Increased Marijuana Use Research Articles

Employment and Marijuana Use Among Washington State Adolescents Before and After Legalization of Retail Marijuana

PurposeThe purpose of the study was to describe associations between employment and marijuana use among adolescents 2 years before passage of 2012 ballot initiative and 2 years after the implementation of retail recreational marijuana sales took place in Washington. MethodsWe used 2010 and 2016 data from Washington's statewide school-based Healthy Youth Survey, which is completed by more than 76,000 youth annually and representative of 8th, 10th, and 12th graders in public schools. We used “difference-in-differences” regression to estimate the odds of current, past 30-day marijuana use by working status and hours worked per week compared with nonworking youth. ResultsWorking adolescents in all grades had higher prevalence of recent marijuana use compared with nonworking adolescents. Youth working in formal settings, such as retail and service sectors, were more likely to use marijuana than nonworking and youth working in informal settings, such as babysitting. Between 2010 and 2016, marijuana use decreased significantly among working and nonworking 8th and 10th graders. Among working 12th graders, marijuana use increased significantly over time relative to nonworking youth (adjusted odds ratio: 1.34, 95% confidence interval: 1.22–1.48). Associations were stronger for youth who worked more hours per week. ConclusionsWorking youth were more likely to use marijuana before and after Washington's legalization of retail marijuana. Legalization was associated with increases in marijuana use specifically among 12th-grade working youth. States legalizing marijuana may consider implementing interventions to support healthy behaviors among working youth.

Neighborhood context and transitions in marijuana use among urban young adults

Background: In emerging adulthood when many youth are maturing out of marijuana use, Blacks continue to have high rates of use and disorder. Theory suggests that factors tied to neighborhood disadvantage may partially explain this phenomenon but research is limited. Objectives: This study examines the influence of neighborhood physical and social disorder on transitions in marijuana use during emerging adulthood in a low-income urban sample. Methods: 379 primarily Black young adults residing in low-income neighborhoods in Baltimore City were followed-up annually from ages 18 to 21. Neighborhood environment was evaluated using a valid and reliable field-rater assessment of the residential block. Longitudinal latent class and latent transition analyses were performed. Results: Fit indices supported three-classes of marijuana use: no use, infrequent use and frequent use. Between ages 18 and 21, young adults tended to transition toward lower levels of use. However, neighborhood physical disorder was associated with transitioning to increased marijuana use (no use to frequent use; AOR = 2.712; p = .023) while positive neighborhood social activity was associated with a decreased risk (AOR = 0.002; p = .013). Neighborhood social activity was also associated with decreases in use (frequent to infrequent use; AOR = 2.342; p = .020). Conclusions/Importance: These findings demonstrate that physical disorder within the context of a low-income urban neighborhood adversely impacts marijuana use. However, even in the presence of physical disorder, interventions that foster collective efficacy among residents through positive social activity may prevent initiation and progression of marijuana use.

Increasing marijuana use for black adolescents in the United States: A test of competing explanations

AimsIn the last decade the relatively lower levels of marijuana use for black relative to non-black high school seniors has grown smaller and disappeared, drawing to a close a unique disparity that actually favored a disadvantaged group for at least thirty years. In this study we test trends in cigarette smoking and religiosity as possible explanations for this closing disparity. The study also examines whether increasing marijuana levels for black adolescents is better characterized as a cohort effect or an historical period effect. DesignAnalyses use relative risk regression and focus on data from yearly, cross-sectional surveys from the time period 2008–2017. Setting and participantsData comes from the nationally-representative Monitoring the Future survey, which conducts in-school surveys of secondary school students. The analysis uses data from 114,552 high school seniors (in 12th grade), 123,594 in 10th grade, and 136,741 in 8th grade. FindingsPast 12-month marijuana prevalence significantly increased for black as compared to non-black adolescents from 2008 to 2017 in 12th grade, 10th grade, and 8th grade. The increase attenuated by more than half and was not statistically significant after adjusting for cigarette smoking. In contrast, the increase was little changed after adjusting adolescent levels of religiosity. The increase is better characterized as a cohort effect than a period effect. ConclusionsThese results support the increase in marijuana use for black relative to non-black adolescents as an unexpected consequence of the great decline in adolescent cigarette smoking, which has occurred slower for black adolescents.

Marijuana use among adolescents is associated with deleterious alterations in mature BDNF.

