overall, school connectedness and school adult support were associated with lower odds of substance use. For example, higher levels of school connectedness were associated with 22% decreased odds of past 30-day inhalant use (adjusted odds ratio [AOR] = 0.78; 95% confidence interval [CI] = 0.72-0.86), and 25% decreased odds of past 30-day prescription pain medication use (AOR = 0.75; 95% CI = 0.69-0.82). Higher levels of adult support in school were also associated with 17% decreased odds of marijuana use on school property in the past 30 days (AOR = 0.83; 95% CI = 0.77-0.91). The results indicate a need for substance use prevention programs that integrate school connectedness and adult support in school.

Gender Differences in Relations among Perceived Family Characteristics and Risky Health Behaviors in Urban Adolescents.

Research regarding the role of gender in relations between family characteristics and health risk behaviors has been limited. This study aims to investigate gender differences in associations between family processes and risk-taking in adolescents. Adolescents (N=249; mean age=14.5years) starting their first year at an urban high school in the northeastern USA completed self-report measures that assessed family characteristics (i.e., parental monitoring, family social support, family conflict) and health behaviors (i.e., tobacco use, alcohol use, marijuana use, sex initiation) as part of a prospective, community-based study. Multivariate logistic regression models were used to investigate gender differences in associations between the family characteristics and health behaviors. Among males, higher levels of perceived parental monitoring were associated with lower odds of using tobacco and having ever engaged in sex. Among females, higher levels of perceived parental monitoring were associated with lower odds of marijuana use, alcohol use, and having ever engaged in sex. However, in contrast to males, among females (a) higher levels of perceived family social support were associated with lower odds of alcohol use and having ever engaged in sex and (b) higher levels of perceived family conflict were associated with higher odds of marijuana use and having ever engaged in sex. Family processes were more strongly related to health behaviors among adolescent females than adolescent males. Interventions that increase parental monitoring and family social support as well as decrease family conflict may help to protect against adolescent risk taking, especially for females.

The Prospective Association Between Sleep and Initiation of Substance Use in Young Adolescents

PurposeThis study aimed to determine the unique utility of poor sleep health in predicting the onset of substance use in adolescents. MethodsMiddle school students (N = 829, mean (M)age = 12.6 years, 52% female, 73% white) who participated in an ongoing prospective study of alcohol onset and progression completed a set of Web-based health behavior surveys over a 4-year period, with recruitment beginning in 2009. Surveys included assessments of alcohol, cigarette, and marijuana use as well as sleep duration, bedtime delay (from weekdays to weekends), and daytime sleepiness. Data were analyzed using discrete-time Cox Proportional hazard's regression. ResultsControlling for participant age at sleep assessment, gender, and internalizing and externalizing behaviors, shorter sleep duration and greater daytime sleepiness in year 1 were associated with increased odds of having had a full drink of alcohol, having engaged in heavy episodic drinking, and having experienced alcohol-related consequences by year 4. Shorter sleep duration was also associated with increased odds of marijuana use by year 4. No sleep parameter was uniquely associated with increased odds of cigarette use (first puff or first full cigarette). Effects were evident for both males and females. Age at sleep assessment did not moderate effects. ConclusionsSleep health is a prospective predictor of the onset of alcohol and marijuana use among adolescents. Increased efforts to prevent and intervene in sleep problems among adolescents are warranted.

The Association Between Marijuana Usage and Discrimination Among Adult Black Men.

Black men may use marijuana as an externalizing coping mechanism to handle the chronic stress of discrimination. The aim of the study was to examine the relationship between everyday and major discrimination and marijuana use among a national sample of Black men. Using the National Survey of American Life, logistic regression analyses was used to determine the association between recent marijuana use and everyday discrimination, major discrimination, and a fully adjusted model that include everyday and major discrimination among adult Black men ( n = 1,833). Additionally, a multinomial logistic regression was used to examine the association between the frequency of marijuana usage and everyday discrimination and major discrimination among men who used marijuana in the past year. Everyday discrimination was not associated with marijuana use. In the fully adjusted model, men who experienced major discrimination had a higher odds of marijuana use ( OR: 1.19, 95% CI [1.05, 1.34]), than those who did not control for everyday discrimination and covariates of interest. Among recent marijuana users, men who used almost every day had a decreased risks for major discrimination (RRR: 0.72, 95% CI [0.56, 0.92]), compared with men who used less than once a month. The findings suggest that recent marijuana use among Black men is associated with experiences of major discrimination. Interestingly, men who used almost every day had a decreased risk for major discrimination. Marijuana may be used as a coping mechanism.

