Abstract
Introduction
This study examined the associations between psychosocial factors and status of marijuana use: former experimentation, current occasional, and current frequent use.
Methods
Data were collected from a nationally-representative sample of U.S. tenth-graders who participated in the 2005/6 Health Behavior in School-aged Children Study (n=1,465). Multinomial regressions, run separately by gender, examined the association of risk and protective factors from the individual (life satisfaction; academic achievement; aggression, bullying) and contextual (mothers and fathers' knowledge of adolescents' activities, school climate) domains with status of marijuana use (former experimentation, current occasional use, current frequent use).
Results
Former experimental and current marijuana use were negatively associated with protective factors such as academic achievement, mothers' and fathers' knowledge of adolescents' activities, and life satisfaction, but not with positive school climate. Former experimental and current marijuana use were positively associated with aggression and bullying perpetration. Most associations varied by gender and status of marijuana use. In adjusted analyses, aggression emerged as the sole risk factor and fathers' knowledge as the sole protective factor that were positively associated with most statuses of marijuana use, across gender.
Conclusion
Fathers may be particularly important in preventing adolescent marijuana use, and interventions promoting fathers' knowledge of adolescents' activities are warranted.
Keywords: marijuana use, experimentation, psychosocial correlates, gender differences
1. Introduction
Marijuana is the most widely used illicit drug among U.S. adolescents, with 14.2% of tenth-graders reporting past 30-day use in 2008 (Johnston, O'Malley, Bachman, & Schulenberg, 2009). Adolescent marijuana use has been linked to adverse outcomes including elevated depression, conduct problems, and low education achievement (Fergusson, Horwood, & Beautrais, 2003; Hall, 2006; Wittchen et al., 2007), as well as increased risks for dependence compared to later initiation (Fergusson, Horwood, Lynskey, & Madden, 2003; Schneider, 2008). Yet few studies have examined status-specific psychosocial correlates of marijuana use for former experimental, current occasional and more frequent users.
Guided by problem behavior theory (Jessor, 1991), this study focused on individual and contextual correlates that either have been less extensively studied in relation to marijuana use, although their association with other substances has been established (parental knowledge of adolescents' activities, bullying, aggression), or because previous research documenting their association with different degrees of involvement with marijuana is inconclusive (life satisfaction, academic achievement, school climate).
Three hypotheses were examined. First, we hypothesized that former experimental, current occasional and current heavy marijuana use would be negatively associated with protective factors (life satisfaction, academic achievement, mothers' and fathers' knowledge of adolescents' activities, and positive school climate) and positively associated with risk behaviors (aggression and bullying). Second, we expected that the hypothesized associations would vary by status of marijuana use, as suggested by previous research (Monshouwer et al., 2006). Third, we anticipated gender differences in the hypothesized associations, given past findings of gender differences in the association of psychosocial correlates and marijuana use (Brook et al., 1998; Tu, Ratner, & Johnson, 2008).
2. Methods
2.1 Sample and Procedures
The US 2005/6 Health Behavior in School-Aged Children (HBSC) study is a survey of a nationally-representative, school-based sample conducted every four years. More information on methods and procedures can be found at www.hbsc.org (Currie et al., 2008a). A three-stage stratified clustered sampling, with classes as the sampling units, was used to select a nationally representative sample of students in grades 6-10. African-American and Hispanic students were oversampled. Data were collected through self-report questionnaires distributed in the classrooms and respondents' anonymity was ensured. The Institutional Review Board at the Eunice Kennedy Shriver National Institute of Child Health and Human Development approved the survey.
Of all selected students, 85% (n=9,016) completed the questionnaire. Because of low prevalence of marijuana use among younger adolescents, we restricted the sample to tenth-graders (mean age=16) who had complete data on marijuana use and all predictors and covariates of interest. The final sample included 1,465 students.
2.2 Measures
Marijuana use was measured by combining respondents' answers to two questions, asking about marijuana use in their life and in the last 30 days. Response items ranged from “Never” to “40 times or more.” Respondents who answered “Never” to lifetime and 30-day use were considered never users; those who reported using at least once in their lifetime but never in the past 30 days were considered former experimental users; respondents who reported using once or twice in the past 30 days were considered current occasional users; respondents who reported using 3 or more times in the past 30 days were considered current frequent users.
