Trends in use of marijuana and attitudes toward marijuana among youth before and after decriminalization: the case of California 2007-2013

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.

The "Jay-Dar" Phenomenon: Individuals Discriminate Cannabis Users from Nonusers Based Upon a Photograph

OBJECTIVE

With increasing legalization of medicinal and recreational cannabis, use is on the rise. Research suggests individuals may be able to guess cannabis user status based upon appearance; however, these findings utilized a small sample of photographs that was not balanced on user status or gender. Further, no studies examined whether raters with cannabis experience are better at judging others' cannabis use, or what physical features they use to make these judgments. This study explored these factors using a larger, balanced photograph database.

METHOD

An American sample (n = 249, 48.6% female, mean age = 35.19 years) rated 36 photographs (18 cannabis users, 18 nonusers) balanced on gender and age on the likelihood that the photographed individuals use cannabis, producing 8964 ratings. Respondents also reported physical features considered in their ratings, as well as their own cannabis use history.

RESULTS

As hypothesized, photographs of users received higher ratings on the Marijuana Use Likelihood Index relative to nonusers. Further, results revealed a gender by rater user status interaction, indicating that raters with no previous cannabis experience rated males higher than females, while raters with cannabis experience did not demonstrate this rating discrepancy. Cannabis use explained over 9% of the variance in ratings across all photographs.

CONCLUSIONS

Results suggest individuals do rate cannabis users as more likely to be users, relative to nonusers, based upon appearance alone. These findings have important implications, not only for research on chronic cannabis use effects, but also for social and achievement factors such as potential stigma.

The Impact of Recreational Marijuana Legislation in Washington, DC on Marijuana Use Cognitions

BACKGROUND

There is little published research that tests the effect of recreational marijuana legislation on risk-related cognitions and how individuals respond immediately after legislative approval.

OBJECTIVES

The objective was to test whether learning about the passage of Initiative 71, a voter referendum that legalized recreational use of marijuana in the District of Columbia, would lead individuals to adopt more favorable marijuana cognitions than they had before the Initiative was passed.

METHODS

Undergraduate students (N = 402) completed two web-based questionnaires in 2014. The first questionnaire was completed prior to the referendum vote and the follow-up questionnaire was completed after voters approved Initiative 71. Attitudes, perceived norms, intentions, prototypes, and willingness were measured at time 1 and time 2. Study hypotheses were tested using repeated-measures analysis of covariance.

RESULTS

Results showed that attitudes, intentions, perceived norms, and willingness to use marijuana were more favorable after Initiative 71 was passed. However, the increase in attitudes and willingness was moderated by past experience with marijuana whereby the increases were statistically significant only among those with the least experience. The increase in perceived norms was also moderated by past experience whereby increases were statistically significant among those who were moderate or heavy users. The passage of Initiative 71 had no effect on favorable prototypes. Conclusion/Importance: Legalization may have the unintended outcome of leading to more favorable intentions to use marijuana and might lead abstainers or experimental users to become more frequent users of marijuana via more positive attitudes and willingness towards marijuana use.

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

BACKGROUND

The overall prevalence of U.S. young adult alcohol use has decreased, but little is known about historical change in related behaviors such as simultaneous alcohol and marijuana (SAM) use that may increase alcohol-related risks and societal costs. The purpose of this paper was to examine historical change in SAM use prevalence among U.S. young adult alcohol users from 1977 to 2016, and consider the extent to which observed historical change in SAM use among alcohol users reflects co-occurring change in marijuana use during these years.

METHODS

Data on past 12-month alcohol, marijuana, and SAM use at up to 6 modal ages (19/20, 21/22, 23/24, 25/26, 27/28, and 29/30) were collected from 11,789 individuals (45.0% men) participating in the Monitoring the Future panel study. Annual prevalence estimates within modal age group were obtained; historical SAM use trends among alcohol and marijuana users were estimated.

RESULTS

From 2014 to 2016, SAM use was reported by approximately 30% of alcohol users aged 19/20 and 21/22, and 20 to 25% of alcohol users aged 23/24 through 29/30. Since the mid-1990s, age-specific historical trends in SAM use prevalence among alcohol users followed 1 of 4 patterns: significant increase followed by oscillating increases/decreases (at modal age 19/20), consistent and significant increases (at modal ages 21/22, 23/24, and 25/26), stability followed by increase (at modal ages 27/28), or stability (at modal ages 29/30). In contrast, SAM use trends among marijuana users primarily reflected stability, with some evidence of a decrease across time at modal ages 19/20 and 23/24. Historical change in SAM prevalence among alcohol users was strongly and positively correlated with changes in overall marijuana use prevalence.

CONCLUSIONS

A growing proportion of early and mid-young adult alcohol users reported SAM use, with the highest risk among those in the early years of young adulthood. Young adult SAM use may continue to increase in proportion to the degree that young adult marijuana use continues to increase.

Cannabis decriminalization: A study of recent policy change in five U.S. states

BACKGROUND

A number of public health professional organizations support the decriminalization of cannabis due to adverse effects of cannabis-related arrests and legal consequences, particularly on youth. We sought to examine the associations between cannabis decriminalization and both arrests and youth cannabis use in five states that passed decriminalization measures between the years 2008 and 2014: Massachusetts (decriminalized in 2008), Connecticut (2011), Rhode Island (2013), Vermont (2013), and Maryland (2014).

METHODS

Data on cannabis possession arrests were obtained from federal crime statistics; data on cannabis use were obtained from state Youth Risk Behavior Survey (YRBS) surveys, years 2007-2015. Using a "difference in difference" regression framework, we contrasted trends in decriminalization states with those from states that did not adopt major policy changes during the observation period.

RESULTS

Decriminalization was associated with a 75% reduction in the rate of drug-related arrests for youth (95% CI: 44%, 89%) with similar effects observed for adult arrests. Decriminalization was not associated with any increase in the past-30 day prevalence of cannabis use overall (relative change=-0.2%; 95% CI: -4.5%, 4.3%) or in any of the individual decriminalization states.

CONCLUSIONS

Decriminalization of cannabis in Massachusetts, Connecticut, Rhode Island, Vermont, and Maryland resulted in large decreases in cannabis possession arrests for both youth and adults, suggesting that the policy change had its intended consequence. Our analysis did not find any increase in the prevalence of youth cannabis use during the observation period.