Characterizing substance use and mental health profiles of cigar, blunt, and non-blunt marijuana users from the National Survey of Drug Use and Health

BackgroundSmoking marijuana in a cigar (blunt use) is gaining popularity in the U.S. Research suggests that blunt users differ from exclusive cigar or marijuana users on a variety of demographic and substance use factors. Misreporting of blunts and cigars is also common, particularly among young people, and may lead to inaccurate prevalence estimates. To determine subtype differences, this study investigated the prevalence and demographic, mental health, and substance use correlates of four mutually-exclusive groups of blunt, cigar, and marijuana past 30-day users (cigar-only, blunt-only, non-blunt marijuana, or dual cigar-blunt). MethodData were analyzed from the 2013 National Survey of Drug Use and Health. ResultsIn weighted multinomial logistic regression models, respondents who were younger, Black, and who had used tobacco, alcohol, or other drugs in the past 30-days had the highest odds of reporting blunt-only or dual cigar-blunt use. Those reporting blunt-only and dual cigar-blunt use also endorsed a greater number of marijuana and alcohol use disorder symptoms compared to those reporting cigar-only and non-blunt marijuana use. Lower marijuana risk perceptions were associated with increased odds of marijuana use with or without blunts. Major depressive episode was uniquely associated with non-blunt marijuana use. With respect to misclassifiers, respondents who reported past 30-day blunt use but not past 30-day marijuana use were younger, Black, female, and had lower education and income. DiscussionThose who report blunt-only and dual cigar-blunt use showed the most severe risk profiles. Communicating health consequences and risks of blunt use should be directed toward specific subgroups.

Daily Reports of Positive and Negative Affect and Alcohol and Marijuana Use Among College Student and Nonstudent Young Adults

ABSTRACTBackground: Daily affect and substance use covary among college students, but little is known about these associations among young adults not in college. Objectives: The current pilot study examines associations between positive and negative affect and alcohol and marijuana use, with a focus on differences between college student and nonstudent young adults. Methods: High school seniors completed a baseline survey during the spring of 2012 and were then randomly selected to participate in an intensive measurement follow-up. Participants in the follow-up (N = 72, 40.3% men, 77.8% White, 66.7% full-time college students) completed up to 14 consecutive web-based daily surveys during the fall after high school completion. Multilevel models in which days (Level 1) were nested in persons (Level 2) were estimated. Results: Weekend days were associated with increased alcohol use among all young adults, increased marijuana use among college students, and decreased marijuana use among nonstudents. For young adults not in college, greater daily positive affect was associated with increased likelihood of binge drinking, consuming a greater number of drinks, and lower odds of marijuana use; greater daily negative affect was associated with lower odds of alcohol use and lower odds of binge drinking for non-students. For college students, greater daily negative affect was associated with lower odds of marijuana use. Conclusions/Importance: Daily affect and alcohol and marijuana use covary among young adults, though these associations differ between students and non-students. Results highlight the need to examine predictors of alcohol and marijuana use among young adults who do not attend college.

Patterns of cannabis use in patients with Inflammatory Bowel Disease: A population based analysis

BackgroundTobacco use patterns and effects in patients with Inflammatory Bowel Disease have been extensively studied, however the role and patterns of cannabis use remains poorly defined. Our aim was to evaluate patterns of marijuana use in a large population based survey. MethodsCases were identified from the NHANES database from the National Center for Health Statistics for the time period from January, 2009 through December, 2010 as having ulcerative colitis or Crohn's disease, and exact matched with controls using the Propensity Score Module of SPSS, based on age, gender, and sample weighted using the nearest neighbor method. ResultsAfter weighting, 2084,895 subjects with IBD and 2013,901 control subjects were identified with no significant differences in demographic characteristics. Subjects with IBD had a higher incidence of ever having used marijuana/hashish (M/H) (67.3% vs. 60.0%) and an earlier age of onset of M/H use (15.7 years vs. 19.6 years). Patients with IBD were less likely to have used M/H every month for a year, but more likely to use a heavier amount per day (64.9% subjects with IBD used three or more joints per day vs. 80.5% of subjects without IBD used two or fewer joints per day). In multivariable logistic regression, presence of IBD, male gender, and age over 40 years predicted M/H use. ConclusionOur study is the first to evaluate marijuana patterns in a large-scale population based survey. Older, male IBD patients have the highest odds of marijuana use.

