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Adolescent marijuana use is an issue of concern to the community at large. Physicians now have the technology to identify marijuana use and thus are in a unique position to deal with the issue. This article addresses the moral issues related to screening and surveillance of adolescent marijuana use and postulates the justification for active physician intervention.
This study investigated possible explanations for increases in marijuana use among eighth grade students in Texas from 1992 to 1996. The variables examined were availability of marijuana, perceived dangerousness of marijuana use, use of alcohol and cigarettes, parental attitudes toward marijuana use, and a number of other variables related to family, peers, and school. Although many of these variables were strongly related to marijuana use during the past year, only measures relating to availability of marijuana showed increases in prevalence similar to those of marijuana use across three time periods investigated. Another finding of interest was the dramatic increase (from 4% in 1992 to 24% in 1996) in marijuana use among African American students.
This paper reports the prediction of marijuana use cessation among young adults who were regular users 5 years earlier. Social, attitude, intrapersonal, violence-related, drug use, and demographic baseline measures served as predictors of whether or not 339 teenage marijuana users reported having quit use 5 years later. Young adult social role variables were included as additional predictors. Quitting was defined as having not used marijuana in the last 30 days (42% of the sample at follow-up). After controlling for covariation among predictors, in a three-step analysis, only baseline level of marijuana use, male gender, young adult marital status, and friends' marijuana use (marginal) remained statistically direct predictors. Implications of these results include the need to reduce psychological dependence on marijuana and increase social unacceptability of marijuana use across genders to help increase prevalence of quit attempts.
BACKGROUND: Results of previous research examining long-term residual effects of marijuana use on cognition are conflicting. A major methodological limitation of prior studies is the inability to determine whether differences between users and non-users are due to differences in genetic vulnerability preceding drug use or due to the effects of the drug. METHOD: Fifty-four monozygotic male twin pairs, discordant for regular marijuana use in which neither twin used any other illicit drug regularly, were recruited from the Vietnam Era Twin Registry. A minimum of 1 year had passed since the marijuana-using twins had last used the drug, and a mean of almost 20 years had passed since the last time marijuana had been used regularly. Twins were administered a comprehensive neuropsychological test battery to assess general intelligence, executive functioning, attention, memory and motor skills. Differences in performance between marijuana-using twins and their non-using co-twins were compared using a multivariate analysis of specific cognitive domains and univariate analyses of individual test scores. Dose response relationships were explored within the marijuana-using group. RESULTS: Marijuana-using twins significantly differed from their non-using co-twins on the general intelligence domain; however, within that domain only the performance of the block design subtest of the Wechsler Adult Intelligence Scale--Revised reached a level of statistical significance. CONCLUSIONS: Out of the numerous measures that were administered, only one significant difference was noted between marijuana-using twins and their non-using co-twins on cognitive functioning. The results indicate an absence of marked long-term residual effects of marijuana use on cognitive abilities.
This study compared the concordance of self-report for recent marijuana use with results obtained from urine drug screen. The sample consisted of adolescent sons of fathers with DSM-III-R lifetime substance use disorder (SUD) [high average risk (HAR); N= 75] and sons of fathers with no Axis 1 psychiatric or SUD [low average risk (LAR); N= 125]. To avoid recall bias, and to ensure that the timeframe for accurate detection was restricted to promote accuracy, urine drug screen results were compared to self-reported marijuana use during the prior 48 h using an interview format. The HAR group of adolescents reported a higher rate of recent cannabis use and also had a higher rate of cannabis detection as measured in urine. The two groups did not differ with respect to either over or under-reporting marijuana use. Overall, of 19 participants who obtained positive urine cannabis results, six (31.5%) verbally denied that they used marijuana within the previous 2 days. Among the 181 participants who obtained a negative urine drug screen, 20 subjects (11.5%) inaccurately asserted that they had used marijuana within the prior 2 days. In total, 13% of the participants (26/200) inaccurately reported recent cannabis use. These results underscore the need for caution in interpreting the results of self-report methods documenting the prevalence of drug use among youth.
