Adult Marijuana Research Articles

Patterns and correlates of the co-use of marijuana with any tobacco and individual tobacco products in young adults from Wave 2 of the PATH Study

BackgroundPast-month marijuana use has increased significantly among US young adults (aged 18–24) and marijuana use often overlaps with tobacco use. This study investigated the relative prevalence and correlates of individual tobacco product use among young adult marijuana and tobacco users to determine if unique typologies could be identified. MethodData were from young adults (18–24) in Wave 2 of the Population Assessment of Tobacco and Health (PATH) Study. Analyses examined the prevalence of different patterns of past 30-day marijuana and tobacco use and co-use. Weighted adjusted models were used to examine correlates of different marijuana and individual tobacco co-use profiles (compared to no-use of either product). ResultsPrevalence estimates showed that 30.9% of young adults report past month tobacco-only use, 21.3% report past-month co-use of marijuana and at least one tobacco product, and 4.5% report past 30-day marijuana-only use. Correlates of co-use differed by tobacco product. Using 3+ tobacco products and frequency of past 30-day alcohol use were robustly and consistently associated with each marijuana and individual tobacco co-use profile and any co-use of marijuana with tobacco. ConclusionsAmong US young adults between 2014 and 2015, co-use of marijuana and tobacco was common, and there was heterogeneity in correlates associated with use of different tobacco products among those who used marijuana. Different correlates suggest different targets for marijuana and tobacco prevention and intervention in this age group.

Greater risk for frequent marijuana use and problems among young adult marijuana users with a medical marijuana card

BackgroundThis study compared young adults with and without a medical marijuana (MM) recommendation from a provider (“MM card”) on their developmental trajectories of frequent marijuana use and marijuana-related problems in young adulthood. MethodsThe analytic sample consists of young adult past month marijuana users (N = 671) who were part of a larger, diverse, and predominantly California cohort. Analyses are based on data from seven surveys completed from ages 13–19. ResultsAt age 19, 28% of participants reported having an MM card to legally purchase marijuana from an MM dispensary. A multiple group latent growth model indicated that young adults who had an MM card showed steeper increases in frequent marijuana use (i.e., 20–30 days of use in the past month) from ages 13–19 compared to young adults who did not have an MM card. Logistic regression models that matched MM cardholders and non-MM cardholders on individual sociodemographic characteristics found that MM cardholders were more likely to report marijuana negative consequences, selling marijuana/hashish, and driving under the influence of marijuana in the past year. In addition, MM cardholders were more likely to have tried cutting down or quitting in the past 3-months. ConclusionsAmong young adult marijuana users, those with an MM card had a higher risk profile for marijuana use and related problems compared to those without an MM card. Given expanding state legalization of MM, this issue warrants further attention.

Simultaneous Alcohol and Marijuana Use Among Young Adult Drinkers: Age-Specific Changes in Prevalence from 1977 to 2016.

The overall prevalence of U.S. young adult alcohol use has decreased, but little is known about historical change in related behaviors such as simultaneous alcohol and marijuana (SAM) use that may increase alcohol-related risks and societal costs. The purpose of this paper was to examine historical change in SAM use prevalence among U.S. young adult alcohol users from 1977 to 2016, and consider the extent to which observed historical change in SAM use among alcohol users reflects co-occurring change in marijuana use during these years. Data on past 12-month alcohol, marijuana, and SAM use at up to 6 modal ages (19/20, 21/22, 23/24, 25/26, 27/28, and 29/30) were collected from 11,789 individuals (45.0% men) participating in the Monitoring the Future panel study. Annual prevalence estimates within modal age group were obtained; historical SAM use trends among alcohol and marijuana users were estimated. From 2014 to 2016, SAM use was reported by approximately 30% of alcohol users aged 19/20 and 21/22, and 20 to 25% of alcohol users aged 23/24 through 29/30. Since the mid-1990s, age-specific historical trends in SAM use prevalence among alcohol users followed 1 of 4 patterns: significant increase followed by oscillating increases/decreases (at modal age 19/20), consistent and significant increases (at modal ages 21/22, 23/24, and 25/26), stability followed by increase (at modal ages 27/28), or stability (at modal ages 29/30). In contrast, SAM use trends among marijuana users primarily reflected stability, with some evidence of a decrease across time at modal ages 19/20 and 23/24. Historical change in SAM prevalence among alcohol users was strongly and positively correlated with changes in overall marijuana use prevalence. A growing proportion of early and mid-young adult alcohol users reported SAM use, with the highest risk among those in the early years of young adulthood. Young adult SAM use may continue to increase in proportion to the degree that young adult marijuana use continues to increase.