Academic achievement
Respondents specified, on a 4-point scale (1=below average, 4=very good) what their teachers might think about their school performance compared to their classmates.
Life satisfaction was measured on a 10-point ladder (0=worst possible life; 10=best possible life).
Mothers' knowledge was the mean of five items (α=.77). For each item, respondents reported, on a 4-point scale (1=don't have/see mother; 4=knows a lot) how much their mother/stepmother knows about their activities.
Fathers' knowledge was computed similarly to mothers' knowledge (α=.88).
School climate was the average of three items. Respondents indicated how much they agreed/disagreed (1=strongly agree; 5=strongly disagree) with statements about the students in their class (α=.70). Higher scores indicate a more negative school climate.
Aggression
The aggression scale was created by summing the answers to questions about physical fighting and weapon carrying. Respondents reported the frequency with which they carried a weapon during the last 30 days (response options: “I did not carry a weapon” to “6 or more days”). Respondents also indicated how often they had been involved in a physical fight in the past 12 months (response options: “I have not been in a physical fight,” to “4 times or more”). Higher scores indicate greater aggression.
Bullying
Involvement in bullying was measured by two questions asking the frequency with which respondents bullied others or were bullied in the past couple of months. Response items ranged from “I haven't been bullied/haven't bullied another student at school the past couple of months” to “several times a week.” Respondents were categorized as “victims” if they only reported bullying victimization (at least once or twice in the past couple of months); “perpetrators” if they only reported bullying perpetration; “victim-perpetrators” if they reported both bullying victimization and perpetration; and “not involved” if they reported neither.
Demographic characteristics included gender, race/ethnicity (White/Black/Hispanic/Other), family composition (one parent/two parents/other) and a family affluence scale (FAS), an indicator of adolescents' socioeconomic status constructed from questions about family wealth and categorized into tertiles (Currie et al., 2008b).
2.3 Analysis Strategy
All analyses were conducted using Stata 9 to adjust for the cluster-based sampling design of HBSC. Weights were applied to provide nationally representative estimates. Descriptive statistics were computed for all variables. Multinomial logistic regression models, separately for each predictor, then examined the association between each predictor and marijuana use, controlling for sociodemographics. Finally, multivariable models, separately by gender, regressed marijuana use jointly on all psychosocial factors, controlling for sociodemographics.
3. Results
3.1 Study Sample
The sample was approximately half boys and half girls. Most respondents were non-Hispanic Whites, lived in two-parent families, and were of medium socioeconomic status (Table 1). Almost two thirds of respondents had never used marijuana, 18% were former experimental users, 8% current occasional users and 8% current frequent users.
Table 1. Prevalence and means for the sample demographic characteristics and psychosocial correlates, by gender (n=1465).