The present study uses data from a meta-analytic archive of prospective longitudinal studies (N= 3206) to examine the association between negative affect, emotionality, and unconventionality on the use, misuse, and abuse of marijuana. For each of the three constructs, variables were divided into two categories--a "trait," which refers to a personality characteristic or attitudes and beliefs, and a "behavior," which refers to something that a subject does. A total of 63 reports from 40 studies provided effect sizes on the bivariate relationship of one or more of these six categories with current or later marijuana use, misuse, or abuse. Pooling partially redundant estimates for independence reduced the dataset from 358 estimates to 93 aggregated effect sizes for the cross-sectional data included in the archive, and from 478 estimates to 73 aggregated effect sizes for the longitudinal data. The effect sizes obtained from the longitudinal data were modest, none above 0.20. Indeed, only those for unconventionality-trait and emotionality-trait and marijuana use were of sufficient magnitude and reliably to warrant attention. Of the behavioral constructs assessed using the cross-sectional data, only unconventionality was associated with marijuana use and misuse. The emotionality-behavior construct and both unconventionality constructs were most strongly associated with marijuana abuse. The conceptual and methodological limitations of the study along with the implications of its findings for prevention are briefly discussed.
Our study sought to determine the incidence of weekly marijuana use among HIV-infected and uninfected women, to identify correlates of weekly marijuana use, and to test its association with stage of HIV disease and type of HIV treatment received. A total of 2059 HIV-positive and 569 HIV-negative women from 6 sites were recruited between 1994 and 1995 and followed through 2000. After excluding women who reported weekly marijuana use at baseline, 2050 women were included in the analysis. The incidence rate for initiating marijuana was calculated and survival analysis was performed to determine the correlates of initiating weekly marijuana use. Three hundred and three women initiated weekly marijuana use within 5.5 years of the baseline visit, yielding a cumulative incidence (CI) of 14.8%. There was no significant difference in weekly marijuana use initiation between HIV-infected (CI = 14.5%) and HIV-uninfected women (CI = 16.0%). Younger age and having more sex partners was associated with incident weekly marijuana use among both infected and uninfected women. While undetectable viral load was associated with lower incidence rate (p < 0.001, RH = 0.44) and wasting syndrome with higher incidence (p < 0.01, relative hazard [RH] = 3.1), CD4 count was not. Compared to receiving no AIDS treatment at all, women who received basic combination antiretroviral therapy had significantly higher incidence of weekly marijuana use (p < 0.001, RH = 1.93), while highly active antiretroviral therapy (HAART) receivers had significantly lower incidence (p < 0.001, RH = 0.24). In summary, among HIV-infected women, the incidence of weekly marijuana use was associated with only one marker of HIV disease stage and HAART was associated with lower initiation rate of weekly marijuana use.
The purpose of this study was to determine if a modified version of the Contemplation Ladder, a measure of motivation to change marijuana use among incarcerated adolescents (Marijuana Ladder; ML), was related to marijuana use and treatment engagement. Participants (N=122) in this study were all incarcerated at a state juvenile correctional facility in the Northeast. Adolescents were assessed at the beginning of their incarceration, 2 months into their incarceration, and 3 months after their release. There was a significant negative relationship between ML scores and marijuana use and a significant positive relationship between ML scores and treatment engagement. When controlling for prior marijuana use and age, ML scores at baseline significantly added to the prediction of marijuana use and treatment engagement among incarcerated adolescents. Results support the concurrent validity and the predictive validity of the ML. This measure has the potential to provide important information for Juvenile Justice Facilities that might aid in treatment planning and discharge planning for incarcerated adolescents. In addition, researchers may find a quick visual analog measure of motivation to change marijuana use with good psychometric properties useful.
AIMS: To examine changes in marijuana use in a metropolitan region and a provincial/rural region in New Zealand between 1990 and 1998. METHODS: Two random sample surveys of people aged 15 -45 years were carried out in Auckland and Bay of Plenty regions in 1990 and 1998, using a computer-assisted telephone interviewing system. RESULTS: Use of marijuana in the last twelve months increased in the metropolitan sample from 18% to 22%, but not in the provincial area. Those who had ever tried marijuana increased from 43% of the total sample in 1990 to 52% in 1998. Use was higher among men than women, but had increased among women. There was a trend towards more frequent users of marijuana (ten or more occasions in the previous 30 days), from 2.4% to 3.2%. CONCLUSIONS: Experience of marijuana was slightly more common in 1998 than in 1990, but increases in recent use were small and were found only in the metropolitan area. The increase in use was relatively limited: only one in five of each sample had used marijuana in the past year, and opportunity to use marijuana by non-users had not increased. Use was predominantly casual and social, and most who had tried marijuana no longer used the drug. However, the age at which first use occurred appeared to have declined.