On the use of digital technologies to reduce the public health impacts of cannabis legalization in Canada

The imminent legalization of recreational cannabis represents a considerable public health challenge that requires proactive measures to ensure a responsible transition. The federal government recognizes the need for strict regulation to reduce cannabis-related health harms, notably among the youth. Additionally, the government plans to oversee a national public awareness campaign as part of a harm-reduction strategy. In light of the public health risks of cannabis legalization, this paper proposes the implementation of increasingly popular, evidence-based, preventive, and therapeutic digital interventions to minimize the harms of this policy among adolescents and young adults. These E-health interventions facilitate healthcare delivery, improve patient care, and overcome stigmatization, especially in the context of substance abuse. Therefore, we argue that a continuum of digital tools, including prevention programs, educational material, and therapeutic interventions aimed at reducing risky consumption of cannabis, should be embraced as part of a comprehensive public health strategy by the federal government in anticipation of legalization later this year.

Is Cannabis Use Associated with Various Indices of Motivation among Adolescents?

Decreased motivation is often noted as a consequence of cannabis use (CU). Previous work has yielded mixed findings, relied mostly on adult samples, and varied to the extent that it accounted for potential confounds. This study examines associations between CU and several motivation indices among adolescents. We hypothesized that regular cannabis users would report lower motivation than light users, and that greater lifetime and past 30-day CU amounts would be associated with decreased motivation. Participants were 79 adolescents, ages 14-18, classified as recent regular cannabis users (n = 36) or light users (n = 43). Frequency and amount of substance use were assessed across participants' lifetime and during the past 30 days. Motivation was measured through the Apathy Evaluation Scale and Motivation and Engagement Scale. To examine associations between CU and our motivation indices, we conducted a series of two-step hierarchical multiple regressions. Variables found to correlate with any motivation measure were entered on step 1 (e.g., mental health, other substance use) and the relevant CU variable was entered on step 2. After controlling for confounds, no significant differences were observed between regular and light users on any motivation index, p > .01. Similarly, no associations between motivation and lifetime or past 30-day CU amount were observed, p > .01. Our findings do not support a link between reduced motivation and CU among adolescents after controlling for relevant confounds. Future studies will examine the levels of CU which influence motivation in adolescents, and the conditions under which this link becomes manifest.

Media/Marketing Influences on Adolescent and Young Adult Substance Abuse

PURPOSE OF REVIEW

We describe the state of research on substance use portrayals in marketing and media, considering exposure to tobacco, alcohol, e-cigarette, and marijuana content. Putative mechanisms are offered, and recommendations made for effective prevention strategies for mitigating the influence of these portrayals.

RECENT FINDINGS

There is consistent evidence that adolescents and young adults are highly exposed to substance use portrayals and that these portrayals are associated with subsequent substance use. Exposure via new media (social networking sites, brand websites) has risen rapidly. Social norms and cognitions appear to at least partially account for the effects of portrayals on youth substance use.

SUMMARY

Digital media has surpassed traditional marketing, which is concerning because youth have on-demand access to content and are active consumers of digital media. Developmentally appropriate media literacy interventions that include a parenting component and target multiple substances and media domains are recommended.

Media/Marketing Influences on Adolescent and Young Adult Substance Abuse

PURPOSE OF REVIEW

We describe the state of research on substance use portrayals in marketing and media, considering exposure to tobacco, alcohol, e-cigarette, and marijuana content. Putative mechanisms are offered, and recommendations made for effective prevention strategies for mitigating the influence of these portrayals.

RECENT FINDINGS

There is consistent evidence that adolescents and young adults are highly exposed to substance use portrayals and that these portrayals are associated with subsequent substance use. Exposure via new media (social networking sites, brand websites) has risen rapidly. Social norms and cognitions appear to at least partially account for the effects of portrayals on youth substance use.

SUMMARY

Digital media has surpassed traditional marketing, which is concerning because youth have on-demand access to content and are active consumers of digital media. Developmentally appropriate media literacy interventions that include a parenting component and target multiple substances and media domains are recommended.

Medical Marijuana and Marijuana Legalization

State-level marijuana liberalization policies have been evolving for the past five decades, and yet the overall scientific evidence of the impact of these policies is widely believed to be inconclusive. In this review we summarize some of the key limitations of the studies evaluating the effects of decriminalization and medical marijuana laws on marijuana use, highlighting their inconsistencies in terms of the heterogeneity of policies, the timing of the evaluations, and the measures of use being considered. We suggest that the heterogeneity in the responsiveness of different populations to particular laws is important for interpreting the mixed findings from the literature, and we highlight the limitations of the existing literature in providing clear insights into the probable effects of marijuana legalization.

Dynamic transitions between marijuana use and cigarette smoking among US adolescents and emerging adults

BACKGROUND

Marijuana and tobacco are considered two closely related substances. It is of great significance to understand the mutual impact of marijuana and cigarette use when more states in the US have legalized marijuana use.

OBJECTIVE

This study aims to investigate the transitions between marijuana and cigarette use among adolescents and emerging adults.

METHOD

Guided by the probabilistic discrete events systems (PDES) theory, a five-stage model with 21 transition paths was constructed to quantify dynamic transitions between marijuana and cigarette use. The five stages were NU: Never-user, MU: Current marijuana user, CU: Current cigarette user, MCU: Current marijuana-cigarette user, and FU: Former-user. The proposed five-stage PDES model was tested using the 2013 National Survey on Drug Use and Health data (N = 26,665, 50.45% male). Transition probabilities were estimated using the Moore-Penrose generalized inverse matrix method.

RESULT

Among the adolescents, 51.14% of the CUs transited to use marijuana (MCU/MU), higher than the proportion of those who first used marijuana and then transferred to cigarettes (MCU/CU) (41.66%). The quitting rates for MUs, CUs and MCUs were 29.38%, 25.93% and 27.76%, respectively. Of the total FUs, 31.90% transited to MUs, 17.06% to CUs, and 17.39% to MCUs. Among the young adults, more people progressed from MUs to CUs. Transition probabilities by single year of age were also estimated.

CONCLUSION

This is the first study to quantify marijuana-cigarette transitions. Study findings indicate more cigarette-to-marijuana transitions for adolescents and more marijuana-to-cigarette transitions for emerging adults. Future intervention programs should consider this age-related difference in marijuana-cigarette use transitions.