| Total (n=1465) | Boys (n=726) | Girls (n=739) | ||||
|---|---|---|---|---|---|---|
| % | n | % | n | % | n | |
| Marijuana use | ||||||
| Never use | 63.40 | 904 | 60.33 | 427 | 66.34 | 477 |
| Former experimental use | 18.59 | 295 | 18.98 | 148 | 18.21 | 147 |
| Current occasional use | 7.85 | 106 | 7.88 | 52 | 7.82 | 54 |
| Current frequent use | 10.17 | 160 | 12.81 | 99 | 7.63 | 61 |
| Bullying | ||||||
| None | 55.84 | 819 | 53.66 | 378 | 57.93 | 441 |
| Perpetrator | 8.76 | 141 | 7.72 | 67 | 9.75 | 74 |
| Victim | 24.09 | 350 | 26.45 | 198 | 21.82 | 152 |
| Victim-perpetrator | 11.32 | 155 | 12.17 | 83 | 10.49 | 72 |
| Race/ethnicity | ||||||
| White | 46.98 | 752 | 48.95 | 378 | 45.09 | 374 |
| Black | 18.29 | 287 | 17.05 | 138 | 19.48 | 149 |
| Hispanic | 23.32 | 290 | 21.84 | 132 | 24.75 | 158 |
| Other | 11.41 | 136 | 12.16 | 78 | 10.69 | 58 |
| FAS | ||||||
| Low | 27.68 | 400 | 26.27 | 189 | 29.04 | 211 |
| Medium | 49.09 | 741 | 50.37 | 369 | 47.87 | 372 |
| High | 23.22 | 324 | 23.36 | 168 | 23.09 | 156 |
| Family composition | ||||||
| One parent | 23.23 | 335 | 21.64 | 160 | 24.75 | 175 |
| Two parents | 71.65 | 1050 | 73.41 | 522 | 69.96 | 528 |
| Other | 5.12 | 80 | 4.95 | 44 | 5.29 | 36 |
| Total (n=1465) | Boys (n=726) | Girls (n=739) | ||||
| Mean | SE | Mean | SE | Mean | SE | |
| Aggression | 2.92 | 0.07 | 3.24 | 0.09 | 2.61 | 0.08 |
| Mothers' knowledge | 17.37 | 0.10 | 17.17 | 0.13 | 17.56 | 0.14 |
| Fathers' knowledge | 14.49 | 0.20 | 14.79 | 0.31 | 14.19 | 0.21 |
| School climate | 2.47 | 0.04 | 2.43 | 0.05 | 2.51 | 0.05 |
| Life satisfaction | 7.32 | 0.07 | 7.39 | 0.09 | 7.25 | 0.10 |
| Academic achievement | 2.81 | 0.05 | 2.72 | 0.06 | 2.89 | 0.06 |
3.2 Results from Multivariate Analyses
Because the results from the predictor-specific models were similar to those of the final model, we only present the results of the final models. These models show that the odds of marijuana use increased with aggression among boys and girls, with the exception of boys' current occasional use (Table 2). A higher fathers' knowledge of adolescents' activities was associated with a lower odds of former experimental and current marijuana use for boys and girls, except for boys' experimental use. The associations of all other risk and protective correlates with marijuana use differed by gender and status of use. Mothers' knowledge of adolescents' activities was associated with lower odds of current frequent use (boys and girls), current occasional use (boys) and former experimental use (girls). Higher academic achievement was associated with lower odds of experimental and current frequent use only among boys. Conversely, better life satisfaction was negatively associated with current frequent use, only among girls. Bullying perpetration was associated with higher odds of experimental use, whereas being a bully victim-perpetrator was correlated with lower odds of current occasional use, for boys and girls. Worse perceptions of the school climate were associated with lower odds of experimental marijuana use, only among girls.
Table 2. Adjusted odds ratios estimates for the association of psychosocial correlates with marijuana use, by gender a.
| Marijuana use b | ||||||
|---|---|---|---|---|---|---|
| Boys (n=726) | Girls (n=739) | |||||
| Former experimental AOR (95%CI) | Current occasional AOR (95%CI) | Current frequent AOR (95%CI) | Former experimental AOR (95%CI) | Current occasional AOR (95%CI) | Current frequent AOR (95%CI) | |
| Aggression | 1.18 (1.01-1.37) | 1.05(0.86-1.27) | 1.45(1.19-1.76) | 1.40(1.15-1.69) | 1.44(1.12-1.87) | 1.50(1.09-2.07) |
| Bullying | ||||||
| No bullying | Referent | Referent | Referent | Referent | Referent | Referent |
| Victim | 1.76 (0.61-5.09) | 0.96(0.01-0.74) | 0.93(0.19-4.55) | 1.51(0.66-3.43) | 0.07(0.01-0.58) | 0.52(0.17-1.66) |
| Perpetrator | 1.52(0.85-2.69) | 2.10(0.82-5.38) | 1.60(0.84-3.04) | 2.30(1.23-4.31) | 1.34(0.58-3.09) | 1.53(0.64-3.64) |
| Victim - perpetrator | 1.01(0.42-2.46) | 2.39(0.52-10.96) | 1.19(0.46-3.12) | 1.13(0.38-3.33) | 3.33(1.35-8.20) | 0.61(0.12-3.15) |
| Life satisfaction | 1.11(0.95-1.31) | 1.08(0.88-1.33) | 1.05(0.86-1.29) | 0.90(0.75-1.08) | 1.04(0.88-1.24) | 0.80(0.66-0.98) |
| Academic achievement | 0.61(0.47-0.78) | 0.78(0.44-1.39) | 0.59(0.43-0.81) | 0.81(0.61-1.09) | 0.79(0.56-1.12) | 0.82(0.53-1.27) |
