Perceived friends' use as a risk factor for marijuana use across young adulthood

Social Norms for Cannabis Use After Nonmedical Legalization in Canada

INTRODUCTION

Social norms play an important role in cannabis use; however, there is little evidence on how social norms change in jurisdictions that legalize cannabis. This study examined trends in social norms before and after legalization of nonmedical cannabis in Canada in 2018.

METHODS

Data are from the International Cannabis Policy Study, a series of cross-sectional surveys conducted annually with Canadian respondents aged 16-65 years. Analyses were conducted in 2023 and included data from 58,045 respondents across 4 waves: the year immediately before legalization (2018) and 3 post-legalization waves (2019-2021). Regression models examined trends in injunctive norms (perceived approval of cannabis) and comfort in using cannabis in six different social contexts, adjusting for cannabis use frequency, medical authorization, and sociodemographic covariates.

RESULTS

Perceived social approval of cannabis use and comfort using cannabis in different social contexts was highest among males, frequent cannabis consumers, and those who reported medical authorization (p<0.05 in all cases). No changes in perceived approval were observed across years, except a temporary decrease in 2020 versus 2018 (OR=0.87, 95% CI=0.80, 0.95). Modest increases in comfort of using cannabis in 6 different social contexts were observed in 2019 (ß=0.10, p=0.001), 2020 (ß=0.10, p=0.001), and 2021 (ß=0.12, p<0.001) versus in 2018.

CONCLUSIONS

Social norms have remained relatively stable after nonmedical legalization in Canada, with only modest increases in comfort of using cannabis in different social settings. The findings may reflect widespread cannabis use in Canada prior to nonmedical legalization in 2018 as well as comprehensive restrictions on promotion and advertising.

Marijuana use behaviors on Texas college campuses

There is limited contemporary research examining marijuana use behaviors that occur on college campuses.

PURPOSE

This study aimed to determine: (1) What is the prevalence of marijuana use on college campuses, (2) where are students commonly using marijuana on college campuses, (3) what are the sociodemographic characteristics of students most likely to use marijuana on a college campus, and (4) how do these findings vary between modes of marijuana use (i.e., vaped versus another mode)?

METHODS

Participants were 14,005 college students (aged 18-25) enrolled in 19 Texas colleges during spring 2022 (Mean age = 20.16; 65.81% female; 30.85% non-Hispanic white, 42.08% Hispanic/Latino, 27.07% another race/ethnicity; 75.81% heterosexual).

RESULTS

Nearly 40% of students ever used marijuana and of these students, over 26% ever used marijuana on their college campus. Although the most common mode for marijuana use was smoking, the majority of students that used marijuana on a college campus reported vaping marijuana (64.89%). Students that ever vaped marijuana on campus were 2.35 times more likely than those that used marijuana via other modes to use marijuana in a public location on campus (i.e., not in a dormitory).

CONCLUSIONS

Findings indicate that marijuana use on college campuses is common and suggest that the ability to vape marijuana may increase marijuana use on college campuses, including in public locations such as classrooms and libraries. College campuses may consider increasing anti-marijuana enforcement efforts, especially those aimed at decreasing electronic vaping device use in general, in order to prevent and decrease marijuana use.

Risk Factors for Adolescent Cannabis Use in a State With Legal Recreational Cannabis: The Role of Parents, Siblings, and Friends

PURPOSE

Cannabis use during adolescence can have harmful consequences, including poor educational outcomes, neurocognitive defects, and an increased risk of addiction to other drugs, such as tobacco, alcohol, and opioids. Perceived family and social network cannabis use is a risk factor for use among adolescents. It is not currently known whether there is an association between perceived family/social network cannabis use and adolescent cannabis use in the context of legalization. The purpose of this study was to examine associations between adolescent perceptions of parent, sibling, and best friend medical and/or recreational cannabis use and adolescents' own use and whether the association changed pre-legalization and post-legalization in Massachusetts.

METHODS

We analyzed responses from surveys administered to students at 2 high schools in Massachusetts before legalization in 2016 (wave 1) and after legalization but before the start of regulated retail cannabis sales in 2018 (wave 2). We used χ2 tests and multiple logistic regression to examine associations between adolescent perception of parent, sibling, and best friend use and adolescent past 30-day cannabis use before and after legalization.