This longitudinal study is an examination of the relationship between marijuana use and the assumption of adult roles, as well as the relationship between assuming adult roles and the likelihood of later marijuana use. Data were collected at 5 points in time from childhood through early adulthood (late 20s) by means of a structured questionnaire. Participants' marijuana use and the assumption of adult roles, including employment, marriage, parenthood, and living arrangements, were measured, and the data were analyzed with logistic regression analyses. A history of marijuana use was associated with an increased risk of adopting more unconventional adult roles, such as postponement of marriage, having a child out of wedlock, and unemployment. These results suggest that frequent prior marijuana use may adversely affect one's ability to successfully assume conventional adult roles. Furthermore, controlling for earlier marijuana use, marriage during early adulthood significantly decreased the risk of later marijuana use.
Marijuana is one of the most widely used recreational substances in the world, considered by many consumers as a relatively safe drug with few significant side-effects. We report the case of a 21-year-old man who suffered an acute myocardial infarction following the use of marijuana, despite having no other identifiable risk factors for an acute cardiovascular event. We review the published medical literature regarding acute cardiovascular events following marijuana use and postulate a possible mechanism for this unusual pathological consequence of marijuana use.
OBJECTIVES: To identify general and differentiating risk and protective factors from domains of culture and ecology, peer, family, and personality, related to adolescent delinquency and marijuana use, and to study the protective role of the parent-child mutual attachment in offsetting cultural and ecological risk factors, leading to less delinquency and marijuana use. DESIGN: Cross-sectional analyses of interview data collected in Colombia. PARTICIPANTS: A total of 2837 Colombian adolescents, 12 to 17 years of age. SETTING: Adolescents were interviewed in their homes. MAIN MEASURES: Independent variables included measures from 4 domains: culture and ecology, peer, family, and personality. The dependent variables were delinquency and marijuana use. RESULTS: Several risk factors, such as tolerance of deviance and sensation seeking, were similarly related to both delinquency and marijuana use, suggesting that a common cause underlies the propensity to engage in different deviant behaviors. Some risk factors were more involved in delinquency and other risk factors were more highly related to the adolescent's marijuana use. Finally, when violence is endemic and illegal drugs are readily available, a close parent-child bond was capable of mitigating these risk factors, leading to less marijuana use and delinquency. CONCLUSIONS: The findings have implications for public health policy related to interventions in countries in which violence and drug use are prevalent. The results point to interventional procedures aimed at adolescents vulnerable to marijuana use and delinquency as well as efforts aimed at specific vulnerabilities in these areas. For example, reducing the risk factors and enhancing the protective factors for marijuana use and delinquency may result in less adolescent marijuana use and delinquency.
A questionnaire investigating adolescents' opinions and experiences regarding marijuana use was administered to 163 adolescents and young adults (96 boys and 67 girls) aged 13 to 20 (mean age = 16.8, s.d. = 1.5). Items referred to marijuana and other substances' dangerousness, representations regarding the positive and negative consequences of marijuana use. Responses were compared according to marijuana use status (classified into never/occasional use, current regular use and past regular use). Results show that adolescents' opinions differ according to their experience with marijuana use. Current regular users evaluate marijuana as less dangerous, but alcohol and heroin as more dangerous in comparison with never/occasional and past users. Current and past users are more likely to define marijuana as a medical drug and a plant used in agriculture, and less likely to define it as an illegal drug. Current and past users evaluate marijuana use as a way to cope with stress, to relax to a greater extent than do never/occasional users do. The latter attribute more negative consequences to marijuana use such as diminished driving ability and school performance and a pathway to hard drugs.