Relative influence of perceived peer and family substance use on adolescent alcohol, cigarette, and marijuana use across middle and high school

PurposeSubstance use by peers and family may affect adolescent substance use, yet the relative influence may shift during adolescence as youth differentiate themselves from family and more closely affiliate with peers. This study examined trends in concordance of adolescent cigarette, alcohol and marijuana use and corresponding perceived use by friends and family members during middle and high school. MethodsData are from a longitudinal cohort of 12,038 youth who completed up to five surveys during grades 6–12. At each wave, adolescents reported past month use of cigarettes, alcohol and marijuana, as well as perceived use by their best friend, older sibling and most important adult figure. For each substance, we used time-varying effect models to estimate how associations between adolescent use and perceived use varied across grade. ResultsFor all substances, concordance with best friend use was positive and stronger than concordance with older sibling or adult use at all grades. Concordance with both best friend and older sibling use of all substances was pronounced in 6th grade. Concordance peaked again during mid-high school for smoking (best friend, older sibling) and marijuana (best friend). Concordance with adult marijuana use peaked in middle school, yet associations with adult alcohol and cigarette use were relatively stable. ConclusionsSubstance use prevention efforts that seek to counter peer normative pressures should begin prior to middle school and span high school. Such efforts should address the role of peer and family environments, as both were found to be relevant during middle and high school.

Adolescent Marijuana Use, Marijuana-Related Perceptions, and Use of Other Substances Before and After Initiation of Retail Marijuana Sales in Colorado (2013–2015)

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

Consideration of future consequences as a moderator of the willingness-behavior relationship for young adult marijuana use and consequences

The Prototype Willingness Model is a dual-processing (i.e., intentional and socially reactive) health-risk behavior model. The socially reactive path includes behavioral willingness, descriptive normative perceptions, and favorable images of individuals who engage in health-risk behavior (prototype favorability) as important predictors of health behaviors. Individual differences (such as consideration of future consequences) may potentiate the effects of behavioral willingness on health-risk outcomes, such as marijuana use. Given limited research investigating marijuana use and the Prototype Willingness Model, the goals of the current study were: 1) examine consideration of future consequences and Prototype Willingness Model social reaction pathway variables in relation to behavioral willingness to use marijuana longitudinally; and 2) determine if consideration of future consequences moderated the behavioral willingness-marijuana use relation prospectively. Young adults (N = 769) from a larger longitudinal study completed baseline and 3 follow-up assessments (Months 3, 4, 5). Behavioral willingness was positively related to a higher likelihood of use, more days having used marijuana, and more consequences prospectively, over and above baseline use. Consideration of future consequences moderated the association between behavioral willingness and hours high in a typical week. These findings support the willingness-behavior association of the Prototype Willingness Model and preliminarily demonstrate consideration of future consequences' differential impact on behavioral willingness-future marijuana use relation. Intervention and prevention implications are discussed.

The Effect of Medical Marijuana Laws on Marijuana-Related Attitude and Perception Among US Adolescents and Young Adults.