Out-of-School Time and Adolescent Substance Use

PurposeHigh levels of adolescent substance use are linked to lower academic achievement, reduced schooling, and delinquency. We assess four types of out-of-school time (OST) contexts—unsupervised time with peers, sports, organized activities, and paid employment—in relation to tobacco, alcohol, and marijuana use at the end of high school. Other research has examined these OST contexts in isolation, limiting efforts to disentangle potentially confounded relations. MethodsLongitudinal data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (N = 766) examined associations between different OST contexts during high school and substance use at the end of high school. ResultsUnsupervised time with peers increased the odds of tobacco, alcohol, and marijuana use, whereas sports increased the odds of alcohol use and decreased the odds of marijuana use. Paid employment increased the odds of tobacco and alcohol use. Unsupervised time with peers predicted increased amounts of tobacco, alcohol, and marijuana use, whereas sports predicted decreased amounts of tobacco and marijuana use and increased amounts of alcohol use at the end of high school. ConclusionsAlthough unsupervised time with peers, sports, and paid employment were differentially linked to the odds of substance use, only unsupervised time with peers and sports were significantly associated with the amounts of tobacco, alcohol, and marijuana use at the end of high school. These findings underscore the value of considering OST contexts in relation to strategies to promote adolescent health. Reducing unsupervised time with peers and increasing sports participation may have positive impacts on reducing substance use.

The effect of perceived risk on the combined used of alcohol and marijuana: Results from daily surveys

BackgroundStudies looking at the association between perceived risk and simultaneous use of alcohol and marijuana are scarce. The present study has three purposes: (1) to examine the association between alcohol and marijuana use at the daily level; (2) to document how this association varies by the perceived risk of using alcohol and marijuana simultaneously; (3) to test whether the association varies by college attendance. Methods89 young adults (Mean Age=18.3years, SD=0.5) participated between October 2012 and May 2013. Participants completed a 30-min survey followed by 14 brief daily surveys in each of three waves. ResultsAlcohol use on a given day was associated with increased odds of marijuana use that day, especially among young adults with lower perceived risk. For college students, the association between alcohol and marijuana was weaker than for non-students. ConclusionsAlcohol and marijuana use were associated at a daily level, especially among young adults with lower perceived risk and those who were not attending college.

Cyclic vomiting presentations following marijuana liberalization in Colorado.

Case reports have described a syndrome of cyclic vomiting associated with chronic marijuana use, termed cannabinoid hyperemesis syndrome. The primary objective was to determine the prevalence of patients presenting with cyclic vomiting before and after the liberalization of medical marijuana in Colorado in 2009. The secondary objective was to describe the odds of marijuana use among cyclic vomiting visits in these same time periods. This was a cross-sectional study of cyclic vomiting visits to the emergency department (ED) before and after marijuana liberalization. ED visits with International Classification of Diseases, ninth revision, coding for cyclic vomiting or that met diagnostic criteria for cyclic vomiting by the Rome III criteria were included. The authors reviewed 2,574 visits and identified 36 patients diagnosed with cyclic vomiting over 128 visits. The prevalence of cyclic vomiting visits increased from 41 per 113,262 ED visits to 87 per 125,095 ED visits after marijuana liberalization, corresponding to a prevalence ratio of 1.92 (95% confidence interval [CI]=1.33 to 2.79). Patients with cyclic vomiting in the postliberalization period were more likely to have marijuana use documented than patients in the preliberalization period (odds ratio= 3.59, 95% CI=1.44 to 9.00). The prevalence of cyclic vomiting presentations nearly doubled after the liberalization of medical marijuana. Patients presenting with cyclic vomiting in the postliberalization period were more likely to endorse marijuana use, although it is unclear whether this was secondary to increased marijuana use, more accurate marijuana reporting, or both.

Menthol Cigarette and Marijuana Use Among Adolescents

Menthol cigarette and marijuana use among adolescents is high; however, little is known about dual use in this age. Thus, we examined these rates among 2 samples of adolescents in Connecticut. Study 1 examined a school-wide survey assessing variables related to cigarettes and marijuana among high school students (N = 837 [13% smokers]), and Study 2 examined these factors using baseline data of high school-aged, treatment-seeking, daily cigarette smokers prior to quitting (N = 132). In Study 1, lifetime marijuana use among all adolescents was 33% and past 30-day marijuana use was 21%. Among cigarette smokers, 55% reported smoking menthol cigarettes, 84% reported lifetime marijuana use, and 66% reported past 30-day marijuana use. Multivariate-adjusted logistic regression models indicated that cigarette smokers, when compared with nonsmokers, had greater rates of lifetime (odds ratio [OR] = 10.91) and past 30-day marijuana use (OR = 10.44). Among smokers, use of menthol cigarettes, when compared with use of nonmenthol cigarettes, was associated with greater lifetime (OR = 5.05) but not past 30-day marijuana use. In Study 2 with daily smokers, 59% of adolescents reported use of menthol cigarettes and 66% reported past 30-day marijuana use. Compared with nonmenthol cigarette smokers, menthol cigarette smokers were more likely to report past 30-day marijuana use (OR = 2.44). Cigarette smoking is associated with marijuana use, and among smokers, menthol cigarette smoking further increased the odds of marijuana use. More research on the dual use of marijuana and tobacco is needed to inform prevention and treatment of substance use.

