Current patterns of marijuana use initiation by age among US adolescents and emerging adults: implications for intervention

Background: More recent data are required for effective measures to prevent marijuana use among youth in the United States. Objective: To investigate the risk of marijuana use onset by age using the most recent data from a national sample. Methods: Data for participants (n = 26,659) aged 12–21 years from the 2013 National Survey on Drug Use and Health (NSDUH) (50.4% male, 55.6% White) were analyzed. Patterns of the risk of marijuana use initiation from birth to age of 20 years by single year of age were characterized using hazards survival models. Results: The estimated hazards of marijuana use showed unique age patterns for the overall sample and by gender and racial/ethnic groups. Up to age of 11 years, the hazards of marijuana use initiation were below 0.0500; the hazards after age of 11 years increased rapidly with two peaks at age 16 (0.1291) and 18 years (0.1496), separated by a reduction at age 17 years (0.1112). The age pattern differed significantly by gender (hazards from high to low: male, female) and race/ethnicity (hazards from high to low: multi-racial, Black, White, Hispanic, and Asian). By age of 21 years, 54.1% (56.4% for male and 51.9% for female) had initiated marijuana use with a mean onset age of 16.5 years. Conclusions: This study documented the risk of marijuana use initiation by age. Research findings suggest the timing of marijuana use prevention was no later than middle school. Additional attention is indicated to multi-racial/ethnic youth. Future interventions should be developed for both parents and adolescents, and delivered to the right target population at the right time.     

A quasi-experimental evaluation of marijuana policies and youth marijuana use

Background: Marijuana use carries risks for adolescents’ well-being, making it essential to evaluate effects of recent marijuana policies.

Objectives: This study sought to delineate associations between state-level shifts in decriminalization and medical marijuana laws (MML) and adolescent marijuana use.

Methods: Using data on 861,082 adolescents (14 to 18+ years; 51% female) drawn from 1999 to 2015 state Youth Risk Behavior Surveys (YRBS), difference-in-differences models assessed how decriminalization and MML policy enactment were associated with adolescent marijuana use, controlling for tobacco and alcohol policy shifts, adolescent characteristics, and state and year trends.

Results: MML enactment was associated with small significant reductions (OR = 0.911, 95% CI [0.850, 0.975]) of 1.1 percentage points in current marijuana use, with larger significant declines for male, Black, and Hispanic (2.7–3.9 percentage points) adolescents. Effects of MML increased significantly with each year of exposure (OR = 0.980, 95% CI [0.968, 0.992]). In contrast, decriminalization was not associated with significant shifts in use for the sample as a whole, but predicted significant declines in marijuana use among 14-year olds and those of Hispanic and other ancestry (1.7–4.4 percentage points), and significant increases among white adolescents (1.6 percentage points). Neither policy was significantly associated with heavy marijuana use or the frequency of use, suggesting that heavy users may be impervious to such policy signals.

Conclusion: As the first study to concurrently assess unique effects of multiple marijuana policies, results assuage concerns over potential detrimental effects of more liberal marijuana policies on youth use.     

Local spatial clustering in youths’ use of tobacco,alcohol, and marijuana in Boston