Marijuana liberalization policies are gaining momentum in the USA, coupled with limited federal interference and growing dispensary industry. This evolving regulatory landscape underscores the importance of understanding the attitudinal/perceptual pathways from marijuana policy to marijuana use behavior, especially for adolescents and young adults. Our study uses the restricted-access National Survey on Drug Use and Health (NSDUH) 2004-2012 data and a difference-in-differences design to compare the pre-policy, post-policy changes in marijuana-related attitude/perception between adolescents and young adults from ten states that implemented medical marijuana laws during the study period and those from the remaining states. We examined four attitudinal/perception pathways that may play a role in adolescent and young adult marijuana use behavior, including (1) perceived availability of marijuana, (2) perceived acceptance of marijuana use, (3) perceived wrongfulness of recreational marijuana use, and (4) perceived harmfulness of marijuana use. We found that state implementation of medical marijuana laws between 2004 and 2012 was associated with a 4.72% point increase (95% CI 0.15, 9.28) in the probability that young adults perceived no/low health risk related to marijuana use. Medical marijuana law implementation is also associated with a 0.37% point decrease (95% CI - 0.72, - 0.03) in the probability that adolescents perceived parental acceptance of marijuana use. As more states permit medical marijuana use, marijuana-related attitude/perception need to be closely monitored, especially perceived harmfulness. The physical and psychological effects of marijuana use should be carefully investigated and clearly conveyed to the public.

Marijuana Use among Young Adults: Who Quits and Why?

In this study, we examined: (1) differences among never, current, and former young adult marijuana users; and (2) reasons for use and cessation. We conducted interviews with 57 young adults (including 46 marijuana users) enrolled in a longitudinal study of 3418 young adults and a survey in this cohort (N = 2866). Participants reporting former but not current use on the survey (N = 607) completed the Reasons for Marijuana Cessation section. Interview data indicated reasons for initiating (or not initiating) use, continued use, and quitting. The Reasons for Marijuana Cessation scale included 2 factors: (1) Instrumentality and 2) Social/Legal reasons. These findings might inform theoretical frameworks upon which marijuana cessation occurs and direct future intervention studies.

The Self-Report Habit Index: Assessing habitual marijuana, alcohol, e-cigarette, and cigarette use

BackgroundSubstance use is partially driven by habitual processes that occur automatically in response to environmental cues and may be central to users’ identities. This study was designed to validate the Self-Report Habit Index (SRHI) for assessing habitual marijuana, alcohol, cigarette, and e-cigarette use. MethodsWe examined the SRHI’s psychometrics in separate samples of adult marijuana (Ns = 189;170), alcohol (Ns = 100;133), cigarette (Ns = 58;371), and e-cigarette (N = 239) users. ResultsA 6-item, single-factor solution evidenced good fit across substances (CFI marijuana/alcohol/cigarettes/e-cigarettes = 0.996/0.997/0.996/0.994, RMSEA = 0.046/0.047/0.067/0.068, SRMR = 0.017/0.017/0.010/0.015) and internal consistency (α = 0.88/0.94/0.95/0.91). The SRHI was scalar invariant for sex and race. However, independent-samples t-tests indicated only that women endorsed stronger habitual e-cigarette use and that men endorsed stronger habitual marijuana use. The SRHI also was scalar invariant by product type in dual-users (cigarettes/e-cigarettes[N = 371]; alcohol/cigarettes [n = 58]), although differences in habit strength only were observed for cigarettes versus e-cigarettes, with dual-users reporting stronger habitual cigarette use. Finally, the SRHI predicted frequency of marijuana, alcohol, cigarette, and e-cigarette use (np2 [marijuana/alcohol/cigarettes/e-cigarettes] = 0.37/0.48/0.31/0.17) and quantity of alcohol and cigarette use (np2 = 0.43/0.33). ConclusionsThe SRHI is a psychometrically sound measure of adults’ habitual substance use. The SRHI detected mean differences by sex and substance type and predicted the frequency of using each substance. Future research should determine if the SRHI is appropriate for use with other substances or age groups (e.g., adolescents), how it relates to task-based, behavioral measures of habit strength, and the degree to which habit predicts the development or maintenance of addiction.