BackgroundWith increases in marijuana use and legalization efforts, it is imperative to establish its impact on the developing brain. Therefore, we investigated whether exposure to marijuana alters brain derived neurotropic-factor (BDNF), given its critical role in brain development and plasticity. We then examined whether onset age of cannabis use was associated with more severe changes. A single site, cohort study following 500 urban healthy American adolescents. Changes in plasma m-BDNF levels were longitudinally assessed, and a multi-method approach was implemented to ascertain marijuana use. Multivariate and general linear model (GLM) regression modeling were utilized to test the main hypothesis, controlling for confounders.ResultsGroup-based trajectory modeling identified four distinct groups, characterized by naive (60% control), starters (14%), chronic users (20%), and experimenting/quitters (6%). Compared to controls, those initiating marijuana use had similar pre-existent m-BDNF (1939.2 ± 221 vs. 2640.7 ± 1309 ng/ml, p=0.4) After adjusting for confounding factors, GLM analyses revealed that, compared to controls, younger adolescents increased BDNF levels when experimenting and during moderate marijuana use. Older adolescents had a steeper increase in endogenous BDNF levels, particularly when escalating use. Multivariate analyses confirmed marijuana use as a predictor of m-BDNF (p = 0.001).ConclusionsThis is the first study demonstrating BDNF alterations were not a precondition. Rather, BDNF alteration was secondary to marijuana use, serving as cautionary evidence of marijuana's deleterious effects. Findings suggest that when marijuana use escalates, the BDNF pathway becomes more deregulated. Analyses confirm that age of marijuana use onset influences the magnitude of these changes.

The Covert Inducer: Narrative Commentary of Marijuana in the 21st Century and its Connection to Psychological Disorders

Research into Cannabis induced psychosis and marijuana’s effect on pre-existing mental disorders has been underway for several decades. However, many of these findings have surfaced in the U.S. over the last 15 years. Most of the information includes endogenous cannabinoid receptors in the brain, facts recently discovered, and more scientific evidence is needed to fully understand their role in Cannabis induced psychosis. Because cannabinoid receptors are neuromodulators, neurotransmitters are involved and how these are affected has yet to be discovered. Based on current understanding of neurotransmitters, the central nervous system, and mental disorders, this narrative review explores possible mechanisms of Cannabis induced mental disorders from a toxicological, pharmacological, and psychological perspective. This review also discusses the myth that no long-term ailments or illnesses arise from Cannabis use. It also illustrates why it is important to consider the potential consequences of legalizing Cannabis due to costly impacts on society with respect to public health and safety. Additionally, the author shares an experience observing an individual suffering from a mental disorder whose increased marijuana use led to more frequent, and dangerous, manic episodes.

The Longitudinal Associations Between Outness and Health Outcomes Among Gay/Lesbian Versus Bisexual Emerging Adults.

Sexual minorities are at increased risk for substance use and mental health problems. Although previous studies have examined the associations between outness and health outcomes, few have used longitudinal designs or examined differences across subgroups of sexual minorities. To address these gaps, the current study examined sexual orientation and gender as moderators of the longitudinal associations between outness and substance use (cigarettes, marijuana, illicit drugs, and alcohol) and mental health (depression and anxiety). Data were from a sample of 169 sexual minority emerging adults (98 women and 71 men) who provided self-report data at four times over 3.5years. Results indicated that sexual orientation moderated the within-person associations between outness and changes in health. For bisexual individuals, being more out was associated with increases in marijuana use, illicit drug use, and depression. In contrast, for gay/lesbian individuals, being more out was associated with decreases in illicit drug use and it was not significantly associated with changes in marijuana use or depression. Additionally, outness was not significantly associated with changes in cigarette use, alcohol use, or anxiety for gay/lesbian or bisexual individuals, and gender did not moderate any of the associations. In sum, being more open about one's sexual orientation had negative consequences for bisexual individuals but not for gay/lesbian individuals. Professionals who work with sexual minorities need to be aware of the potential risks of being open about one's sexual orientation for bisexual individuals. Interventions are needed to facilitate disclosure decisions and to promote the health of sexual minorities.

Marijuana Use and Depressive Symptoms; Gender Differences in African American Adolescents.