ABSTRACT

Background: Understanding geographic variation in youth drug use is important for both identifying etiologic factors and planning prevention interventions. However, little research has examined spatial clustering of drug use among youths by using rigorous statistical methods. Objectives: The purpose of this study was to examine spatial clustering of youth use of tobacco, alcohol, and marijuana. Methods: Responses on tobacco, alcohol, and marijuana use from 1,292 high school students ages 13–19 who provided complete residential addresses were drawn from the 2008 Boston Youth Survey Geospatial Dataset. Response options on past month use included “none,” “1–2,” “3–9,” and “10 or more.” The response rate for each substance was approximately 94%. Spatial clustering of youth drug use was assessed using the spatial Bernoulli model in the SatScan? software package. Results: Approximately 12%, 36%, and 18% of youth reported any past-month use of tobacco, alcohol, and/or marijuana, respectively. Two clusters of elevated past tobacco use among Boston youths were generated, one of which was statistically significant. This cluster, located in the South Boston neighborhood, had a relative risk of 5.37 with a p-value of 0.00014. There was no significant localized spatial clustering in youth past alcohol or marijuana use in either the unadjusted or adjusted models. Conclusion: Significant spatial clustering in youth tobacco use was found. Finding a significant cluster in the South Boston neighborhood provides reason for further investigation into neighborhood characteristics that may shape adolescents' substance use behaviors. This type of research can be used to evaluate the underlying reasons behind spatial clustering of youth substance and to target local drug abuse prevention interventions and use.     

Substance Use and HIV-Risk Behaviors Among Young Men Involved in the Criminal Justice System

Objectives: We examined the relationship between substance use and sexual HIV-risk behaviors among young men who have been incarcerated, in order to understand how HIV risks develop for this vulnerable population. Methods: A sample of 552 young men in a New York City jail was interviewed at the time of incarceration. Bivariate analyses were performed to examine demographic and sexual HIV-risk behavior differences between men with and without recent alcohol and marijuana use. Logistic regression was used to examine associations between alcohol and marijuana use and sexual HIV-risk behaviors in the 90 days prior to incarceration. Results: Respondents were predominantly Black (57%) or Latino (37%), with a mean age of 17.4 years. The most common substances used were marijuana (82%) and alcohol (65%). Alcohol use prior to incarceration was significantly associated with having three or more sexual partners in the same time period (OR = 2.40, p < .001), as well as with having unprotected sex with a long-term partner (OR = 1.72, p < .01). Marijuana use was significantly associated with having multiple sex partners (OR = 1.55, p < .01). Heavy alcohol and marijuana use did not result in an increased likelihood of sexual HIV-risk behaviors. Conclusions: High rates of substance use and unprotected sex may have unintended health consequences for incarcerated young men. Severity of substance use is not a significant predictor of risk behaviors, suggesting the importance of contextual and social factors. Results highlight the need for HIV prevention efforts for this population that take into account contextual and social factors.     

Does Marijuana Use Serve as a Gateway to Cigarette Use for High-Risk African-American Youth?

Background/Objectives: The purpose of this investigation was to test whether the gateway hypothesis of drug initiation sequencing applies equally well to high-risk African-American and Caucasian youth. Methods: The study sample (N = 618, mean age = 15.5, SD = 1.2) represented the population of residents in the Missouri Division of Youth Services (DYS) who had initiated marijuana and nicotine use. Results: As hypothesized, African-American youth were significantly more likely to initiate marijuana use before cigarette use. Over one-third of African Americans reported initiating marijuana before cigarettes (37.9%), compared to less than one-quarter of youth in the other ethnic groups (Caucasian = 17.3%, Latino/Latina = 21.7%, Biracial/Other = 20.8%). Further, multinomial simulation and logistic regression models revealed that African-American youth were significantly more likely than other ethnic groups to initiate marijuana before cigarettes (Adjusted OR = 3.53, CI = 1.92–6.46). Conclusions/Scientific Significance: Findings suggest that the hypothesized gateway sequence may not apply equally well to African-Americans, and that prevention efforts based on this theory may need to be amended for these youth.     