Marijuana use predicts onset of current little cigar use in a national sample of US young adults

BackgroundThis study examined whether young adult marijuana use increases risk of subsequent large cigar (LC) and little cigar/cigarillo (LCC) use among naïve users. MethodsData were from 8 waves of the Truth Initiative Young Adult Cohort, a national sample of US young adults aged 18–34 assessed every 6 months. Discrete-time survival analyses examined whether baseline ever marijuana use among never cigar users predicted onset of past 30-day LC and LCC use and whether baseline ever LC and LCC use among never marijuana users predicted onset of past 30-day marijuana use. Models adjusted for demographics, past 30-day alcohol use, past 30-day tobacco product use, and menthol tobacco use. ResultsIn adjusted models, baseline ever marijuana use predicted onset of past 30-day LCC but not LC use. Cumulative risk ratios showed that 23% of ever marijuana users at baseline reported past 30-day use of LCCs by the end of wave 8 compared to just 3% of baseline never marijuana users. Race and past 30-day use of specific tobacco products also predicted onset of past 30-day LC and LCC use. Past 30-day use of alcohol uniquely predicted onset of past 30-day LCC use but not LC use. Baseline ever LC and LCC use did not predict onset of past 30-day marijuana use in models that adjusted for demographics, alcohol, and specific tobacco product use. ConclusionsEver marijuana use among US young adults may be an important predictor of onset of regular LCC use. Findings suggest different pathways linking marijuana to different cigar sub-types.

Novel approaches for teen alcohol, young adult marijuana use

Alcoholism & Drug Abuse WeeklyVolume 29, Issue 45 p. 5-6 Articles Novel approaches for teen alcohol, young adult marijuana use Alison Knopf, Alison KnopfSearch for more papers by this author Alison Knopf, Alison KnopfSearch for more papers by this author First published: 19 November 2017 https://doi.org/10.1002/adaw.31782Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume29, Issue4520 November 2017Pages 5-6 RelatedInformation

2.2 Clinical Issues Arising in the Context of Adult Recreational Marijuana Legalization

2.2 Clinical Issues Arising in the Context of Adult Recreational Marijuana Legalization

Depression and marijuana use disorder symptoms among current marijuana users

BackgroundDepression is one of the most consistent risk factors implicated in both the course of escalating substance use behaviors and in the development of substance dependence symptoms, including those associated with marijuana use. In the present study, we evaluate if depression is associated with marijuana use disorder symptoms across the continuum of marijuana use frequency. MethodsData were drawn from six annual surveys of the National Survey of Drug Use and Health to include adults who reported using marijuana at least once in the past 30days (N=28,557). ResultsAfter statistical control for sociodemographic characteristics and substance use behaviors including marijuana use, alcohol use, smoking, and use of illicit substances other than marijuana, depression was positively and significantly associated with each of the marijuana use disorder symptoms as well as the symptom total score. Adult marijuana users with depression were consistently more likely to experience marijuana use disorder symptoms and a larger number of symptoms, with the magnitude and direction of the relationship generally consistent across all levels of marijuana use frequency from 1day used in the past month to daily marijuana use. ConclusionsDepression is a consistent risk factor for marijuana use disorder symptoms over and above exposure to marijuana suggesting that depressed individuals may represent an important subgroup in need of targeted substance use intervention.

Marijuana Use and Driving Under the Influence among Young Adults: A Socioecological Perspective on Risk Factors

