Longitudinal trajectories of marijuana use from adolescence to young adulthood

Frequency is not enough: Characterizing heterogenous patterns of cannabis use intensity among reservation-area American Indian youth

BACKGROUND

Reservation-area American Indian (AI) youth use cannabis at significantly higher rates than their national counterparts. This discrepancy is concerning, as cannabis use-particularly heavy use-can negatively impact adolescents' health. Studies primarily use frequency to classify cannabis use intensity; however, frequency alone may not fully capture heterogenous patterns of use. This study aimed to classify AI adolescents' cannabis use based on multiple intensity indicators, and to investigate interclass differences in problematic characteristics and outcomes of use.

METHODS

Participants were 799 reservation-area AI youth (7-12th grade) reporting 12-month cannabis use. Latent Class Analysis (LCA) was used to distinguish cannabis use intensity patterns based on frequency, typical intoxication levels and duration. Auxiliary tests using R3STEP and BCH 3-step procedures were used to assess class predictors (age, initiation age, sex) and interclass differences in simultaneous drug use, stress-motivated use, problems quitting and cannabis-related consequences.

RESULTS

Four classes emerged: Light Use (LU; 19 %), Occasional Intoxication (OI; 32 %), Mid-frequency Use(MU; 28 %), and Heavy Use (HU; 21 %). Age and initiation age correlated with membership odds in a heavier use class. Interclass differences in problematic characteristics and outcomes occurred between all classes, particularly for stress-motivated use and cannabis-related consequences-with HU reporting the most problematic characteristics and negative outcomes.

CONCLUSION

These findings suggest that accounting for multiple dimensions of usage intensity may be important in studies examining cannabis use and related problems among AI adolescents. Tailoring intervention programming to address complex cannabis use patterns, with particular focus on stress-coping skills and harm reduction, can ensure AI youth most at risk for cannabis problems gain maximal benefit from prevention efforts.

Risk-Taking Is Associated with Decreased Subjective Value Signals and Increased Prediction Error Signals in the Hot Columbia Card Task

It remains a pressing concern to understand how neural computations relate to risky decisions. However, most observations of brain-behavior relationships in the risk-taking domain lack a rigorous computational basis or fail to emulate of the dynamic, sequential nature of real-life risky decision-making. Recent advances emphasize the role of neural prediction error (PE) signals. We modeled, according to prospect theory, the choices of n = 43 human participants (33 females, 10 males) performing an EEG version of the hot Columbia Card Task, featuring rounds of sequential decisions between stopping (safe option) and continuing with increasing odds of a high loss (risky option). Single-trial regression EEG analyses yielded a subjective value signal at centroparietal (300-700 ms) and frontocentral (>800 ms) electrodes and in the delta band, as well as PE signals tied to the feedback-related negativity, P3a, and P3b, and in the theta band. Higher risk preference (total number of risky choices) was linked to attenuated subjective value signals but increased PE signals. Higher P3-like activity associated with the most positive PE in each round predicted stopping in the present round but not risk-taking in the subsequent round. Our findings indicate that decreased representation of decision values and increased sensitivity to winning despite low odds (positive PE) facilitate risky choices at the subject level. Strong neural responses when gains are least expected (the most positive PE on each round) adaptively contribute to safer choices at the trial-by-trial level but do not affect risky choice at the round-by-round level.

Gender-based differences in abstention and desistance from drug use among American Indian adolescents