Assessing the risk of marijuana use disorder among adolescents and adults who use marijuana

Background: The changing political and social climate surrounding marijuana use, coupled with the fact that available estimates of marijuana use disorder prevalence are outdated and do not adequately represent adolescents, underscore the need for up-to-date and comprehensive prevalence estimates of marijuana use disorder. Objectives: To provide recent national estimates of marijuana use disorder as a function of usage patterns, age, and other sociodemographic, substance use, and mental health variables. Methods: Analyses of data from the 2014 National Survey on Drug Use and Health examined the prevalence of marijuana use disorder among respondents (N = 55,271) with various sociodemographic, substance use, and mental health characteristics. Logistic and multinomial regression analyses examined the correlates of marijuana use disorder as a function of these variables, with a special focus on age. Results: In 2014, 3.49% of lifetime, 11.62% of past-year, and 15.32% of past-30-day marijuana users met DSM-IV criteria for a marijuana use disorder; rates among youth generally were at least double those of adults across reported time frame and intensity of use. Regression analyses indicated that young age, black race/ethnicity, greater intensity of use, current tobacco/nicotine use, and alcohol and other drug use disorders were associated with increased odds of a marijuana use disorder. Conclusions: A significant proportion of marijuana users, especially youth, are at risk for having a marijuana use disorder, even at relatively low levels of use.     

Effects of the “Circle of Life” HIV-prevention program on marijuana use among American Indian middle school youths: a group randomized trial in a Northern Plains tribe

Background: Early substance use threatens many American Indian/Alaska Native (AI/AN) communities, as it is a risk factor for maladaptive use and adverse health outcomes. Marijuana is among the first substances used by AI/AN youth, and its use becomes widespread during adolescence. Interventions that delay or reduce marijuana use hold the promise of curbing substance disorders and other health risk disparities in AI/AN populations. Objectives: We evaluated the effectiveness of the Circle of Life (COL) program in reducing marijuana use among young AI adolescents. COL is a culturally tailored, theory-based human immunodeficiency virus (HIV) and sexually transmitted disease (STD) intervention shown to delay sexual initiation among AI youths. Methods: We conducted secondary analyses of data from a school-based group randomized trial conducted between 2006 and 2007 in all 13 middle schools on a rural, Northern Plains reservation (N = 635, 47% female). We used discrete-time survival analysis (DTSA) to assess COL effectiveness on risk of marijuana initiation among AI youths and latent growth curve modeling (LGCM) to evaluate effects on frequency of marijuana use over time. Results: DTSA models showed that the overall risk of marijuana initiation was 17.3% lower in the COL group compared to the control group. No intervention effect on frequency of marijuana use emerged in LGCM analyses. Conclusion: COL is a multifaceted, culturally tailored, skills-based program effective in preventing marijuana uptake among AI youth.     

Employing Complier Average Causal Effect Analytic Methods to Examine Effects of Randomized Encouragement Trials

Aims: This article details the application of Complier Average Causal Effect (CACE) analysis to the examination of youth outcomes from adaptive substance use prevention trials. Methods: CACE analysis is illustrated using youth-reports of tobacco-use from ages 11 to 22, from the Adolescent Transitions Program, a family-focused randomized encouragement trial designed for delivery in the school setting Results: Female gender and early peer deviance predicted family engagement with active intervention components. Further, long-term reductions in youth tobacco use from age 11 to age 22 were found for families that engaged with treatment. Conclusions: CACE modeling techniques enable researchers to examine factors that predict engagement with core intervention components and to examine intervention effects specifically for youth who engaged with those components.     

Exploring the relationships between adolescent alcohol misuse and later life health outcomes

Background

We sought to clarify the impact of adolescent alcohol misuse on adult physical health and subjective well-being. To do so, we investigated both the direct associations between adolescent alcohol misuse and early midlife physical health and life satisfaction and the indirect effects on these outcomes attributable to subsequent alcohol problems.

Method

The sample included 2733 twin pairs (32% monozygotic; 52% female) from the FinnTwin16 study. Adolescent alcohol misuse was a composite of frequency of drunkenness, frequency of alcohol use, and alcohol problems at ages 16, 17, and 18.5. The early midlife outcomes included somatic symptoms, self-rated health, and life satisfaction at age 34. The mediators examined as part of the indirect effect analyses included alcohol problems from the Rutgers Alcohol Problem Index at ages 24 and 34. Serial mediation and co-twin comparison models were applied and included covariates from adolescence and early midlife.