ABSTRACTBackground: Given increases in marijuana use and driving under the influence (DUI), it is critical to identify those at risk in order to inform intervention efforts. Objectives: We used a socioecological framework to examine correlates of level of marijuana use and DUI in the past month among young adult marijuana users. Methods: We recruited 1567 participants aged 18–34 years via Facebook ads targeting tobacco and marijuana users in August 2014 to complete an online survey assessing marijuana use and DUI, as well as related multilevel factors. Analyses focused on 649 participants reporting past 30-day marijuana use. Results: The sample was an average age of 24.48 (SD = 5.10), 43.9% female, and 76.4% White and used marijuana an average of 17.86 (SD = 11.29) days in the past month. Notably, 48.4% reported driving after marijuana use at least once in the past month, and 74.0% were passengers. Multivariable regression indicated that greater use was associated with: being older; being male; greater symptoms of dependence; residing in a state with recreational marijuana legalized; having a medical marijuana card; having parents and more friends who use; higher coping motives; lower perceived harm to health; and less concern about driving after marijuana use (adjusted R-squared = 0.294). Correlates of driving after using marijuana in the past month included: being younger; more frequent use; having more friends who use; higher enhancement motives; and less concern about driving after using (Nagelkerke R-squared = 0.442). Conclusions/Importance: Interventions and campaigns should address social norms and risk perceptions regarding marijuana use, particularly as it relates to DUI.

Loose regulation of medical marijuana programs associated with higher rates of adult marijuana use but not cannabis use disorder.

Most US states have passed medical marijuana laws (MMLs), with great variation in program regulation impacting enrollment rates. We aimed to compare changes in rates of marijuana use, heavy use and cannabis use disorder across age groups while accounting for whether states enacted medicalized (highly regulated) or non-medical mml programs. Difference-in-differences estimates with time-varying state-level MML coded by program type (medicalized versus non-medical). Multi-level linear regression models adjusted for state-level random effects and covariates as well as historical trends in use. Nation-wide cross-sectional survey data from the US National Survey of Drug Use and Health (NSDUH) restricted use data portal aggregated at the state level. Participants comprised 2004-13 NSDUH respondents (n~67 500/year); age groups 12-17, 18-25 and 26+ years. States had implemented eight medicalized and 15 non-medical MML programs. Primary outcome measures included (1) active (past-month) marijuana use; (2) heavy use (>300days/year); and (3) cannabis use disorder diagnosis, based on DSM-IV criteria. Covariates included program type, age group and state-level characteristics throughout the study period. Adults 26+ years of age living in states with non-medical MML programs increased past-month marijuana use 1.46% (from 4.13 to 6.59%, P=0.01), skewing towards greater heavy marijuana by 2.36% (from 14.94 to 17.30, P=0.09) after MMLs were enacted. However, no associated increase in the prevalence of cannabis use disorder was found during the study period. Our findings do not show increases in prevalence of marijuana use among adults in states with medicalized MML programs. Additionally, there were no increases in adolescent or young adult marijuana outcomes following MML passage, irrespective of program type. Non-medical marijuana laws enacted in US states are associated with increased marijuana use, but only among adults aged 26+ years. Researchers and policymakers should consider program regulation and subgroup characteristics (i.e. demographics) when assessing for population level outcomes. Researchers and policymakers should consider program regulation and subgroup characteristics (i.e. demographics) when assessing for population level outcomes.

Predictors of Adult Marijuana Use Among Parents and Nonparents.

The current study examined predictors of marijuana use among adults, including subsamples of adults who are actively parenting (i.e., have regular face-to-face contact with a child) and those who have no children. Participants were a community sample of 808 adults and two subsamples drawn from the full group: 383 adults who were actively parenting and 135 who had no children. Multilevel models examined predictors of marijuana use in these three groups from ages 27 to 39. Becoming a parent was associated with a decrease in marijuana use. Regular marijuana use in young adulthood (ages 21-24), partner marijuana use, and pro-marijuana attitudes increased the likelihood of past-year marijuana use among all participants. Being a primary caregiver (among parents) was associated with less marijuana use. Overall, predictors of marijuana use were similar for all adults, regardless of parenting status. Study results suggest that the onset of parenthood alone may be insufficient to reduce adult marijuana use. Instead, preventive intervention targets may include changing adult pro-marijuana attitudes and addressing marijuana use behaviors of live-in partners. Lastly, universal approaches targeting parents and nonparents may be effective for general adult samples.