Introduction: This study aimed to examine gender differences in the bidirectional associations between marijuana use and depressive symptoms among African American adolescents. The study also tested gender differences in the effects of socioeconomic status, maternal support, and friends’ drug use on adolescents’ depressive symptoms and marijuana use.Methods: This is a secondary analysis of the Flint Adolescent Study (FAS). Six hundred and eighty one African American adolescents (335 males and 346 females) were followed for 3 years, from 1995 (mean age 16) to 1997 (mean age 19). Depressive symptoms (Brief Symptom Inventory) and marijuana use were measured annually during the follow up. We used multi-group latent growth curve modeling to explore the reciprocal associations between depressive symptoms and marijuana use over time based on gender.Results: Baseline marijuana use was predictive of an increase in depressive symptoms over time among male but not female African American adolescents. Baseline depressive symptoms were not predictive of an increase in marijuana use among male or female adolescents.Conclusion: Study findings suggest that male African American adolescents who use marijuana are at an increased risk of subsequent depressive symptoms. Interventions that combine screening and treatment for marijuana use and depression may be indicated for African American male adolescents.

OLDER ADULTS DRIVING UNDER THE INFLUENCE: ASSOCIATIONS WITH MARIJUANA USE AND RISK PERCEPTIONS

Despite increasing marijuana use among older adults, little research has been done on marijuana’s impact on their driving under the influence (DUI). Using the 2013 to 2014 National Survey on Drug Use and Health (NSDUH) data, this study examined the association of older adults’ (N=15,302, aged 50+) self-reported DUI with marijuana use, marijuana use disorder, and marijuana risk perception. All analyses were conducted with Stata/MP 14’s svy function to account for NSDUH’s complex sampling design. The findings show that 10.75% of the 50–64 age group and 4.12% of the 65+ age group reported DUI in the past year. Of all 50+-year olds, 4.0% of those who did not reported DUI reported past-year marijuana use, but 22.9% of those who reported DUI reported marijuana use (p<.001). Logistic regression analysis showed that marijuana users were seven times more likely to report DUI than nonusers controlling for alcohol use disorder, other illicit drug use, and sociodemographic and health/mental health statuses (adjusted odds ratio [AOR]=7.01, 95% confidence interval [CI]=5.00–9.80). Among marijuana users, those with marijuana use disorder were more likely than those without the disorder to report DUI, controlling for the same factors (AOR=2.63; 95% CI=1.03–6.68). Perception of moderate/great risk of marijuana use 1–2 times a week decreased the odds of DUI report (AOR=0.71; 95% CI=0.57–0.88). As safe driving is key to prolonging independence in late life, older marijuana users need education on the risk of marijuana use, alone and with other substances, on their driving capacity and age-appropriate treatment for marijuana use disorder.

Survey shows decrease in opioid usage, increase in marijuana use

Opioid usage was down in 2017 compared to prior years, but usage of marijuana — particularly among Americans aged 18 to 25 — had increased in 2017 over prior years, according to a study from the National Survey on Drug Use and Health. In 2017, approximately 11.4 million people misused opioids, with nearly 60 percent indicating that the main reason they misused opioids was to combat physical pain. That number represents half as many Americans trying opioids in 2017 as they did in 2016.

Prenatal tobacco and marijuana co-use: Impact on newborn neurobehavior

Tobacco and marijuana are some of the most common prenatal substance exposures worldwide. The social acceptability and political landscape of marijuana and its potency have changed dramatically in the last two decades leading to increased use by pregnant women. Despite evidence for increasing marijuana use and high rates of co-use of tobacco (TOB) and marijuana (MJ) during pregnancy, the impact of prenatal exposure to each substance is typically studied in isolation. We investigated the influence of co-exposure to TOB and MJ on infant neurobehavioral development over the first postnatal month. Participants were 111 mother-infant pairs from a low-income, diverse sample (Mean age = 25 ± 5; 54% minorities). TOB and MJ use were assessed by Timeline Followback interview with biochemical confirmation. Three groups were identified: (a) prenatal MJ + TOB, (b) prenatal TOB only, (c) controls. Newborn neurobehavior was assessed at seven time points over the first postnatal month using the NICU Network Neurobehavioral Scale. MJ + TOB-exposed infants showed decreased ability to self-soothe (Self-regulation) and attend to stimuli (Attention), and increased need for examiner soothing (Handling) and low motor activity (Lethargy) versus unexposed infants. Despite low levels of MJ use in MJ + TOB co-users, co-exposure was associated with nearly double the impact on infant self-soothing and need for examiner soothing versus TOB-exposure alone. Effects of MJ + TOB co-exposure appeared more pronounced for daughters than for sons. Although results are preliminary, they highlight additional risk from dual exposure to MJ + TOB vs. TOB exposure alone, particularly for daughters. Results also highlight the critical importance of investigating prenatal exposures in concert and the need for intervention efforts to address MJ co-use in pregnant TOB users.