Results

There were weak direct associations between adolescent alcohol misuse and early midlife physical health and life satisfaction. However, there was stronger evidence for indirect effects, whereby young adult and early midlife alcohol problems serially mediated the relationship between adolescent alcohol misuse and early midlife somatic symptoms (β = 0.03, 95% CI [0.03, 0.04]), self-rated health (β = −0.02, 95% CI [−0.03, −0.01]), and life satisfaction (β = −0.03, CI [−0.04, −0.02]). These serial mediation effects were robust in co-twin comparison analyses.

Conclusions

These results provide evidence that alcohol problems are a primary driver linking adolescent alcohol misuse and poor health outcomes across the lifespan.     

Patterns of simultaneous and concurrent alcohol and marijuana use among adolescents

Background: Alcohol and marijuana are the most commonly used substances among adolescents but little is known about patterns of co-use. Objectives: This study examined patterns of concurrent (not overlapping) and simultaneous (overlapping) use of alcohol and marijuana among adolescents. Methods: Data from US-national samples of 12th graders (N = 84,805, 48.4% female) who participated in the Monitoring the Future study from 1976 to 2016 and who used alcohol and/or marijuana in the past 12 months were used to identify latent classes of alcohol use, marijuana use, and simultaneous alcohol and marijuana (SAM) use. Results: A four-class solution indicated four patterns of use among adolescents: (1) Simultaneous alcohol and marijuana (SAM) use with binge drinking and recent marijuana use (SAM-Heavier Use; 11.2%); (2) SAM use without binge drinking and with recent marijuana use (SAM-Lighter Use; 21.6%); (3) Marijuana use and alcohol use but no SAM use (Concurrent Use; 10.7%); and (4) Alcohol use but no marijuana or SAM use (Alcohol-Only Use; 56.4%). Membership in either SAM use class was associated with a higher likelihood of truancy, evenings out, and use of illicit drugs other than marijuana. SAM-Heavier Use, compared to SAM-Lighter Use, class members were more likely to report these behaviors and be male, and less likely to have college plans. Conclusions: Among 12th graders who use both alcohol and marijuana, the majority use simultaneously, although not all use heavily. Given the recognized increased public health risks associated with simultaneous use, adolescent prevention programming should include focus on particular risks of simultaneous use.     

Testing a causal model of environmental influences on the early drug involvement of inner city junior high school youths

The present study examines a causal model explaining inner city youths' drug involvement using environmental variables which previously have been investigated singly or in various combinations and shown to influence drug use: the availability of drugs in the neighborhood and at school, a view of the neighborhood as tough, the esteem given to drug using, gang-involved persons by peers, friends' substance use, and participation in drug/street culture spare-time activities. The results show friends' use of alcohol and marijuana and participation in drug/street culture out-of-school activities have strong direct effects on personal drug involvement for the Black and Puerto Rican junior high school males and females who were studied; further, friends' use of alcohol and marijuana and the status peers give to drug using, gang-involved persons have respectable indirect effects on drug involvement for the four groups. In addition to these common features, a number of differences in the factors relating to drug involvement are found in the four groups. Implications of the results for alternative methods of drug abuse prevention and treatment are discussed, as is the necessity of utilizing an environmental, sociocultural view of drug use to adequately explain youth drug taking.     