Medical Marijuana Laws and Marijuana Use Among U.S. Adolescents: Evidence From Michigan Youth Risk Behavior Surveillance Data

Research findings are inconsistent regarding a positive association between the passage of state medical marijuana laws (MML) and adolescent access and use marijuana. We utilized a novel analytical approach to examine this issue with multi-year data from the 1997–2013 Youth Risk Behavior Surveillance System (YRBSS) of the State of Michigan. After controlling for the historically declining trend in marijuana use prior to the passages of MML in Michigan, we found that marijuana use among adolescents had increased subsequent to the passage of state MML. Study findings suggest the need for considering the increased risk of marijuana use among adolescents as the number of states with laws permitting marijuana use is increasing.

The relationship between family-based adverse childhood experiences and substance use behaviors among a diverse sample of college students

INTRODUCTION

Research suggests that college students are an especially vulnerable subset of the population for substance use and misuse. However, despite evidence of the high prevalence of adverse childhood experiences (ACE) among students and the link between family-based ACE and substance use among older adults, this relationship remains understudied in college populations. Moreover, whether ACE represents a shared risk across substance use behaviors and ethnic groups is unknown.

METHODS

Data are student responses (n=2953) on the 2015 American College Health Association's National College Health Assessment II (ACHA-NCHA II) administered at one of the largest, most diverse public universities in California. Multivariable logistic and negative binomial regression models tested the association between individual and accumulated ACE and past 30-day alcohol, tobacco, marijuana, and illicit drug use, past 12-month prescription medication misuse and polysubstance use.

RESULTS

Between 50% and 75% of students involved in substance use were ACE exposed. There was a significant dose-response relationship between ACE and substance use and polysubstance use. Although accumulated ACE increased risk for substance use, there was considerable ethnic variability in these associations.

CONCLUSIONS

The graded effects of ACE for substance use underscore the link between family-based stressors and these behaviors in emergent adult college students. Our findings make a compelling case for investing in health initiatives that prioritize ACE screening and access to trauma-informed care in campus communities. Continued research with college populations is needed to replicate findings and clarify the role of ethnicity and culture in trauma response and help seeking behaviors.

Longitudinal associations between marijuana-related cognitions and marijuana use in African-American and European-American girls from early to late adolescence

This study examined marijuana-related cognitions and marijuana use in African-American (AA) and European-American (EA) girls, with the aim of characterizing their interrelationships from early to late adolescence. Identifying differences by race in these relationships would have implications for tailoring interventions to specific subgroups. Data were drawn from the Pittsburgh Girls Study, an urban community sample (56.8% AA, 43.2% EA; n = 2,172) recruited at ages 5-8 years and assessed each year. Cross-lagged panel models were conducted separately by race to identify patterns of association between marijuana use and related cognitions (i.e., intentions to use, positive attitude toward use, positive and negative expectancies) assessed at ages 12-17 years. Results indicated that AA girls consistently reported higher negative expectancies than EA girls and greater intention to use marijuana, but they did not differ from EA girls on positive expectancies. In cross-lagged models, bidirectional effects between negative expectancies and marijuana use were observed in AA and EA girls across all ages, and at most ages for intentions to use, but were largely absent in both groups for positive attitude. Bidirectional effects of marijuana use with positive expectancies were observed only in AA girls at certain ages. Overall, results demonstrate more similarities than differences between AA and EA girls in the longitudinal associations between marijuana-related cognitions and marijuana use. Results highlight the role of negative expectancies as shaping and being shaped by marijuana use. Interventions that target negative expectancies to reduce marijuana use may be useful for AA and EA adolescent girls. (PsycINFO Database Record

The potential impact of cannabis legalization on the development of cannabis use disorders

Specific provisions of legal cannabis legislation and regulation could influence cannabis initiation, frequency and quantity of use, and progression to cannabis use disorder. This brief essay highlights scientifically based principles and risk factors that underlie substance use and addiction that can be leveraged to inform policies that might mitigate the development and consequences of cannabis use disorder. Specifically, pharmacologic, access/availability, and environmental factors are discussed in relation to their influence on substance use disorders to illustrate how regulatory provisions can differentially affect these factors and risk for addiction. Relevant knowledge from research and experience with alcohol and tobacco regulation are also considered. Research designed to inform regulatory policy and to evaluate the impact of cannabis legislation on cannabis use and problems is progressing. However, definitive findings will come slowly, and more concerted efforts and resources are needed to expedite this process. In the meantime, policymakers should take advantage of the large body of scientific literature on substance use to foster empirically-guided, common sense approaches to cannabis policy that focus on prevention of addiction.

Family Physicians' Perceived Prevalence, Safety, and Screening for Cigarettes, Marijuana, and Electronic-Nicotine Delivery Systems (ENDS) Use during Pregnancy

OBJECTIVE

Assess perceptions of prevalence, safety, and screening practices for cigarettes and secondhand smoke exposure (SHSe), marijuana (and synthetic marijuana), electronic nicotine delivery systems (ENDS; eg, e-cigarettes), nicotine-replacement therapy (NRT), and smoking-cessation medications during pregnancy, among primary care physicians (PCPs) providing obstetric care.

METHODS

A web-based, cross-sectional survey was e-mailed to 3750 US physicians (belonging to organizations within the Council of Academic Family Medicine Educational Research Alliance). Several research groups' questions were included in the survey. Only physicians who reported providing "labor and delivery" obstetric care responded to questions related to the study objectives.

RESULTS

A total of 1248 physicians (of 3750) responded (33.3%) and 417 reported providing labor and delivery obstetric care. Obstetric providers (N = 417) reported cigarette (54%), marijuana (49%), and ENDS use (24%) by "Some (6% to 25%)" pregnant women, with 37% endorsing that "Very Few (1% to 5%)" pregnant women used ENDS. Providers most often selected that very few pregnant women used NRT (45%), cessation medications (ie, bupropion or varenicline; 37%), and synthetic marijuana (23%). Significant proportions chose "Do not Know" for synthetic marijuana (58%) and ENDS (27%). Over 90% of the sample perceived that use of or exposure to cigarettes (99%), synthetic marijuana (99%), SHS (97%), marijuana (92%), or ENDS (91%) were unsafe during pregnancy, with the exception of NRT (44%). Providers most consistently screened for cigarette (85%) and marijuana use (63%), followed by SHSe in the home (48%), and ENDS (33%) and synthetic marijuana use (28%). Fewer than a quarter (18%) screened consistently for all substances and SHSe. One third (32%) reported laboratory testing for marijuana and 3% reported laboratory testing for smoking status.