Orthopaedic surgery patients who use recreational marijuana have less pre-operative pain.

To determine the baseline clinical characteristics of recreational marijuana users undergoing outpatient orthopaedic surgery. We hypothesized that patients who report marijuana use would have worse pain, function, and general health status. Nine-hundred and thirty-seven patients undergoing outpatient orthopaedic surgery were asked to fill out patient-reported outcome (PRO) tools. These PROs included the Patient-Reported Outcomes Measurement Information Systems (PROMIS) computer adaptive tests and legacy PROs unique to each patients' surgical site. Forty patients (4.2%) reported marijuana use. Marijuana use was associated with younger age (33 vs. 43years, p < 0.001), having a history of fewer operations (1.8 vs. 3.2, p < 0.05), single marital status (68 vs. 38%, p < 0.01), and having a history of smoking cigarettes (63 vs. 31%, p < 0.0001). Marijuana use was found to be significantly associated with greater Marx lower extremity activity rating scale scores (8.5 points vs. 6.1 points, p < 0.05) and decreased pain intensity in the operative site (3.7 points vs. 5.0 points, p < 0.05). Multivariable analysis found that marijuana use was an independent factor associated with less pain intensity in the operative site (p < 0.05). Our studies support other national studies that report increased marijuana use among younger patients and those who smoke cigarettes. The results do not support our hypothesis, as marijuana use was associated with less pain and better lower extremity activity rating scale scores when compared to non-users. Further research is warranted to analyze the effects of marijuana use on orthopaedic surgery patients. Cross-sectional study.

High times: The effect of medical marijuana laws on student time use

Medical marijuana laws (MMLs) represent a major change of marijuana policy in the U.S. Previous research shows that these laws increase marijuana use among adults. In this paper, we estimate the effects of MMLs on secondary and post-secondary students’ time use using data from the American Time Use Survey. We apply a difference-in-differences research design and estimate flexible fixed effects models that condition on state fixed effects and state-specific time trends. We find no effect of MMLs on secondary students’ time use. However, we find that college students in MML states spend approximately 20% less time on education-related activities and 20% more time on leisure activities than their counterparts in non-MML states. These behavioral responses largely occur during weekends and summer when students have more spare time. Finally, the impacts of MMLs are heterogeneous and stronger among part-time college students, who are more likely to be first-generation college goers and to come from underrepresented racial and ethnic groups.

The Legalization of Medical/Recreational Marijuana: Implications for School Health Drug Education Programs.

More than half of US states have legalized medical marijuana. Several states have also legalized it for recreational use. In spite of states' actions, marijuana remains illegal under federal law. It remains to be seen, however, if the Trump administration will enforce federal law in states that have legalized marijuana. For now, it appears the move toward state legalization of marijuana will increase. Because of its legal status, research concerning the medical benefits of marijuana has been limited. We reviewed the literature pertaining to medical use and legalization of marijuana. Available research shows that marijuana can benefit some conditions. There are also concerns about harmful effects on both individual and public health and whether legalization will lead to increased marijuana use among youth. Each of these elements has implications for school-based drug education programs. Researchers have shown that the 10 states with the highest rate of past month marijuana use by youth all have legalized recreational and/or medical use of marijuana, whereas none of the 10 states with the lowest rate of past month marijuana use by youth, has legalized marijuana. In the debate over legalization schools can potentially serve as a community resource, providing accurate information concerning marijuana. Teachers and parents should continue to discourage young people from using marijuana (as well as alcohol, tobacco, and other drugs).

Substance use and use disorders and treatment receipt among adults in families receiving Temporary Assistance for Needy Families (TANF), 2003–2014