Informed by the social control theoretical perspective, this study intends to identify the factors more likely to differentiate American Indian (AI) adolescents who never used illicit drugs (abstainers) and those who used drugs in the past but did not report recent drug usage (desisters) from their peers who reported lifetime and recent drug usage (persisters). This secondary analysis is based on data from a multi-site study conducted between 2009 and 2013. It is based on a gender-balanced sample (N = 3,380) of AI adolescents (50.50% male; Mean age = 14.75; SD = 1.69) representing the major AI languages and cultural groups in the U.S. Half of the AI adolescents reported lifetime drug use (50.40%), 37.50% never used drugs, and 12.10% stopped using drugs. When controlling for the variables included in the analysis, AI boys were significantly more likely than AI girls to desist from drug use. Both boys and girls who never used drugs tended to be younger, were less likely to have delinquent friends and a lower level of self-control, had stronger bonds to school, but lower levels of family attachment, and reported increased parental supervision. Compared to drug users, desisters associated significantly less with delinquent peers. While school attachment, self-control, and parental monitoring did not differentiate female desisters from female drug users, adolescent boys who desisted from drug use were more likely to report higher levels of school attachment and parental monitoring and their level of self-control was less likely to be low.

Parental influences on marijuana use in emerging adulthood

The purpose of this study was to gain a clearer understanding of the relation between parental relationship qualities and overall emerging adulthood (EA) marijuana use processes. The present study drew from an ethnically and socioeconomially diverse sample of EAs (ages 19-22) and their parents (n = 470) from the Pacific Northwest region. This study used parent-report and child-report data to capture measures of parenting and EA marijuana use outcomes. Latent Class Growth Analysis (LCGA) was used to model trajectories of marijuana use and risk factor analyses were used to examine how marijuana group membership varied by covariates and parental relationship qualities. Results revealed that lower levels of family cohesion and quality of parent-child communication were more likely to predict membership in the high-using groups and moderate-decreasing user groups in comparison to low-to-non users. Results also indicated that lower levels of frequency of parent-child communication were more likely to predict membership in the high-users group compared to the low-to-non users. Regarding parent knowledge of marijuana use, trends toward congruence and underestimation of EA marijuana use predicted membership in the high-using and moderate-decreasing groups compared to the low-to-non users. Study results indicate EAs in their early 20s may be more likely to engage in healthy decision-making regarding marijuana use in an environment that includes warm, supportive parent-child relationships where parents are aware of their EAs use without focusing on their EA's perceptions of risk. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

First-Year Trajectories of Medical Cannabis Use Among Adults Taking Opioids for Chronic Pain: An Observational Cohort Study

OBJECTIVE

To describe first-year trajectories of medical cannabis use and identify characteristics associated with patterns of use in a cohort of adults using opioids for chronic pain.

DESIGN

Latent class trajectory analysis of a prospective cohort study using data on the 14-day frequency of medical cannabis use.

SETTING

A large academic medical center and four medical cannabis dispensaries in the New York City metropolitan area.

SUBJECTS

Adults with chronic pain using opioids and newly certified for medical cannabis in New York between 2018 and 2020.

METHODS

Using latent class trajectory analysis, we identified clusters of participants based on the 14-day frequency of medical cannabis use. We used logistic regression to determine factors associated with cluster membership, including sociodemographic characteristics, pain, substance use, and mental health symptoms.

RESULTS

Among 99 participants, the mean age was 53 years; 62% were women, and 52% were White. We identified three clusters of medical cannabis use: infrequent use (n = 30, mean use = 1.5 days/14-day period), occasional use (n = 28, mean = 5.7 days/14-day period), and frequent use (n = 41, mean = 12.1 days/14-day period). Within clusters, use patterns did not vary significantly over 52 weeks. Differences were observed in two sociodemographic variables: Frequent (vs infrequent) use was associated with non-Hispanic White race/ethnicity (adjusted odds ratio 4.54, 95% confidence interval 1.49-14.29), while occasional (vs infrequent) use was associated with employment (adjusted odds ratio 13.84, 95% confidence interval 1.21-158.74).

CONCLUSIONS

Three clusters of medical cannabis use patterns emerged and were stable over time. Results suggest that structural factors related to race/ethnicity and employment may be major drivers of medical cannabis use, even among adults certified for its use.