CONCLUSION

This sample of PCPs providing obstetric care within academic settings perceived cigarettes, marijuana, and ENDS use to be prevalent and unsafe during pregnancy. Opportunities for increased screening during pregnancy across these substances were apparent.

Parent-adolescent relationships in Hispanic versus Caucasian families: Associations with alcohol and marijuana use onset

Parent-adolescent relationship (PAR) factors such as social support and negative interactions are associated with initiation of alcohol and marijuana use during adolescence. However, few studies have examined whether the relationship between PAR, especially the paternal role, and substance use onset varies by ethnicity. This is important given that ethnic group differences have been related to alcohol and marijuana use, cultural values and parenting. This study examines whether ethnicity moderates the prospective prediction of substance use onset by PAR factors. The sample comprised 124 adolescents who self-identified as Hispanic and 795 adolescents who self-identified as non-Hispanic Whites, and was drawn from an ongoing longitudinal survey on adolescent substance use. Discrete-time survival modeling was used to prospectively predict age at onset of substance use among participants who were substance-naïve at baseline. Interactions between ethnicity and PAR factors indicated that PAR factors had a larger influence on age of alcohol and marijuana onset for Hispanics than for Caucasians. Among Hispanics, greater social support from and greater negative interactions with the father-figure were more predictive of earlier onset of alcohol, and greater social support from the mother-figure was more predictive of later alcohol onset, compared to Caucasians. Similarly, greater negative interactions with the father-figure were more predictive of earlier onset of marijuana use among Hispanics than among Caucasians. These findings suggest the influence of PAR on alcohol and marijuana use onset may be larger for Hispanics than for Caucasians. Incorporating these parenting factors in substance use prevention programs advances public health in a culturally sensitive manner that is relevant to at-risk Hispanic adolescents.

DSM-5 cannabis use disorder, substance use and DSM-5 specific substance-use disorders: Evaluating comorbidity in a population-based sample

Cannabis use disorder (CUD) is frequently associated with concurrent substance use and/or comorbid substance use disorders (SUDs); however there is little specificity with regard to commonly abused individual drug types/classes. This study therefore aimed to provide insight into the degree of these co-occurring relationships across several specific newer and older generation illicit and prescription drugs. 36,309 adults aged 18+ from wave 3 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC-III) were assessed. Weighted cross-tabulations and multivariable logistic regression analyses were used to evaluate comorbidity between current DSM-5 CUD, substance use and DSM-5 SUD. Current DSM-5 CUD is associated with greater lifetime use of all examined drug classes, and previous 12-month use of several newer-class illicit and prescription stimulant-based substances (all p< 0.05). Current DSM-5 CUD was similarly associated with increased incidence of a range of DSM-5 SUDs and was independently associated with concurrently reporting current DSM-5; sedative (Adjusted OR= 5.1, 95%CI 2.9-9.0), cocaine (AOR= 9.3, 95%CI 5.6-15.5), stimulant (AOR= 4.3, 95%CI 2.3-7.9), club drug (AOR= 16.1, 95%CI 6.3-40.8), opioid (AOR= 4.6, 95%CI 3.0-6.8) and alcohol-use disorder (AOR= 3.0, 95%CI 2.5-3.7); but not heroin or 'other' drug use disorder (both p>0.05). High comorbidity exists between DSM-5 CUD and many specific DSM-5 SUDs. Newer-class illicit and prescription stimulant-based drug use disorders are overrepresented among those with DSM-5 CUD. These findings underscore the need for tailored treatment programs for those presenting with DSM-5 CUD, and for greater treatment specification where poly-drug use is evident.

Cannabis Use, Polysubstance Use, and Psychosis Spectrum Symptoms in a Community-Based Sample of U.S. Youth

PURPOSE

To examine how cannabis use and polysubstance use among cannabis users relate to psychosis spectrum (PS) symptoms in a large community-based sample of U.S. youth.

METHODS

Four thousand one hundred seventy-one youths (aged 14-21 years; mean = 16.90 years, SD = 1.85; 55% female) from the Philadelphia Neurodevelopmental Cohort completed assessments of substance use, PS symptoms, and confounding variables (e.g., demographics, comorbid psychopathology, and trauma exposure).

RESULTS

After adjusting for confounds, cannabis use by itself was not associated with increased odds of being classified as "psychosis spectrum." However, cannabis use in combination with tobacco or other substance use was associated with increased odds of PS classification (adjusted odds ratios [ORs] = 1.37-1.76). Follow-up symptom-level analyses revealed that cannabis use in combination with other substances was associated with subclinical positive symptoms (ORs = 1.95 and 2.24) and frequent cannabis use was associated with subclinical negative/disorganized symptoms (OR = 2.14). However, these symptom-level findings were reduced to trends after correction for multiple comparisons. Neither cannabis use nor polysubstance use was associated with threshold delusions or hallucinations.

CONCLUSIONS

After adjusting for important confounds, there was minimal evidence for associations between cannabis use by itself and PS symptoms. More compelling evidence emerged for associations between polysubstance use among cannabis users and PS symptoms. This study highlights the importance of considering polysubstance use and confounds when examining associations between cannabis use and PS symptoms. Further longitudinal research is necessary to determine whether these findings represent causal associations or shared genetic and/or environmental vulnerability for substance use and PS symptoms.

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.

Effects of Adolescent Cannabinoid Self-Administration in Rats on Addiction-Related Behaviors and Working Memory

Use of marijuana (Cannabis sativa) often begins in adolescence, and heavy adolescent marijuana use is often associated with impaired cognitive function in adulthood. However, clinical reports of long-lasting cognitive deficits, particularly in subjects who discontinue use in adulthood, are mixed. Moreover, dissociating innate differences in cognitive function from cannabis-induced deficits is challenging. Therefore, the current study sought to develop a rodent model of adolescent cannabinoid self-administration (SA), using the synthetic cannabinoid receptor agonist WIN55,212-2 (WIN), in order to assess measures of relapse/reinstatement of drug seeking and long-term effects on cognitive function assessed in a delay-match-to-sample working memory task and a spatial recognition task. Adolescent male rats readily self-administered WIN in 2-h or 6-h sessions/day, but did not demonstrate an escalation of intake with 6-h access. Rats exhibited significant cue-induced reinstatement of WIN seeking that increased with 21 days of abstinence (ie, 'incubation of craving'). Cognitive testing occurred in adulthood under drug-free conditions. Both 2-h and 6-h adolescent WIN SA groups exhibited significantly better working memory performance in adulthood relative to sucrose SA controls, and performance was associated with altered expression of proteins regulating GABAergic and glutamatergic signaling in the prefrontal cortex. Self-administered WIN did not produce either acute or chronic effects on short-term memory, but experimenter administration of WIN in adolescence, at doses previously reported in the literature, produced acute deficits in short-term memory that recovered with abstinence. Thus, SA of a rewarding cannabinoid in adolescence does not produce long-term cognitive dysfunction.