A sample of 1,270 students in Years 7, 10 and 11 attending seven State high schools in a middle class area of Sydney answered a self-report questionnaire designed to measure many aspects of their family situation, school performance, spare time activities, drinking and drug taking behaviour and sexual activity. Data on the reported prevalence of marijuana use and the variables significantly associated with marijuana use are presented and discussed. Marijuana use was reported by 4.2% of 12 year olds (Year 7), 26.5% of 15 year olds (Year 10) and 26.7% of 16 year olds (Year 11). More than half of those who had ever used marijuana had used it during the week prior to the survey and there were no significant differences in the characteristics between these recent and the remaining users. Marijuana users reported significantly poorer family relationships than non-users and were about twice as likely as non-users to come from a broken home and/or to have a mother who works full-time, which is often a consequence of marital break-up. Marijuana users also displayed poorer school performance, spent less time on homework and had more school absenteeism than non-users. Marijuana users were more than three times as likely as non-users to have had heterosexual intercourse, drunk alcohol 3 or more times in the past week and to smoke cigarettes. Also, the reported use of stimulants, hallucinogens, narcotics (heroin) and sedatives was almost entirely restricted to those who reported marijuana use. Improvements in the quality of family life may prevent the use of marijuana and other probably more harmful drugs, as well as the indulgence in other acting-out behaviours.
Attitude toward drug-free experience is conceptualized as a psychological context for drug use that influences the evaluation of perceived consequences of marijuana use. Two studies examined the moderating effect of attitude toward drug-free experience on relationships between attitudes toward marijuana and drug use. In Study 1 (N = 316), attitude toward drug-free experience emerged as a significant moderator. Participants with positive attitudes toward marijuana use and relatively low attitudes toward drug-free experience used marijuana at the highest rates. Study 2 (N = 308) provided a partial replication and extension. In a second sample, a quadratic relationship emerged between drug-free experience and marijuana use. The interaction between the two attitudes approached significance. Among the 47 participants who had used marijuana more than 100 times in their lifetime, attitude toward drug-free experience moderated the relationship between attitude toward marijuana and marijuana-related problems.
Event history analysis was applied to monthly life and drug histories of a representative community sample of 706 marijuana users, followed from ages 15-16 to 34-35, to investigate factors associated with cessation of marijuana use from adolescence to adulthood. In addition to age and gender, the most important determinants of cessation are the phenomenology of marijuana use, social role participation, depressive symptoms and deviance. Frequent users, those who started using early and those who use illicit drugs other than marijuana are more likely to continue their marijuana use. Using marijuana for social reasons accelerates cessation, using to change one's mood reduces cessation. Becoming pregnant and a parent is the most important social role leading to marijuana cessation for women. There is also a very important experimental effect of the interview itself on the reported timing of a cessation. The effect of a social context favorable to marijuana use appears to reflect selection rather than social influence.
Information on drug-related behaviors was obtained from a random sample of teenagers aged 14 to 19 years in Sydney, Australia, interviewed in their homes in 1985 (N = 996) and 1986 (N = 756). The 1985 prevalence of current marijuana use was 10%. The predictors of marijuana use were: male sex; heavier, more frequent alcohol use; use of drugs other than alcohol, tobacco, or marijuana; marijuana use by siblings, friends, and other acquaintances; attitudes and beliefs favoring drug use; the attitude that possession of marijuana should not be a criminal offense; and the attitude that marijuana is not an important drug issue. In the 756 reinterviewed respondents, prevalence of marijuana use rose from 7% in 1985 to 9% in 1986. The rate of uptake was 6% and peaked at 12% at age 17. The predictors of uptake were: age; male sex; heavier, more frequent alcohol use; tobacco smoking; attitudes and beliefs favoring drugs use; and the attitude that marijuana smoking should be legal. Strategies to prevent marijuana use need to take into account the strong association between heavy drinking and marijuana use, the influence of drug users in the social network, and attitudes and beliefs about drugs.
Relationships between age at initial marijuana use and selected behavioral measures representing education, arrests, employment, alcohol use, and other drug use were examined for a sample of 370 male veterans. Younger age at marijuana use was found to be associated with less education, more arrests, and more other drug use prior to entering the service. A factor analysis of the correlates of age at initial marijiana use suggested three factors of delinquent activities: drug use, school delinquency, and other propensities for delinquency.