FINDINGS

In this sample, no statistically significant differences were found in the prevalence of past 30-day cannabis use before and after legalization among adolescents. There was an increase in the proportion of adolescents who reported any perceived parent cannabis use from before to after legalization (18% before legalization to 24% after legalization; P = 0.018). Perceived parent, sibling, and best friend medical and recreational cannabis use were all associated with an increased odds of adolescent use, with the highest increase in odds found for perceived best friend use (adjusted odds ratio, 17.2; 95% CI, 12.4-24.0).

IMPLICATIONS

Adolescent perceptions of their parents as cannabis users increased after legalization, even before state-regulated retails sales began. Parent, sibling, and best friend cannabis use is each independently associated with increased odds of adolescent's own use. These findings from 1 Massachusetts district should be explored in larger and more representative populations and motivate additional attention to interventions that consider family and friend influences when seeking to address adolescent cannabis use.

Individual and COVID-19-Specific Indicators of Compliance with Mask Use and Social Distancing: The Importance of Norms, Perceived Effectiveness, and State Response

COVID-19 is a global pandemic that has resulted in widespread negative outcomes. Face masks and social distancing have been used to minimize its spread. Understanding who will engage in protective behaviors is crucial for continued response to the pandemic. We aimed to evaluate factors that are indicative of mask use and social distancing among current and former college students prior to vaccine access. Participants (N = 490; 67% female; 60% White) were current and former U.S. undergraduate college students. Perceived effectiveness and descriptive norms regarding COVID-19 safety measures, COVID-19-related news watching and seeking, state response timing to stay-at-home mandates, impulsivity-like traits, affect (mood), and demographic variables were assessed. Results found that greater perceived effectiveness indicated increased personal compliance within and across behaviors. Greater norms related to compliance within behaviors (e.g., indoor norms related to indoor compliance). Increased perceived stress, anxiety, and negative affect indicated greater compliance. More positive affect was associated with less compliance. Being non-White, compared to White (p < 0.001), and female, compared to male (p < 0.001), were associated with greater compliance. Overall, early implementation of stay-at-home orders, exposure to COVID-19-related news, and increased perceived effectiveness are crucial for health safety behavior compliance. Findings are important for informing response to health crises, including COVID-19.

Associations between young adult marijuana outcomes and availability of medical marijuana dispensaries and storefront signage

AIMS

We investigated associations between the density of medical marijuana dispensaries (MMDs) around young adults' homes and marijuana use outcomes.

DESIGN

Secondary data analysis.

SETTING

Los Angeles County, CA, USA.

PARTICIPANTS

A total of 1887 participants aged 18-22 years, surveyed online in 2016-17.

MEASUREMENTS

Outcomes were past-month marijuana use (number of days used, number of times each day), positive expectancies and perceived peer use. Density was measured as the total number of MMDs and number of MMDs with storefront signage indicative of marijuana sales, within 4 miles of respondents' homes.

FINDINGS

Eighty-four per cent of respondents had 10 or more MMDs within 4 miles of their homes. Multiple linear regression analyses that adjusted for individual-level socio-demographic characteristics and neighborhood socio-economic status indicated that living near a higher number of MMDs was associated with greater number of days used in the past month [β = 0.025; 95% confidence interval (CI) = 0.001, 0.049; P = 0.04] and higher positive marijuana expectancies (β = 0.003; 95% CI = 0.001, 0.007; P = 0.04). Living near more MMDs with storefront signage had a four- to six-fold larger effect on number of times used per day and positive expectancies, respectively, compared with associations with the total MMD count. Adjusting for medical marijuana card ownership attenuated the association with number of days used in the past month and positive expectancies, and an unexpected association emerged between higher MMD density and fewer number of times used each day (β = -0.005; 95% CI = -0.009, -0.001; P = 0.03).

CONCLUSIONS

For young adults in Los Angeles County, living near more medical marijuana dispensaries (MMDs) is positively associated with more frequent use of marijuana within the past month and greater expectations of marijuana's positive benefits. MMDs with signage show stronger associations with number of times used each day and positive expectancies.

The accuracy of young adult cannabis users' perceptions of friends' cannabis and alcohol use

OBJECTIVE

Understanding the complex influence of peers on young adult substance use is an important component of intervention research and is challenging methodologically. The false consensus theory suggests that individuals falsely attribute their own substance use behaviors onto others, producing biased data.