Frequent marijuana use and driving risk behaviours in Canadian youth

Background

A better understanding of the relations between patterns of marijuana use and driving risks in young adulthood is needed.

Methods

Secondary analyses of self-report data from the Victoria Healthy Youth Survey. Youth (baseline ages 12 to 18; N=662; 52% females) were interviewed biannually (on six occasions) from 2003 to 2013 and classified as abstainers (i.e., used no marijuana in past 12 months), occasional users (i.e., used at most once per week), and frequent users (i.e., used more than once a week).

Results

In the frequent user group, 80% of males and 75% of females reported 'being in a car driven by driver (including themselves) using marijuana or other drugs in the last 30 days', 64% of males and 33% of females reported that they were 'intoxicated' with marijuana while operating a vehicle and 50% of males and 42% of females reported being in a car driven by a driver using alcohol. In addition, 28% of occasional users and also a small proportion of abstainers reported 'being in a car driven by a driver using marijuana or other drugs in the last 30 days'.

Interpretation

The high frequency of driving risk behaviours, particularly for frequent users, suggest that plans for legalization of recreational use should anticipate the costs of preventive education efforts that present an accurate picture of potential risks for driving. Youth also need to understand risks for dependence, and screening for and treatment of marijuana use disorders is needed.

Associations Among Excess Weight Status and Tobacco, Alcohol, and Illicit Drug Use in a Large National Sample of Early Adolescent Youth

Adolescent substance use and overweight/obesity each are public health priorities, with unique prevalences based on race/ethnicity. Whether these biobehavioral risks are linked in today's youth is unknown, leaving critical gaps in prevention science. Utilizing a national epidemiological sample of 10th grade students (N = 19,678; M age = 16.09 years; 69.5 % White, 14.5 % Black, 16.0 % Hispanic; 2008-2009 Monitoring the Future), we examined adolescent substance use behaviors (current use, grade of first use, polysubstance use) for adolescents of overweight (OV), obese (OB), or severely obese (SO) status compared to adolescents of healthy weight (HW) for each race/ethnicity group. We also examined how engagement in smoking behaviors (current, early grade at first use) was linked to other substance use behaviors for youth of varying degrees of excess weight. Relative to HW youth, White youth of excess weight, particularly SO, had higher odds of early (< grade 9) substance use and use of some illicit substances (inhalants, cocaine, amphetamines) within the past year. Among White early smokers, OB and SO had higher odds of other substance use, whereas White OB and SO recent smokers had lower odds of other substance use. Few significant findings based on weight status were identified for Black or Hispanic youth. These findings suggest adolescent health risk behaviors co-occur uniquely for White youth, in particular those who are SO and by early adolescence. Understanding the downstream public health consequences and how risk pathways of excess weight, tobacco, and other substance use may uniquely unfold for each race/ethnicity group is imperative.

Quality of life and recreational cannabis use

INTRODUCTION

Cannabis is now the most commonly used illicit drug in the United States and use is increasing. Frequent cannabis use has been associated with adverse social and health effects. We sought to evaluate the relationship between recreational cannabis use and Quality of Life (QoL), a person-centered measure that characterizes the overall sense of health and wellbeing. We hypothesized that QoL would be unchanged or increased among recreational cannabis users, who did not meet criteria for a Cannabis Use Disorder (CUD) and that QoL would be lower among those who met criteria for a CUD.

METHODS

We conducted a systematic review, employing guidelines from Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The results were categorized into tables and identified trends.

RESULTS

Fourteen studies met our pre-defined selection criteria. The studies were heterogeneous and their quality was low. With one exception, we did not identify any population for whom cannabis use was associated with improved QoL. QoL was lower in persons who used cannabis heavily, or who met criteria for CUD. However, this association was inconsistent and the magnitude was weaker than the relationship between QoL and use of other addictive substances (including tobacco and illicit drugs).

CONCLUSION

In this systematic review, heavy cannabis use or CUD was associated with reduced QoL. It is unknown whether reduced QoL drives cannabis use, or whether cannabis use can lead to reduced QoL. Prospective studies are needed to evaluate the causal relationship between cannabis and QoL.

SCIENTIFIC SIGNIFICANCE

Furthering the understanding of the relationship between cannabis and QoL can inform public policy, prevention efforts, outcomes, and an objective understanding of the effects of cannabis users. (Am J Addict 2017;26:8-25).

State and National Contexts in Evaluating Cannabis Laws: A Case Study of Washington State

As of January 2016, 23 U.S. states and the District of Columbia have legalized medical or nonmedical cannabis, with more likely to follow. This dynamic policy context represents a substantial challenge for policy evaluation. Part I of this article provides a summary of state-level cannabis policy components across states and federal action regarding state-level policies. Part II presents a detailed history of cannabis policies in Washington State from 1998 to 2015 and analyzes the potential impacts of the policy changes on cannabis supply and demand. As an early adopter of both medical and nonmedical cannabis policies, Washington State provides an excellent example of the key elements to be considered in evaluating the relationship between policy changes and cannabis use. We highlight the importance of the interplay of federal enforcement priorities and previously adopted state-level cannabis regimes in interpreting the potential impacts of new cannabis policies.

What Do We Know Now About the Impact of the Laws Related to Marijuana?

OBJECTIVES

This study presents information on the status and impact of medical and legalized marijuana, and the latest data on attitudes and prevalence of use since implementation of these laws. Recent reports from epidemiologists in Denver and Seattle are summarized to give the readers a sense of the changes as these laws have taken effect in their communities.

METHODS

The status of these laws is reviewed and the results of surveys taken before and after the laws were enacted are presented, along with data on changing potency and driving under the influence of marijuana.