| Mothers' knowledge | 0.94(0.85-1.03) | 0.84(0.72-0.98) | 0.77(0.67-0.87) | 0.91(0.83-0.99) | 0.91(0.81-1.01) | 0.81(0.71-0.93) |
| Fathers' knowledge | 0.93(0.86-1.00) | 0.85(0.76-0.94) | 0.86(0.78-0.95) | 0.88(0.82-0.93) | 0.93(0.86-0.99) | 0.84(0.76-0.94) |
| School climate | 1.08(0.76-1.54) | 0.80(0.41-1.59) | 1.29(0.82-2.04) | 0.54(0.38-0.77) | 1.19(0.77-1.84) | 0.64(0.39-1.05) |
Model controls for FAS, race/ethnicity and family composition
No marijuana use is the reference category
4. Discussion
Our analyses of a representative population-based sample of US tenth-graders indicate significant differences in psychosocial correlates of marijuana use by gender and status of use. Consistent with our first hypothesis, our results show that former experimental and current marijuana use were negatively associated with protective factors such as academic achievement, mothers' and fathers' knowledge of adolescents' activities and life satisfaction, but not with a positive school climate. Former experimental and current use were also positively associated with risk behaviors such as aggression and bullying. We further found support for our second and third hypotheses of differential associations by gender and type of involvement.
Aggression emerged as a psychosocial risk factor for all but one status of marijuana use across gender. These findings support previous research showing a positive association between aggressive behavior and marijuana initiation among boys (Korhonen et al., 2008) and girls (van den Bree et al., 2005). However, in contrast to findings from a US national sample (e.g., van den Bree et al., 2005), our study showed that aggression is also linked to marijuana experimentation for both genders. It is unclear how aggression and marijuana are associated. It seems most likely that they share common determinants or possibly the experience of one of these behaviors may contribute to the likelihood of occurrence of the other (Fergusson, Horwood, & Swain-Campbell, 2002). While these findings do not permit the conclusion of a cause-and-effect association, they do imply that aggression and marijuana use co-occur and that prevention programs targeted at one could affect the other.
Fathers' knowledge of adolescents' activities was significantly protective for all but one status of marijuana use for boys and girls. Compared to mothers' knowledge, surprisingly little is known on fathers' knowledge because studies examining the effect of parenting practices on substance use have either looked at the protective effect of mothers' knowledge only or at that of a combined measure of parental knowledge. Fathers' knowledge of adolescents' activities is achieved through a variety of methods including adolescents' disclosure of information, observation or third-party (e.g., friends) reports of adolescents' activities, or by asking the mothers (Waizenhofer et al., 2004). Fathers' knowledge may influence adolescents' beliefs about marijuana use, which could, in turn, affect their intentions to use and, ultimately, their use (Lac et al., 2009). Further investigation of the mechanism of influence of fathers' knowledge should be the focus of future research, as this information could inform family-based prevention programs.
Other gender- and status-specific correlates of marijuana use included academic achievement, school climate, and bullying perpetration. Academic achievement emerged as the only boy-specific protective factor, confirming previous findings among a Swiss national sample (Stronski, Ireland, Michaud, Narring, & Resnick, 2000). Our results indicated that a negative school climate decreased girls' risk of marijuana experimentation, while bullying perpetration doubled their risk. Our findings differ from a previous study showing that school-related problems were associated with marijuana use across gender and stage of use (van den Bree et al., 2005). These differences may stem from the different measures used to assess school problems that could differentially affect boys' and girls' marijuana use. Bullying perpetration's association with girls' marijuana experimentation supports previous findings of the association of bullying perpetration with substance use (Carlyle et al., 2007; Bolognini et al., 2007). However, more research is needed to clarify why this association did not hold for girls' current use or for boys' use.