Prevalence, correlates, and trends in tobacco use and cessation among current, former, and never adult marijuana users with a history of tobacco use, 2005–2014

BackgroundApproximately 70% of current (past 30-day) adult marijuana users are current tobacco users, which may complicate tobacco cessation. We assessed prevalence and trends in tobacco cessation among adult ever tobacco users, by marijuana use status. MethodsData came from the National Survey on Drug Use and Health, a cross-sectional, nationally representative, household survey of U.S. civilians. Analyses included current, former, and never marijuana users aged≥18 reporting ever tobacco use (cigarette, cigar, chew/snuff). We computed weighted estimates (2013–2014) of current tobacco use, recent tobacco cessation (quit 30days to 12months), and sustained tobacco cessation (quit>12months) and adjusted trends in tobacco use and cessation (2005–2014) by marijuana use status. We also assessed the association between marijuana and tobacco use status. ResultsIn 2013–2014, among current adult marijuana users reporting ever tobacco use, 69.1% were current tobacco users (vs. 38.5% of former marijuana users, p<0.0001, and 28.2% of never marijuana users, p<0.0001); 9.1% reported recent tobacco cessation (vs. 8.4% of former marijuana users, p<0.01, and 6.3% of never marijuana users, p<0.001), and 21.8% reported sustained tobacco cessation (vs. 53.1% of former marijuana users, p<0.01, and 65.5% of never marijuana users, p<0.0001). Between 2005 and 2014, current tobacco use declined and sustained tobacco cessation increased among all marijuana use groups. ConclusionsCurrent marijuana users who ever used tobacco had double the prevalence (vs. never-marijuana users) of current tobacco use, and significantly lower sustained abstinence. Interventions addressing tobacco cessation in the context of use of marijuana and other substances may be warranted.

Marijuana advertising exposure among current marijuana users in the U.S.

BackgroundLittle is known about marijuana advertising exposure among users in the U.S. We examined the prevalence of advertising exposure among young adult marijuana users through traditional and new media, and identified characteristics associated with seeking advertisements. MethodsWe conducted a cross-sectional survey of 18–34 year-old past-month marijuana users in the U.S. using a pre-existing online panel (N=742). The survey queried about passively viewing and actively seeking marijuana advertisements in the past month, sources of advertisements, and marijuana use characteristics. ResultsOver half of participants were exposed to marijuana advertising in the past month (28% passively observed advertisements, 26% actively sought advertisements). Common sources for observing advertisements were digital media (i.e., social media, online, text/emails; 77%). Similarly, those actively seeking advertisements often used Internet search engines (65%) and social media (53%). Seeking advertisements was more common among those who used medically (41% medical only, 36% medical and recreational) than recreational users (18%), who used concentrates or edibles (44% and 43%) compared to those who did not (20% and 19%), and who used multiple times per day (33%) compared to those who did not (19%) (all p<0.01). ConclusionsExposure to marijuana advertising among users is common, especially via digital media, and is associated with medical use, heavier use, and use of novel products with higher THC concentrations (i.e., concentrates) or longer intoxication duration (i.e., edibles). As the U.S. marijuana policy landscape changes, it will be important to examine potential causal associations between advertising exposure and continuation or frequency/quantity of use.

Lessons learned after three years of legalized, recreational marijuana: The Colorado experience.

In November 2012 Colorado voters approved legalized recreational marijuana. On January 1, 2014 Colorado became the first state to allow legal sales of non-medical marijuana for adults over the age of 21. Since that time, the state has been monitoring potential impacts on population health. In this paper we present lessons learned in the first three years following legal sales of recreational marijuana. These lessons pertain to health behaviors and health outcomes, as well as to health policy issues. Our intent is to share these lessons with other states as they face the prospect of recreational marijuana legalization.

Illicit drug use among young adult marijuana users in los angeles: Implications for medical use

Illicit drug use among young adult marijuana users in los angeles: Implications for medical use