METHODS

We tested this theory with 39 young adults who had a cannabis use disorder and a mean age of 20. Participants (egos) recruited three of their close friends (alters). Egos reported their past 30-day cannabis and alcohol use and their perceptions of alters' use. Alters also reported their actual past 30-day cannabis and alcohol use.

RESULTS

Results demonstrated that egos were very accurate in their perceptions of the frequency of alters' cannabis (ρ = 0.82, p < 0.001) and alcohol (ρ = 0.74, p < 0.001) use. Linear regression models predicted alters' actual cannabis and alcohol use based on egos' perceptions of alters' use, controlling for egos' own substance use. Egos' perceptions of alters' cannabis use strongly predicted alters' actual use (β = 0.80, p < 0.001, adj-R² = 0.67), and egos' perceptions of alters' alcohol use also predicted alters' actual use (β = 0.66, p < 0.001, adj-R² = 0.62). Egos' own substance use did not predict alters' use in either model.

CONCLUSIONS

Results provide evidence that the false consensus theory may be limited when applied to young adults with cannabis use disorder within a close-friend research framework. The results support the hypothesis that young adults are very accurate in their perceptions of the frequency of close friends' substance use and that these perceptions are independent of egos' own use. These findings support the continued use of ego-centric reported close peer substance use for understanding peer effects.

Sensation seeking to marijuana use: Exploring the mediating roles of risk appraisal and social norms

While studies have shown a robust association between sensation seeking (SS) and adolescent marijuana use, comparatively little is known about the mechanisms that potentially account for this association. The current study tests a theoretical model linking SS to marijuana use through risk appraisal and normative influences (i.e., perceived behavior and attitudes of others). Utilizing a nationally representative, cross-sectional sample of high school seniors (N = 2117), the current study finds risk appraisal and normative influences mediate the relationship between SS and marijuana use. Furthermore, perceptions of risk appear to be strongly influenced by proximal peer norms. These results indicate risk appraisal and normative processes may be key explanatory mechanisms in the association between SS and adolescent marijuana use. Theoretical and policy implications for this model are discussed.

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

PURPOSE

Substance 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.

METHODS

Data 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.

RESULTS

For 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.

CONCLUSIONS

Substance 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.

More than just Alcohol: Marijuana and Illicit Drug Use at Parties Attended by 15-20 Year Olds

BACKGROUND

Parties are a common setting for marijuana and illicit drug use among adolescents.

OBJECTIVES

This study examined the context of parties with alcohol, marijuana and illicit drug use attended by adolescents and young adults.

METHODS

In 2016, an address-based sample of 1,764 15-20-year-olds in 24 U.S. communities participated in an online survey. Parties were categorized as alcohol-only (Alc-only), marijuana + alcohol (Mj + Alc), and illicit + marijuana + alcohol (ID + Mj + Alc) based on survey participants' observations and self-reported drug use at the last party attended. Multivariable logistic regression was used to identify correlates of substance use at parties.

RESULTS

1,089 participants (61.7%) reported ever attending a party where alcohol was consumed. Of those, 60.1% reported that the last party they attended had Alc-only, 24.9% had Mj + Alc, and 10.0% had ID + Mj + Alc. Older participants were more likely to attend a party with Mj + Alc or ID + Mj + Alc. Participants whose mother had a college degree (compared to less than a college degree) were less likely to attend a party with ID + Mj + Alc. Parties with Mj + Alc and ID + Mj + Alc were larger and the majority of attendees were under 21. Parties with ID + Mj + Alc were more likely to be majority female compared to mixed gender. Parties with Mj + Alc were more likely to occur at someone else's home and be in states where medical and recreational marijuana use was legal.

CONCLUSION

One-third of parties attended by 15-20-year-olds had marijuana and/or illicit drug use in addition to alcohol consumption. The identified risk factors of parties with marijuana and illicit drug use can be used to develop targeted prevention strategies.

Sex Differences in Peer Selection and Socialization for Alcohol Use from Adolescence to Young Adulthood and the Influence of Marital and Parental Status

BACKGROUND

Peer selection and socialization influences for alcohol and other substance use have been a prominent area of research especially, though not exclusively, across adolescence. This study used 4-wave prospective data from 1,004 young adults to evaluate selection and socialization influences for young adults' alcohol use and friends' alcohol use from late adolescence to later young adulthood, and incorporated the time-varying predictors of marital and parental status. In addition, sex differences in peer selection and socialization processes were tested.