Illicit and nonmedical drug use among Asian Americans, Native Hawaiians/Pacific Islanders, and mixed-race individuals

BackgroundThe racial/ethnic composition of the United States is shifting rapidly, with non-Hispanic Asian-Americans, Native Hawaiians/Pacific Islanders (NHs/PIs), and mixed-race individuals the fastest growing segments of the population. We determined new drug use estimates for these rising groups. Prevalences among Whites were included as a comparison. MethodsData were from the 2005–2011 National Surveys on Drug Use and Health. Substance use among respondents aged ≥12 years was assessed by computer-assisted self-interviewing methods. Respondents’ self-reported race/ethnicity, age, gender, household income, government assistance, county type, residential stability, major depressive episode, history of being arrested, tobacco use, and alcohol use were examined as correlates. We stratified the analysis by race/ethnicity and used logistic regression to estimate odds of drug use. ResultsPrevalence of past-year marijuana use among Whites increased from 10.7% in 2005 to 11.6–11.8% in 2009–2011 (P<0.05). There were no significant yearly changes in drug use prevalences among Asian-Americans, NHs/PIs, and mixed-race people; but use of any drug, especially marijuana, was prevalent among NHs/PIs and mixed-race people (21.2% and 23.3%, respectively, in 2011). Compared with Asian-Americans, NHs/PIs had higher odds of marijuana use, and mixed-race individuals had higher odds of using marijuana, cocaine, hallucinogens, stimulants, sedatives, and tranquilizers. Compared with Whites, mixed-race individuals had greater odds of any drug use, mainly marijuana, and NHs/PIs resembled Whites in odds of any drug use. ConclusionsFindings reveal alarmingly prevalent drug use among NHs/PIs and mixed-race people. Research on drug use is needed in these rising populations to inform prevention and treatment efforts.

Medical marijuana laws in 50 states: Investigating the relationship between state legalization of medical marijuana and marijuana use, abuse and dependence

Background Marijuana is the most frequently used illicit substance in the United States. Little is known of the role that macro-level factors, including community norms and laws related to substance use, play in determining marijuana use, abuse and dependence. We tested the relationship between state-level legalization of medical marijuana and marijuana use, abuse, and dependence. Methods We used the second wave of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a national survey of adults aged 18+ ( n = 34,653). Selected analyses were replicated using the National Survey on Drug Use and Health (NSDUH), a yearly survey of ∼68,000 individuals aged 12+. We measured past-year cannabis use and DSM-IV abuse/dependence. Results In NESARC, residents of states with medical marijuana laws had higher odds of marijuana use (OR: 1.92; 95% CI: 1.49–2.47) and marijuana abuse/dependence (OR: 1.81; 95% CI: 1.22–2.67) than residents of states without such laws. Marijuana abuse/dependence was not more prevalent among marijuana users in these states (OR: 1.03; 95% CI: 0.67–1.60), suggesting that the higher risk for marijuana abuse/dependence in these states was accounted for by higher rates of use. In NSDUH, states that legalized medical marijuana also had higher rates of marijuana use. Conclusions States that legalized medical marijuana had higher rates of marijuana use. Future research needs to examine whether the association is causal, or is due to an underlying common cause, such as community norms supportive of the legalization of medical marijuana and of marijuana use.

The social norms of birth cohorts and adolescent marijuana use in the United States, 1976–2007

Studies of the relationship between social norms and marijuana use have generally focused on individual attitudes, leaving the influence of larger societal-level attitudes unknown. The present study investigated societal-level disapproval of marijuana use defined by birth cohort or by time-period. Combined analysis of nationally representative annual surveys of secondary school students in the United States conducted from 1976 to 2007 as part of the Monitoring the Future study. In-school surveys completed by adolescents in the United States. A total of 986 003 adolescents in grades 8, 10 and 12. Main predictors included the percentage of students who disapproved of marijuana in each birth cohort and time-period. Multi-level models with individuals clustered in time-periods of observation and birth cohorts were modeled, with past-year marijuana use as the outcome. Results indicated a significant and strong effect of birth cohort disapproval of marijuana use in predicting individual risk of marijuana use, after controlling for individual-level disapproval, perceived norms towards marijuana and other characteristics. Compared to birth cohorts in which most (87-90.9%) adolescents disapproved of marijuana use, odds of marijuana use were 3.53 times higher in cohorts where fewer than half (42-46.9%) disapproved (99% confidence interval: 2.75, 4.53). Individuals in birth cohorts that are more disapproving of marijuana use are less likely to use, independent of their personal attitudes towards marijuana use. Social norms and attitudes regarding marijuana use cluster in birth cohorts, and this clustering has a direct effect on marijuana use even after controlling for individual attitudes and perceptions of norms.