This study has many strengths, including the use of a large and nationally representative sample of US tenth-graders, the investigation of individual and contextual risk and protective correlates of marijuana use that had not been well documented in existing literature, and assessing commonalities and differences in these correlates by status of marijuana use.
However, some limitations should be considered, including the cross-sectional nature of the data that makes it difficult to test for the temporal sequence of these events and the study's reliance on adolescents' retrospective reports of marijuana use, rather than prospective measures.
This study has implications for the prevention of adolescent marijuana use. Our analyses indicate that aggression and, to a lesser extent and only among girls, bullying perpetration, are a source of concern because of their association with marijuana experimentation, current occasional and current frequent use. While aggressive behavior and bullying perpetration may not directly lead to marijuana use, these behaviors tend to co-occur and could reflect underlying risk factors associated with both behaviors (e.g., risk-taking personalities), as posited by problem behavior theory. Our findings suggest that intervention programs for problem behavior that address key determinants, such as parental knowledge, may prevent marijuana use and other problem behaviors among both boys and girls. Designing prevention programs that comprehensively address these multiple factors could prove cost-effective by reaching out to a wide population at risk for marijuana experimentation or current use.
Research Highlights.
Fathers' knowledge of adolescents' activities is protective against most statuses of marijuana use, across gender
Association of aggression with marijuana use could reflect an underlying structure of risk behavior
Most risk and protective factors against marijuana use vary by gender and status of use
Acknowledgments
Role of Funding Sources: This research was supported in part by the intramural research program of the National Institutes of Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) (Contract # N01-HD-5-3401) and the Maternal and Child Health Bureau of the Health Resources and Services Administration (HRSA). NICHD and HRSA had no role in the study design, collection, analysis or interpretation of the data, writing the manuscript, or the decision to submit the paper for publication.
Footnotes
Contributors: Tilda Farhat, Bruce Simons-Morton and Jeremy Luk contributed to the conception and design of the study, interpretation of the data and writing of the manuscript. Tilda Farhat conducted the statistical analyses. All authors have approved the final manuscript.
Conflict of Interest: The authors have no conflict of interest to declare.
Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
References
- Bolognini M, Plancherel B, Winnington ME, Bernard M, Stephan P, Halfon O. Substance use early initiation among violent and nonviolent antisocial adolescents. Addiction Research & Theory. 2007;15:561–574. [Google Scholar]
- Brook JS, Brook DW, De la Rosa M, Duque LF, Rodriguez E, Montoya ID, et al. Pathways to marijuana use among adolescents: Cultural/ecological, family, peer, and personality influences. Journal of the American Academy of Child and Adolescent Psychiatry. 1998;37:759–766. [PubMed] [Google Scholar]
- Carlyle KE, Steinman KJ. Demographic differences in the prevalence, co-occurrence, and correlates of adolescent bullying at school. Journal of School Health. 2007;77:623–629. doi: 10.1111/j.1746-1561.2007.00242.x. [DOI] [PubMed] [Google Scholar]
- Currie C, Gabhainn SN, Godeau E, Roberts C, Smith R, Currie D, et al. Researching Inequalities in young people's health: HBSC international report from the 2005/2006 survey. WHO Regional Office for Europe; 2008a. [Google Scholar]