METHODS

Participants were recruited from high schools, and assessments were based on self-reports initially collected in adolescence (at age 17.0 years) via paper-and-pencil surveys and in young adulthood at ages 23.8, 28.9, and 33.5 years via computer-based individual interviews (computer-assisted personal interview and audio computer-assisted self-interviewing). Initial sampling included a 76% participation rate, and the retention rate was 83%. Cross-lagged panel regression models were used to evaluate hypotheses about peer selection and socialization.

RESULTS

Findings indicated that friend selection processes were stronger than socialization processes across adolescence to young adulthood. Adopting marital and (especially) parental roles was negatively associated with young adults' alcohol use and percentage of friends using alcohol, and the magnitude of these relationships was stronger and more consistent for females.

CONCLUSIONS

These findings indicated that across the adolescence-to-young adulthood transition, peer selection processes were more influential than peer socialization. Marital and parental roles were associated with both lower young adult alcohol use and a lower percentage of friends using alcohol, with stronger role-related effects for females relative to males.

Gender- and age-varying associations of sensation seeking and substance use across young adulthood

INTRODUCTION

Sensation seeking is associated with elevated risk for substance use among adolescents and young adults. However, whether these associations vary across age for young men and women is not well characterized.

METHODS

Using data from the Monitoring the Future (MTF) panel study, we examine the age-varying associations of sensation seeking and three types of substance use behavior (binge drinking, cigarette use, and marijuana use) across ages 18 to 30 using time-varying effect modeling. Analyses include participants in the eleven most recent MTF cohorts (12th-graders in 1994-2004), who are eligible to respond through age 29/30 (N = 6338 people; 30,237 observations).

RESULTS

While sensation seeking levels and substance use are lower among women, the magnitude of the association of sensation seeking with binge drinking and with marijuana use among women exceeds that of men in the later 20s. Differential age trends were observed; among men, the associations generally decreased or remained constant with age. Yet among women, the associations decayed more slowly or even increased with age. Specifically, the association of sensation seeking with marijuana use among women increased during the late 20s, such that the association at age 30 exceeded that in the early 20s.

CONCLUSIONS

The significantly stronger associations of sensation seeking with binge drinking and marijuana use observed among women compared to men during the mid- to late-20s suggests divergent risk factors across genders for substance use during young adulthood, with sensation seeking remaining a strong risk factor for women but not men.

Sexual Behavior and Heavy Episodic Drinking Across the Transition to Adulthood: Differences by College Attendance

Despite a growing literature on college students' sexual behaviors, little is known about how sexual behaviors, and their associations with alcohol, differ for college and noncollege attenders, and whether these patterns represent changes during college or an extension of pre-college behaviors. This paper applied time-varying effect models to data from the National Longitudinal Study of Adolescent to Adult Health to examine (1) prevalence of four sexual behaviors from ages 14 to 24 and (2) how their association with frequent heavy episodic drinking varied across these ages for college and noncollege attenders. Nonattenders have higher prevalence of all sexual behaviors than college attenders across most ages; however, the association between heavy episodic drinking and sexual behaviors is stronger for college attenders during ages 18-20.

The Influence of College Attendance on Risk for Marijuana Initiation in the United States: 1977 to 2015

OBJECTIVES

To examine a potential increase in marijuana initiation among US college students as compared with their age peers not in college before and after 2013, a watershed year for increasing tolerance of marijuana use in the United States.

METHODS

Data come from the Monitoring the Future study, which has followed longitudinal panels drawn from annual nationally representative, baseline samples of 12th-grade students starting with the class of 1976. We studied panel members aged 19 to 22 years who had never used marijuana by 12th grade between 1977 and 2015.

RESULTS

College as a risk factor for marijuana initiation has increased significantly since 2013. The increased probability of past-year marijuana use for those enrolled versus not enrolled in college was 51% in 2015, 41% in 2014, and 31% in 2013; it averaged 17% to 22% from 1977 to 2012 among youths who had never used marijuana by 12th grade.

CONCLUSIONS

College has grown as a risk factor for marijuana initiation since 2013. Public Health Implications. College students are in position to usher in new increases in population marijuana use unless colleges soon address the issue with new or modified programs for marijuana prevention and intervention.