Substance use among bi/multiracial youth in the United States: Profiles of psychosocial risk and protection

Background: Bi/multiracial youth face higher risk of engaging in substance use than most monoracial youth. Objectives: This study contrasts the prevalence of substance use among bi/multiracial youth with that of youth from other racial/ethnic groups, and identifies distinct profiles of bi/multiracial youth by examining their substance use risk. Methods: Using data from the National Survey on Drug Use and Health (collected between 2002 and 2014), we analyze data for 9,339 bi/multiracial youth ages 12–17 living in the United States. Analyses use multinomial regression and latent class analysis. Results: With few exceptions, bi/multiracial youth in general report higher levels of tobacco, alcohol, marijuana, and other illicit drug use compared to other youth of color. Bi/multiracial youth also report higher levels of marijuana use compared to non-Hispanic white adolescents. However, latent class modeling also revealed that a majority (54%) of bi/multiracial youth experience high levels of psychosocial protection (i.e., strong antidrug views and elevated parental engagement) and low levels of psychosocial risk (i.e., low peer substance use, school-related problems, and social-environmental risk), and report very low levels of substance use. Substance use was found to be particularly elevated among a minority of bi/multiracial youth (28%) reporting elevated psychosocial risk and low levels of protection. Bi/multiracial youth characterized by both elevated psychosocial risk and elevated psychosocial protection (22%) reported significantly elevated substance use as well. Conclusions: While bi/multiracial youth in general exhibit elevated levels of substance use, substantial heterogeneity exists among this rapidly-growing demographic.     

Risk and protective factors for heavy binge alcohol use among American Indian adolescents utilizing emergency health services

Background: American Indian (AI) adolescents are disproportionately burdened by alcohol abuse and heavy binge use, often leading to problematic drinking in adulthood. However, many AI communities also have large proportions of adults who abstain from alcohol. Objective: To understand these concurrent and divergent patterns, we explored the relationship between risk and protective factors for heavy binge alcohol use among a reservation-based sample of AI adolescents. Methods: Factors at individual, peer, family, and cultural/community levels were examined using a cross-sectional case–control study design. Cases were adolescents with recent heavy binge alcohol use that resulted in necessary medical care. Controls had no lifetime history of heavy binge alcohol use. 68 cases and 55 controls were recruited from emergency health services visits. Participants were 50% male; average age 15.4 years old, range 10 to 19. Independent variables were explored using logistic regression; those statistically significant were combined into a larger multivariate model. Results: Exploratory analyses showed adolescents who were aggressive, impulsive, had deviant peers, poor family functioning or more people living at home were at greater risk for heavy binge alcohol use. Protective factors included attending school, family closeness, residential stability, social problem-solving skills, having traditional AI values and practices, and strong ethnic identity. Confirmatory analysis concluded that school attendance and residential stability reduce the probability of heavy binge alcohol use, even among those already at low risk. Conclusions: Findings deepen the understanding of AI adolescent heavy binge alcohol use and inform adolescent intervention development fostering trajectories to low-risk drinking and abstinence.     

Rural and urban substance use differences: Effects of the transition to college

Background: With approximately 20% of Americans residing in rural communities, substance use differences is an important topic for appropriate use of resources, policy decisions, and the development of prevention and intervention programs. Objectives: The current study examined differences in alcohol, tobacco, and marijuana use among students from rural and urban backgrounds across the transition to college. Methods: Participants were 431 (48% male) undergraduate students from a large, public southeastern university who provided yearly alcohol, tobacco, and marijuana use data during freshman, sophomore, and junior years. Results: Prevalence of alcohol, tobacco, and marijuana use was lower during early college years, and females were less likely to use tobacco and marijuana. Results indicated that rural individuals were less likely to use alcohol and marijuana than their urban counterparts as freshmen, but rose to meet the rates of urban students by junior year. In contrast, no rural/urban differences in tobacco were noted, although rural minorities were more likely to endorse tobacco use across all years. Finally, perceived peer use of each substance was a significant predictor of future use of that substance for all years. Conclusion: This is the first study to explore rural/urban, gender, and racial differences in substance use across the college transition. Results suggest that there are subgroups of individuals at specific risk who may benefit not only from feedback regarding the influence of perceived peer use in college, but also from a deeper understanding of how cultural norms maintain their substance use behaviors over time.     