Background/purposeLegalization of marijuana for medical and/or recreational use in some U.S. states has increased attention to substance use and related problems. However, little attention has been paid to these phenomena among adults in families receiving Temporary Assistance for Needy Families (TANF) whose adverse life experiences may put them at elevated risk of substance use disorders (SUDs). MethodsData from the 2003–2014 National Survey on Drug Use and Health (NSDUH) were used to test trends in past-month binge drinking and past-year marijuana, other illicit drug, and any illicit drug use and to examine SUD prevalence and treatment correlates among adults in TANF families. ResultsWhile rates of binge drinking and any illicit drug use remained steady, marijuana use increased from 15.8% in 2003/2004 to 21.6% in 2013/2014, a 36.7% increase. Increased marijuana use was strongly related to changes in marijuana risk perception. Among adults in TANF families, 19.5% of men and 10.8% of women had a past-year SUD, but only one in five received treatment. Those aged 18–25, Black or Hispanic women, and those who had children at home when surveyed were less likely to have received treatment. DiscussionPreventive efforts to address substance use, especially marijuana use, among adults in TANF families are needed. Moreover, given greater odds of unmet SUD treatment need among these economically disadvantaged adults, particularly racial/ethnic minority women and those who are in emerging adulthood, uninsured, and have children at home, measures to provide more inclusive services such as integrated behavioral health care are needed.

A.04 High times? Prevalence and perceptions of marijuana use among patients with epilepsy

Background: Despite medical advances, almost a third of people with epilepsy have medically refractory epilepsy (MRE). With failure of pharmaceutical options, patients are turning to alternative treatment options. Marijuana use in epilepsy has received extensive attention. Two recent studies evaluated the opinions of marijuana use in individuals with epilepsy, but had discrepant marijuana use rates. Methods: The first 200 adult patients with a known diagnosis of epilepsy seen at Hamilton General Hospital after June 1, 2017 were invited to participate. Standardized paper questionnaires gathered information about demographics, epilepsy history, and marijuana use. Results: One hundred forty participants returned questionnaires; 29.5% were active marijuana users; 24.5% had consumed marijuana in the past. Increased seizure frequency was significantly associated with marijuana use. There was a non-significant trend towards increased marijuana use with males and MRE. Almost half the active marijuana users noted improvement in seizure frequency. No participants experienced worsening of epilepsy with marijuana use. Side effects were common (30%), most frequent being mood. Conclusions: Prevalence of marijuana use among people with epilepsy is higher in our study population compared to an Australian cohort, but similar to Canadian studies. Marijuana use was significantly associated with increased seizure frequency. The majority of patients perceived benefit with regard to seizure control.

Planting the seed for marijuana use: Changes in exposure to medical marijuana advertising and subsequent adolescent marijuana use, cognitions, and consequences over seven years

BackgroundMarijuana use during adolescence is associated with neurocognitive deficits and poorer functioning across several domains. It is likely that more states will pass both medical and recreational marijuana legalization laws in the coming elections; therefore, we must begin to look more closely at the longitudinal effects of medical marijuana (MM) advertising on marijuana use among adolescents so that we can better understand effects that this advertising may have on their subsequent marijuana use and related outcomes. MethodsWe followed two cohorts of 7th and 8th graders (mean age 13) recruited from school districts in Southern California from 2010 until 2017 (mean age 19) to examine effects of MM advertising on adolescents’ marijuana use, cognitions, and consequences over seven years. Latent growth models examined trajectories of self-reported exposure to medical marijuana ads in the past three months and trajectories of use, cognitions, and consequences. ResultsHigher average exposure to MM advertising was associated with higher average use, intentions to use, positive expectancies, and negative consequences. Similarly, higher rates of change in MM advertising exposure were associated with higher rates of change in use, intentions, expectancies, and consequences over seven years. ConclusionsResults suggest that exposure to MM advertising may not only play a significant role in shaping attitudes about marijuana, but may also contribute to increased marijuana use and related negative consequences throughout adolescence. This highlights the importance of considering regulations for marijuana advertising, similar to regulations in place for the promotion of tobacco and alcohol in the U.S.

A longitudinal assessment of change in marijuana use with other substance use problems

ABSTRACTBackground: Despite increasing marijuana use rates over the past decade, the longitudinal association between marijuana use and other substance use problems among adults is unclear. Objectives: To examine associations of self-reported changes in marijuana use and marijuana use frequency with self-reported other substance use problems over a 12-month period. Methods: Two waves (W1 and W2) of the Population Assessment of Tobacco and Health Study provided data. The study sample (N = 26,204, female = 13,261; male = 12,943, aged 18+) included W1-W2 never marijuana users, W1-W2 ex-users (used prior to 12 months of W1), and those who either quit, initiated, resumed, or continued marijuana use between W1 and W2. We used multinomial and binary logistic regression analyses. Results: The past-year marijuana use rate was 12.4% at W2. A quarter of W1 users quit using marijuana in the 12 months preceding their W2 interview, and one-third of all the W2 users were new/resumed users since W1. Compared to W1-W2 ex-users, W2 quitters were more likely to report alcohol use problems and tobacco addiction at W2. Compared to quitters, continued users were more likely to report alcohol use problems (RRR = 1.62, 95% CI = 1.27–2.07) and tobacco addiction (RRR = 1.37, 95% CI = 1.11–1.69). New users (RRR = 2.05, 95% CI = 1.12–3.74), resumed users (RRR = 2.69, 95% CI = 1.55–4.70), and continued users (RRR = 3.40, 95% CI = 2.08–5.55) reported more drug use problems. Compared to less frequent marijuana users, frequent users had greater odds of reporting alcohol use problems (RRR = 1.44, 95% CI = 1.21–1.72) and drug use problems (OR = 1.63, 95% CI = 1.19–2.23). Conclusions: Given increased prevalence of marijuana use, polysubstance use problems among marijuana users should be assessed.