- Currie C, Molcho M, Boyce W, Holstein B, Torsheim T, Richter M. Researching health inequalities in adolescents: The development of the Health Behaviour in School-Aged Children (HBSC) Family Affluence Scale. Social science & medicine. 2008b;66:1429–1436. doi: 10.1016/j.socscimed.2007.11.024. [DOI] [PubMed] [Google Scholar]
- Fergusson DM, Horwood LJ, Beautrais AL. Cannabis and educational achievement. Addiction. 2003;98:1681–1692. doi: 10.1111/j.1360-0443.2003.00573.x. [DOI] [PubMed] [Google Scholar]
- Fergusson DM, Horwood LJ, Lynskey MT, Madden PAF. Early reactions to cannabis predict later dependence. Archives of general psychiatry. 2003;60:1033–1039. doi: 10.1001/archpsyc.60.10.1033. [DOI] [PubMed] [Google Scholar]
- Fergusson DM, Horwood LJ, Swain-Campbell N. Cannabis use and psychosocial adjustment in adolescence and young adulthood. Addiction. 2002;97:1123–1135. doi: 10.1046/j.1360-0443.2002.00103.x. [DOI] [PubMed] [Google Scholar]
- Hall WD. Cannabis use and the mental health of young people. Australian and New Zealand Journal of Psychiatry. 2006;40:105–113. doi: 10.1080/j.1440-1614.2006.01756.x. [DOI] [PubMed] [Google Scholar]
- Jessor R. Risk Behavior in Adolescence - A Psychosocial Framework for Understanding and Action. Journal of Adolescent Health. 1991;12:597–605. doi: 10.1016/1054-139x(91)90007-k. [DOI] [PubMed] [Google Scholar]
- Johnston LD, O'Malley PM, Bachman JG, Schulenberg JE. Monitoring the Future national results on adolescent drug use: Overview of key findings, 2008 (Rep No NIH Publication No 09-7401) Bethesda, MD: National Institute on Drug Abuse; 2009. [Google Scholar]
- Korhonen T, Huizink AC, Dick DM, Pulkkinen L, Rose RJ, Kaprio J. Role of individual, peer and family factors in the use of cannabis and other illicit drugs: A longitudinal analysis among Finnish adolescent twins. Drug and Alcohol Dependence. 2008;97:33–43. doi: 10.1016/j.drugalcdep.2008.03.015. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lac A, Alvaro EM, Crano WD, Siegel JT. Pathways from Parental Knowledge and Warmth to Adolescent Marijuana Use: An Extension to the Theory of Planned Behavior. Prevention Science. 2009;10:22–32. doi: 10.1007/s11121-008-0111-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Monshouwer K, Van Dorsselaer S, Verdurmen J, ter Bogt T, De Graaf R, Vollebergh W. Cannabis use and mental health in secondary school children. Findings from a Dutch survey. British Journal of Psychiatry. 2006;188:148–153. doi: 10.1192/bjp.188.2.148. [DOI] [PubMed] [Google Scholar]
- Schneider M. Puberty as a highly vulnerable developmental period for the consequences of cannabis exposure. Addiction Biology. 2008;13:253–263. doi: 10.1111/j.1369-1600.2008.00110.x. [DOI] [PubMed] [Google Scholar]
- Stronski SM, Ireland M, Michaud PA, Narring F, Resnick MD. Protective correlates of stages in adolescent substance use: A Swiss national study. Journal of Adolescent Health. 2000;26:420–427. doi: 10.1016/s1054-139x(99)00057-9. [DOI] [PubMed] [Google Scholar]
- Tu AW, Ratner PA, Johnson JL. Gender differences in the correlates of adolescents' cannabis use. Substance Use & Misuse. 2008;43:1438–1463. doi: 10.1080/10826080802238140. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Van den Bree MBM, Pickworth WB. Risk factors predicting changes in marijuana involvement in teenagers. Archives of general psychiatry. 2005;62:311–319. doi: 10.1001/archpsyc.62.3.311. [DOI] [PubMed] [Google Scholar]
- Waizenhofer RN, Buchanan CM, Jackson-Newsom J. Mothers' and fathers' knowledge of adolescents' daily activities: Its sources and its links with adolescent adjustment. Journal of Family Psychology. 2004;18:348–360. doi: 10.1037/0893-3200.18.2.348. [DOI] [PubMed] [Google Scholar]
- Wittchen HU, Frohlich C, Behrendt S, Gunther A, Rehm J, Zimmermann P, et al. Cannabis use and cannabis use disorders and their relationship to mental disorders: A 10-year prospective-longitudinal community study in adolescents. Drug and Alcohol Dependence. 2007;88:S60–S70. doi: 10.1016/j.drugalcdep.2006.12.013. [DOI] [PubMed] [Google Scholar]