Characteristic substance misuse profiles among youth entering an urban emergency department: neighborhood correlates and behavioral comorbidities

Background: Little is known about characteristic profiles of substance use – and their individual- and neighborhood-level correlates – among high-risk youth. Objectives: To identify characteristic substance misuse profiles among youth entering an urban emergency department (ED) and explore how those profiles relate to individual- and community-level factors. Methods: Individual-level measures came from screening surveys administered to youth aged 14–24 at an ED in Flint, Michigan (n = 878); alcohol outlet and crime data came from public sources. Binary misuse indicators were generated by using previously established cut-points on scores of alcohol and drug use severity. Latent class analysis (LCA) identified classes of substance use; univariate tests and multinomial models identified correlates of class membership. Results: Excluding non-misusers (51.5%), LCA identified three classes: marijuana-only (27.9%), alcohol/marijuana (16.1%), and multiple substances (polysubstance) (4.6%). Moving from non-misusers to polysubstance misusers, there was an increasing trend in rates of: unprotected sex, motor vehicle crash, serious violence, weapon aggression, and victimization (all p < .001). Controlling for individual-level variables, polysubstance misusers lived near more on-premises alcohol outlets than non-misusers (RRR = 1.42, p = .01) and marijuana-only misusers (RRR = 1.31, p = .03). Alcohol/marijuana misusers were more likely to live near high violent crime density areas than non-misusers (RRR = 1.83, p = .01), and were also more likely than marijuana-only misusers to live in areas of high drug crime density (RRR = 1.98, p = .03). No other relationships were significant. Conclusion: Substance-misusing youth seeking ED care have higher risk for other problem behaviors and neighborhood-level features display potential for distinguishing between use classes. Additional research to elucidate at-risk sub-populations/locales has potential to improve interventions for substance misuse by incorporating geographic information.     

Adolescent substance abuse: the effects of alcohol and marijuana on neuropsychological performance

Background: Adolescence is a period in which cognition and brain undergo dramatic parallel development. Whereas chronic use of alcohol and marijuana is known to cause cognitive impairments in adults, far less is known about the effect of these substances of abuse on adolescent cognition, including possible interactions with developmental processes. Methods: Neuropsychological performance, alcohol use, and marijuana use were assessed in 48 adolescents (ages 12 to 18), recruited in 3 groups: a healthy control group (HC, n = 15), a group diagnosed with substance abuse or dependence (SUD, n = 19), and a group with a family history positive for alcohol use disorder (AUD) but no personal substance use disorder (FHP, n = 14). Age, drinks per drinking day (DPDD), percentage days drinking, and percentage days using marijuana were considered as covariates in a MANCOVA in which 6 neuropsychological composites (Verbal Reasoning, Visuospatial Ability, Executive Function, Memory, Attention, and Processing Speed) served as dependent variables. Results: More DPDD predicted poorer performance on Attention and Executive Function composites, and more frequent use of marijuana was associated with poorer Memory performance. In separate analyses, adolescents in the SUD group had lower scores on Attention, Memory, and Processing Speed composites, and FHP adolescents had poorer Visuospatial Ability. Conclusions: In combination, these analyses suggest that heavy alcohol use in adolescence leads to reduction in attention and executive functioning and that marijuana use exerts an independent deleterious effect on memory. At the same time, premorbid deficits associated with family history of AUD appeared to be specific to visuospatial ability.     

Cumulative Marijuana Use and Carotid Intima-Media Thickness at Middle Age: The CARDIA Study