SUMMARY

Prevalence of use by youths has not increased, but their negative attitudes towards the risk of using marijuana have decreased, and use by adults has increased. Potency continues to increase, as has the proportion of drivers testing positive for use of the drug. Data from Denver show increases in hospital admissions, emergency department visits, and calls to poison centers, with decreasing arrests and admissions to substance abuse treatment programs. Data from the Seattle area show similar decreases in treatment admissions and police involvement, but also increased prevalence of more frequent use.

CONCLUSIONS

Current data suggest that increases in marijuana use preceded legalization in 2012. Treatment admissions were declining before these laws, but some indicators of morbidity seem to be increasing subsequent to legalization, with modest increases in poison center calls in both states and increases in acute medical visits in Denver. Data are needed to understand the relationship between the patterns and amounts of use in terms of consequences, and data on the health conditions of those receiving medical marijuana and the impact of higher potency.

Considering marijuana legalization carefully: insights for other jurisdictions from analysis for Vermont

BACKGROUND AND AIMS

In 2014 the legislature of Vermont, USA passed a law requiring the Secretary of Administration to report on the consequences of legalizing marijuana. The RAND Corporation was commissioned to write that report. This paper summarizes insights from that analysis that are germane to other jurisdictions.

METHOD

Translation of key findings from the RAND Corporation report to the broader policy debate.

RESULTS

Marijuana legalization encompasses a wide range of possible regimes, distinguished along at least four dimensions: which organizations are allowed to produce and supply the drug, the regulations under which they operate, the nature of the products that can be distributed and taxes and prices. Vermont's decriminalization had already cut its costs of enforcing marijuana prohibition against adults to about $1 per resident per year. That is probably less than the cost of regulating a legal market. Revenues from taxing residents' purchases after legalization could be many times that amount, so the main fiscal cost of prohibition after decriminalization relative to outright legalization may be foregone tax revenues, not enforcement costs. Approximately 40 times as many users live within 200 miles of Vermont's borders as live within the state; drug tourism and associated tax revenues will be important considerations, as will be the response of other states. Indeed, if another state legalized with lower taxes, that could undermine the ability to collect taxes on even Vermont residents' purchases.

CONCLUSIONS

Analysis of possible outcomes if Vermont, USA, legalized marijuana reveal that choices about how, and not just whether, to legalize a drug can have profound consequences for the effects on health and social wellbeing, and the choices of one jurisdiction can affect the options and incentives available to other jurisdictions.

Tasty THC: Promises and Challenges of Cannabis Edibles

Food products containing cannabis extract (edibles) have emerged as a popular and lucrative facet of the legalized market for both recreational and medicinal cannabis. The many formulations of cannabis extracts used in edibles present a unique regulatory challenge for policy makers. Though edibles are often considered a safe, discreet, and effective means of attaining the therapeutic and/or intoxicating effects of cannabis without exposure to the potentially harmful risks of cannabis smoking, little research has evaluated how ingestion differs from other methods of cannabis administration in terms of therapeutic efficacy, subjective effects, and safety. The most prominent difference between ingestion and inhalation of cannabis extracts is the delayed onset of drug effect with ingestion. Consumers often do not understand this aspect of edible use and may consume a greater than intended amount of drug before the drug has taken effect, often resulting in profoundly adverse effects. Written for the educated layperson and for policy makers, this paper explores the current state of research regarding edibles, highlighting the promises and challenges that edibles present to both users and policy makers, and describes the approaches that four states in which recreational cannabis use is legal have taken regarding regulating edibles.

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

Perceived social norms of substance use are commonly identified as a risk factor for use. How the strength of association between perceived friends' use and substance use may change across development has not yet been documented. The current analysis considers how the associations between perceived friends' marijuana use and participants' own use of any marijuana in the past year changes from ages 18 to 30 using longitudinal data from the United States national Monitoring the Future study from 1976 to 2014 (N = 30,794 people). Time-varying effect modeling (TVEM) was used to examine the associations between perceived friends' use of marijuana and participants' own annual marijuana use by age, as well as the extent to which these time-varying associations were moderated by sex, race/ethnicity, and parental education. Associations between perceived friends' use and own marijuana use increased with age. In addition, the association between perceived friends' use and own marijuana use significantly varied by demographic groups, such that it was significantly greater for men from ages 19 to 24 and from ages 27 to 30, compared with women; for Whites, compared with other race/ethnicities, across all ages; and for individuals whose parents attended college, compared with those whose parents had a high school education or less, across all ages. Results suggest that perceived friends' marijuana use becomes an even more important marker for increased marijuana use as people age through young adulthood. Therefore, the role of peers in substance use remains crucial beyond adolescence and should be incorporated into intervention strategies for young adults. (PsycINFO Database Record

Decision-Making Does not Moderate the Association between Cannabis Use and Body Mass Index among Adolescent Cannabis Users

OBJECTIVES

Results from research conducted on the association between cannabis use and body mass index (BMI) reveal mixed findings. It is possible that individual differences in decision-making (DM) abilities may influence these associations.

METHODS

This study analyzed how amount of cannabis use, DM performance, and the interaction of these variables influenced BMI and clinical classifications of weight among adolescents (ages 14 to 18 years; 56% male; 77% Hispanic). The sample consisted primarily of cannabis users (n=238) without a history of significant developmental disorders, birth complications, neurological conditions, or history of mood, thought, or attention deficit/hyperactivity disorder at screening. Furthermore, few participants engaged frequently in other drug use (except for alcohol and nicotine).

RESULTS

Analyses revealed that more lifetime cannabis use was associated with a higher BMI and greater likelihood of being overweight/obese. Interactions between DM and cannabis use on BMI were not significant, and DM was not directly associated with BMI.

DISCUSSION

Our findings suggest that among adolescents, cannabis use is associated with a greater BMI regardless of DM abilities and this association is not accounted for by other potential factors, including depression, alcohol use, nicotine use, race, ethnicity, or IQ. (JINS, 2016, 22, 944-949).

Influence of legal status on the uptake of cannabis in young people

PURPOSE OF REVIEW

Policies that limit young people's access to cannabis may reduce early onset of use and minimize health-related harm. This review article provides an update of recent research examining the influence of the cannabis policy frameworks on the use of cannabis by young people.