Neurodevelopmental outcomes and prenatal exposure to marijuana.

BACKGROUND: Increased use of marijuana in pregnancy (3.9% in 2014 compared with 2.4% in 2002 in a recent self-reported survey) is a significant problem and poses potential health risks for the developing fetus. Studies have shown that the fetal endocannabinoid receptor system may be vulnerable to intrauterine exposure to THC (Tetrahydrocannabinol) and may produce long-term consequences on behavior and psychopathology in children. There are, however, limited studies evaluating the impact of prenatal marijuana use …

The Interplay Between Marijuana-Specific Risk Factors and Marijuana Use Over the Course of Adolescence.

Permissive attitudes and norms about marijuana use and perceptions of low harm from use are considered risk factors for adolescent marijuana use. However, the relationship between risk and use may be reciprocal and vary across development and socializing domains. We examined the bidirectional relationships between marijuana-specific risk factors in individual, parent, peer, and community domains and adolescent marijuana use. Longitudinal data came from a sample of 2002 adolescents in 12 communities. Controlling for sociodemographic covariates and communities in which the individuals resided, autoregressive cross-lagged models examined predictive associations between the risk factors and marijuana use. After accounting for concurrent relationships between risk and use and stability in behavior over time, early adolescence and the transition to high school were particularly salient developmental time points. Specifically, higher risk in all four domains in grades 7 and 9 predicted greater use 1year later. Moreover, youth's perception of lax community enforcement of laws regarding adolescent use at all time points predicted increases in marijuana use at the subsequent assessment, and perceived low harm from use was a risk factor that prospectively predicted more marijuana use at most of the time points. Finally, greater frequency of marijuana use predicted higher levels of risk factors at the next time point in most socializing domains throughout adolescence. Prevention programs should take into account developmental transitions, especially in early adolescence and during the transition to high school. They also should focus on the reciprocal relationships between use and risk across multiple socializing domains.

Marijuana use among US tobacco users: Findings from wave 1 of the population assessment of tobacco health (PATH) study

BackgroundWith an increase in marijuana use among adults in the United States (US), understanding the potential impact of marijuana use on tobacco use and associated behavioral and health consequences, including respiratory conditions, is necessary. MethodSurvey responses from Wave 1 of the nationally representative Population Assessment of Tobacco and Health (PATH) Study were used to assess tobacco use and marijuana use among non-current tobacco users (n = 17,952) and current established tobacco-users classified as: cigarette only users (n = 8689), e-cigarette only users (n = 437), cigar only (traditional, cigarillo, or filtered) users (n = 706), hookah only users (n = 461), smokeless tobacco only users (n = 971), cigarette + e-cigarette users (n = 709), and users of multiple tobacco products (n = 2314). ResultsWhen compared to non-current tobacco users, each tobacco user group except smokeless only users had higher odds (odds ratios ranging from 3.86–8.07) of reporting current marijuana use. Among current tobacco users, higher levels of tobacco dependence did not explain the relationship between tobacco use and marijuana use. Additionally, concurrent marijuana use was associated with lower odds of attempts to quit tobacco (OR = 0.86, 95% CI = 0.79, 0.94, p < 0.001) and a higher probability (OR = 1.35, 95CI = 1.21, 1.51, p < 0.01) of reporting a history of respiratory disease. ConclusionsThe association between concurrent use of tobacco and marijuana and higher tobacco dependence and lower rates of quit attempts suggests the potential for sustained tobacco use and deleterious health effects. Further, marijuana use may represent an additive risk for respiratory harm among concurrent users of tobacco and marijuana.