BackgroundLong-term cardiovascular health effects of marijuana are understudied. Future cardiovascular disease is often indicated by subclinical atherosclerosis for which carotid intima-media thickness is an established parameter.MethodsUsing the data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a cohort of 5115 Black and white women and men at Year 20 visit, we studied the association between carotid intima-media thickness in midlife and lifetime exposure to marijuana (1 marijuana year = 365 days of use) and tobacco smoking (1 pack-year = 20 cigarettes/day for 365 days). We measured carotid intima-media thickness by ultrasound and defined high carotid intima-media thickness at the threshold of the 75th percentile of all examined participants. We fit logistic regression models stratified by tobacco smoking exposure, adjusting for demographics, cardiovascular risk factors, and other drug exposures.ResultsData was complete for 3257 participants; 2722 (84%) reported ever marijuana use; 374 (11%) were current users; 1539 (47%) reported ever tobacco smoking; 610 (19%) were current smokers. Multivariable adjusted models showed no association between cumulative marijuana exposure and high carotid intima-media thickness in never or ever tobacco smokers, odds ratio (OR) 0.87 (95% confidence interval [CI]: 0.63-1.21) at 1 marijuana-year among never smokers and OR 1.11 (95% CI: 0.85-1.45) among ever tobacco smokers. Cumulative exposure to tobacco was strongly associated with high carotid intima-media thickness, OR 1.88 (95%CI: 1.20-2.94) for 20 pack-years of exposure.ConclusionsThis study adds to the growing body of evidence that there might be no association between the average population level of marijuana use and subclinical atherosclerosis.     

A longitudinal study of substance use and violent victimization in adulthood among a cohort of urban African Americans

Aims This paper examines the effects of experiencing violent victimization in young adulthood on pathways of substance use from adolescence to mid‐adulthood. Design Data come from four assessments of an African American community cohort followed longitudinally from age 6 to 42 years. Setting The cohort lived in the urban, disadvantaged Woodlawn neighborhood of Chicago in 1966. Participants All first graders from the public and parochial schools were asked to participate (n = 1242). Measurement Dependent variables—alcohol, marijuana and cocaine use—came from self‐reports at age 42. Young adult violent victimization was reported at age 32, as were acts of violence, substance use, social integration and socio‐economic resources. First grade risk factors came from mothers' and teachers' reports; adolescent substance use was self‐reported. Findings Structural equation models indicate a pathway from adolescent substance use to young adult violent victimization for females and those who did not grow up in extreme poverty (betas ranging from 0.15 to 0.20, P < 0.05). In turn, experiencing violent victimization in young adulthood increased alcohol, marijuana and cocaine use, yet results varied by gender and early poverty status (betas ranging from 0.12 to 0.15, P < 0.05). Conclusions Violent victimization appears to play an important role in perpetuating substance use among the African American population. However, within‐group variations are evident, identifying those who are not raised in extreme poverty as the most negatively affected by violence.     

Selection and socialization effects of fraternities and sororities on US college student substance use: a multi-cohort national longitudinal study

AIMS: To examine how membership in fraternities and sororities relates to the prevalence and patterns of substance use in a national sample of full-time US college students. DESIGN: Nationally representative probability samples of US high school seniors (modal age 18 years) were followed longitudinally across two follow-up waves during college (modal ages 19/20 and 21/22). SETTING: Data were collected via self-administered questionnaires from US high school seniors and college students. PARTICIPANTS: The longitudinal sample consisted of 10 cohorts (senior years of 1988-97) made up of 5883 full-time undergraduate students, of whom 58% were women and 17% were active members of fraternities or sororities. FINDINGS: Active members of fraternities and sororities had higher levels of heavy episodic drinking, annual marijuana use and current cigarette smoking than non-members at all three waves. Although members of fraternities reported higher levels than non-members of annual illicit drug use other than marijuana, no such differences existed between sorority members and non-members. Heavy episodic drinking and annual marijuana use increased significantly with age among members of fraternities or sororities relative to non-members, but there were no such differential changes for current cigarette use or annual illicit drug use other than marijuana. CONCLUSIONS: The present study provides strong evidence that higher rates of substance use among US college students who join fraternities and sororities predate their college attendance, and that membership in a fraternity or sorority is associated with considerably greater than average increases in heavy episodic drinking and annual marijuana use during college. These findings have important implications for prevention and intervention efforts aimed toward college students, especially members of fraternities and sororities.