RECENT FINDINGS

There are significant concerns that ongoing policy changes in favour of legalization will increase the uptake of cannabis by young people. Evidence to support a causal effect of cannabis policy changes on increased uptake by young people is lacking; more time may be needed to assess the impact because the policies are still evolving. Policy changes in favour of legalization were associated with reduced risk perception although this may be a cause or consequence. The need to situate the impact of these policies in the context of specific policy features, social norms and perceptions about cannabis has been highlighted.

SUMMARY

A more nuanced understanding of the impact of the legal status of cannabis on young people is needed to build evidence for future policy options. The impact of these policies may not be immediately apparent but limiting young people's access to cannabis must be prioritized during policy deliberations.

Trends in the disapproval and use of marijuana among adolescents and young adults in the United States: 2002-2013

BACKGROUND

Despite policy changes related to the use and distribution of marijuana in cities and states across the country, few studies have examined changes in disapproval and use of marijuana among American youth.

OBJECTIVES

To examine trends in disapproval and use of marijuana among adolescents and young adults in the United States.

METHOD

We employed nationally representative data spanning the period of 2002-2013. Analyses were based on self-reported measurements from 105,903 younger adolescents (aged 12-14); 110,949 older adolescents (aged 15-17); and 221,976 young adults (aged 18-25).

RESULTS

Between 2002 and 2013 the proportion of adolescents aged 12-14 reporting "strong disapproval" of marijuana use initiation increased significantly from 74.4-78.9%. Concurrently, a significant decrease in past 12-month marijuana use (OR = 0.98, 95% CI = 0.97-0.99) was observed among younger adolescents. No significant trend was observed for marijuana use disapproval among adolescents aged 15-17 between 2002 and 2013. Yet a significant (OR = 0.99, 95% CI = 0.98-0.99) decrease in the past 12-month marijuana use was observed (2002 = 26.2%, 2013 = 21.9%) among this group. Among young adults (aged 18-25), a substantial decrease - from 40.5% in 2002 to 22.6% in 2013 - was observed in the proportion reporting "strong disapproval" of marijuana use initiation; however, increases in the past 12-month use were relatively small among young adults (Δ = 2.21) but statistically significant (OR = 1.02, 95% = 1.01-1.02).

CONCLUSIONS

Changes are underway in the perception and use of marijuana among American youth. However, changes differ in important ways among youth from distinct developmental subgroups.

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.

Marijuana and Other Substance Use Among Motor Vehicle Operators: A Latent Class Analysis

OBJECTIVE

The deleterious effect of multiple-substance use on driving performance is well established, but relatively little research has examined the patterns of drug use among multiple-substance users and its relationship to both alcohol use and adverse driving outcomes.

METHOD

The current study used latent class analysis to examine subgroups of substance users among a population of drivers who screened positively for 2 or more of 13 substances other than alcohol (N = 250). A series of logistic regression analyses was conducted to examine demographic predictors of latent class assignment and class association with adverse driving outcomes.

RESULTS

Four distinct subclasses of users were identified among multiple-substance-using drivers: Class 1 consisted of individuals who demonstrated high levels of all substances indicators (5%). The second class demonstrated high levels of marijuana and cocaine use and lower levels of all other substances (27%). The third class screened high for marijuana and nonmedical prescription opiate analgesics use (36%), whereas the last class demonstrated high nonmedical prescription opiate analgesics and benzodiazepine use (32%). Drivers in Class 2 (marijuana and cocaine users) were more likely to be younger and have a positive breath alcohol concentration than drivers in any other class.

CONCLUSIONS

Because multidrug users show dissimilar characteristics, the propensity of researchers to lump all multiple-substance users together may either erroneously attribute the potentially profound impact of those in the marijuana and cocaine use class to all multiple-substance users or dilute their specific contribution to crash risk.

Declining Prevalence of Marijuana Use Disorders Among Adolescents in the United States, 2002 to 2013

OBJECTIVE

Little is known about recent trends in marijuana use disorders among adolescents in the United States. We analyzed trends in the past-year prevalence of DSM-IV marijuana use disorders among adolescents, both overall and conditioned on past-year marijuana use. Potential explanatory factors for trends in prevalence were explored.

METHOD

We assembled data from the adolescent samples of the 2002 to 2013 administrations of the National Survey on Drug Use and Health (N = 216,852; aged 12-17 years). The main outcome measures were odds ratios describing the average annual change in prevalence and conditional prevalence of marijuana use disorders, estimated from models of marijuana use disorder as a function of year. Post hoc analyses incorporated measures of potentially explanatory risk and protective factors into the trend analyses.

RESULTS

A decline in the past-year prevalence of marijuana use disorders was observed (odds ratio = 0.976 per year; 95% CI = 0.968, 0.984; p < .001). This was due to both a net decline in past-year prevalence of use and a decline in the conditional prevalence of marijuana use disorders. The trend in marijuana use disorders was accounted for by a decrease in the rate of conduct problems among adolescents (e.g., fighting, stealing).

CONCLUSION

Past-year prevalence of marijuana use disorders among US adolescents declined by an estimated 24% over the 2002 to 2013 period. The decline may be related to trends toward lower rates of conduct problems. Identification of factors responsible for the reduction in conduct problems could inform interventions targeting both conduct problems and marijuana use disorders.

Young People's More Permissive Views About Marijuana: Local Impact of State Laws or National Trend?

OBJECTIVES

To determine whether state medical marijuana laws "send the wrong message," that is, have a local influence on the views of young people about the risks of using marijuana.

METHODS

We performed multilevel, serial, cross-sectional analyses on 10 annual waves of the US National Survey on Drug Use and Health (2004-2013) nationally and for states with marijuana laws using individual- and state-level controls.

RESULTS

Living in medical marijuana states was associated with more permissive views regarding marijuana across 5 different measures. However, these associations became non-statistically significant after we adjusted for state-level differences. By contrast, there was a consistent and significant national time trend toward more permissive attitudes, which was less pronounced among children of middle school age than it was among their older counterparts.

CONCLUSIONS

Passing medical marijuana laws does not seem to directly affect the views of young people in medical marijuana states. However, there is a national trend toward young people taking more permissive views about marijuana independent of any effects within states.

Commentary: Adolescent Marijuana Use and Mental Health Amidst a Changing Legal Climate

OBJECTIVE

The purpose of this commentary was to briefly summarize the literature on the relationship between adolescent marijuana use and mental health and how policy changes surrounding marijuana decriminalization and legalization might impact this relationship. 

METHODS

 A comprehensive literature search on adolescent marijuana use, mental health, and the impact of decriminalization and legalization was conducted. Findings are briefly summarized and discussed. 

RESULTS

 Although there is a great deal of ambiguity regarding the causal direction of marijuana use and mental health problems, what can safely be gleaned from this body of research is that early and frequent use of marijuana during adolescence is associated with the development of more psychiatric-related problems than occasional use or nonuse. 

CONCLUSIONS

 Until there is greater clarity in this domain, clinicians should continue to screen adolescent patients for marijuana use as well as mental health difficulties, but may need to be more thoughtful about screening among early adolescents, if in fact a shift in the age of marijuana uptake occurs amidst policy changes.

Process evaluation of a technology-delivered screening and brief intervention for substance use in primary care

Psychotherapy process research examines the content of treatment sessions and their association with outcomes in an attempt to better understand the interactions between therapists and clients, and to elucidate mechanisms of behavior change. A similar approach is possible in technology-delivered interventions, which have an interaction process that is always perfectly preserved and rigorously definable. The present study sought to examine the process of participants' interactions with a computer-delivered brief intervention for drug use, from a study comparing computer- and therapist-delivered brief interventions among adults at two primary health care centers in New Mexico. Specifically, we sought to describe the pattern of participants' (N=178) choices and reactions throughout the computer-delivered brief intervention, and to examine associations between that process and intervention response at 3-month follow-up. Participants were most likely to choose marijuana as the first substance they wished to discuss (n = 114, 64.0%). Most participants indicated that they had not experienced any problems as a result of their drug use (n = 108, 60.7%), but nearly a third of these (n = 32, 29.6%) nevertheless indicated a desire to stop or reduce its use; participants who did report negative consequences were most likely to endorse financial or relationship concerns. However, participant ratings of the importance of change or of the helpfulness of personalized normed feedback were unrelated to changes in substance use frequency. Design of future e-interventions should consider emphasizing possible benefits of quitting rather than the negative consequences of drug use, and-when addressing consequences-should consider focusing on the impacts of substance use on relationship and financial aspects. These findings are an early but important step toward using process evaluation to optimize e-intervention content.

Divergent marijuana trajectories among men: Socioeconomic, relationship, and life satisfaction outcomes in the mid-30s

BACKGROUND

Given recent changes in marijuana policy in the United States, it is important to understand the long-term effects of marijuana use on adult functioning. We examined whether men who displayed different trajectories of marijuana use from adolescence through emerging adulthood (age ∼15-26) differed in terms of socioeconomic, social, and life satisfaction outcomes in their mid-30s.

METHODS

Data came from a longitudinal sample of men who were recruited in early adolescence (N=506) and followed into adulthood. Four trajectory groups based on patterns of marijuana use from adolescence into emerging adulthood were compared on adult outcomes (age ∼36) before and after controlling for co-occurring use of other substances and several pre-existing confounding factors in early adolescence. The potential moderating effect of race was also examined.

RESULTS

Although there were initially group differences across all domains, once pre-existing confounds and co-occurring other substance use were included in the model, groups only differed in terms of partner and friend marijuana use. Chronic marijuana users reported the highest proportions of both. Frequent and persistent marijuana use was associated with lower socioeconomic status (SES) for Black men only.

CONCLUSIONS

After statistically accounting for confounding variables, chronic marijuana users were not at a heightened risk for maladjustment in adulthood except for lower SES among Black men. Chronic users were more likely to have friends and partners who also used marijuana. Future studies should take into account pre-existing differences when examining outcomes of marijuana use.

Trends Among U.S. High School Seniors in Recent Marijuana Use and Associations With Other Substances: 1976-2013

PURPOSE

The purpose of this study was to describe historical trends in rates of recent substance use and associations between marijuana and other substances, among U.S. high school seniors by race and gender.

METHODS

Data from Monitoring the Future (1976-2013; N = 599,109) were used to estimate historical trends in alcohol use, heavy episodic drinking (HED), cigarette use, and marijuana use. We used time-varying effect models to flexibly estimate changes in associations of substance use behaviors.

RESULTS

Past-month marijuana use rates peaked in the 1970s, declined through 1990, then rose again to reach levels of use of more than 20% for both black and white participants. Recent years show increasing disparities across groups such that males, and in particular black youth, are on a trajectory toward higher use. This rise in marijuana use is particularly concerning among black youth, with rates far exceeding those for cigarette use and HED. The association of marijuana use with both cigarette use and HED is particularly high in recent years among black adolescents.

CONCLUSIONS

Substance use recently declined among high school seniors, except for marijuana use, particularly among black youth. The increasing association between marijuana and other substances among black adolescents suggests future amplification in critical health disparities.

The effect of medical cannabis laws on juvenile cannabis use

BACKGROUND

A number of states in the United States legally allow the use of cannabis as a medical therapy to treat an illness or to alleviate symptoms. Concern persists as to whether these types of laws are increasing juvenile recreational cannabis use. It is also plausible that medical cannabis laws engender an escalation of illicit non-cannabis drug use among juveniles because cannabis is frequently considered to be a gateway drug.

METHODS

This study uses longitudinal data drawn from the National Survey on Drug Use and Health for the 50 U.S. states and a cross-sectional pooled-time series research design to investigate the effect of medical cannabis laws on juvenile cannabis use and on juvenile non-cannabis illicit drug use. Our study period encompasses five measurement periods calibrated in two-year intervals (2002-2003 to 2010-2011). This research design is advantageous in that it affords us the ability not only to assess the effect of the implementation of medical cannabis laws on juvenile drug use, but also to consider other state-specific factors that may explain variation in drug use that cannot be accounted for using a single time series.

RESULTS

Findings show that medical cannabis laws amplify recreational juvenile cannabis use. Other salient predictors of juvenile cannabis use at the state-level of analysis include perceived availability of cannabis, percent of juveniles skipping school, severity of perceived punishment for cannabis possession, alcohol consumption, percent of respondents with a father residing in household, and percent of families in the state receiving public assistance. There is little empirical evidence to support the view that medical cannabis laws affect juveniles' use of illicit non-cannabis drugs.

CONCLUSION

Based on our findings, it seems reasonable to speculate that medical cannabis laws amplify juveniles' use of cannabis by allaying the social stigma associated with recreational cannabis use and by placating the fear that cannabis use could potentially result in a negative health outcome.