Tobacco and cannabis poly-substance and poly-product use trajectories across adolescence and young adulthood

Tobacco and cannabis poly-substance and poly-product use is common in adolescents and young adults (AYAs), but few studies have examined developmental trajectories of poly-use. This study characterized the prevalence, patterns, and racial/ethnic and sex differences of developmental trajectories of use and poly-use of 8 different widely-marketed tobacco and cannabis products across adolescence and young adulthood. 3322 AYAs from Los Angeles, California completed 5 surveys from fall of 11th grade (2015) to 1-2 years post-high school (2018-2019). Self-reported past 30-day use of three tobacco (nicotine vaping, cigarette, hookah) and five cannabis (combustible, blunt, edible, vaping, dabbing) products were analyzed using parallel growth mixture modeling to identify tobacco and cannabis use and poly-use trajectories; racial/ethnic and sex differences were evaluated as correlates of trajectory membership. Five trajectories were identified: Non-Users (58.6%); Young Adult-Onset Poly-Substance/Poly-Product Users (15.8%); Decreasing Moderate Poly-Substance/Poly-Product Users (9.8%); Increasing Predominant Cannabis Poly-Product Users (8.3%); and Chronic Poly-Substance/Poly-Product Users (7.3%). Within trajectories, developmental patterns of each tobacco and cannabis product were similar. Non-Hispanic White (vs. non-NH White) participants had higher odds of belonging to the Chronic Poly-Substance/Poly-Product Users (vs. Non-Users) trajectory (aOR = 2.24[1.37,3.67]); females (vs. males) had higher odds of belonging to the Young Adult-Onset Poly-Substance/Poly-Product Users (vs. Non-Users) trajectory (aOR = 1.30[1.02-1.66]). Tobacco and cannabis poly-substance use patterns, including use of various products, appear to be a common developmental trajectory during some point in adolescence and young adulthood. The interplay of tobacco and cannabis poly-substance/poly-product use merit attention in prevention and regulatory policies to protect AYA health.

A Monte Carlo evaluation of growth mixture modeling

Growth mixture modeling (GMM) and its variants, which group individuals based on similar longitudinal growth trajectories, are quite popular in developmental and clinical science. However, research addressing the validity of GMM-identified latent subgroupings is limited. This Monte Carlo simulation tests the efficiency of GMM in identifying known subgroups (k = 1-4) across various combinations of distributional characteristics, including skew, kurtosis, sample size, intercept effect size, patterns of growth (none, linear, quadratic, exponential), and proportions of observations within each group. In total, 1,955 combinations of distributional parameters were examined, each with 1,000 replications (1,955,000 simulations). Using standard fit indices, GMM often identified the wrong number of groups. When one group was simulated with varying skew and kurtosis, GMM often identified multiple groups. When two groups were simulated, GMM performed well only when one group had steep growth (whether linear, quadratic, or exponential). When three to four groups were simulated, GMM was effective primarily when intercept effect sizes and sample sizes were large, an uncommon state of affairs in real-world applications. When conditions were less ideal, GMM often underestimated the correct number of groups when the true number was between two and four. Results suggest caution in interpreting GMM results, which sometimes get reified in the literature.

Cannabis use disorder trajectories and their prospective predictors in a large population-based sample of young Swiss men

BACKGROUND AND AIMS

Cannabis use disorder (CUD) is frequent in adolescence and often goes into remission towards adulthood. This study aimed to estimate trajectories of CUD severity (CUDS) in Swiss men aged from 20 to 25 years and to identify prospective predictors of these trajectories.

DESIGN

Latent class growth analysis of self-reported CUDS in a cohort study with three data collection waves.

SETTING

A general population sample of young Swiss men.

PARTICIPANTS

A total of 5987 Swiss men assessed longitudinally at the mean ages of 20, 21.5 and 25 years.

MEASUREMENTS

Latent CUDS in the last 12 months was measured at each wave with the Cannabis Use Disorders Identification Test-Revised (CUDIT-R). Predictors of CUDS trajectories, measured at age 20, were from six domains: factors related to cannabis use, family, peers, other substance use, mental health and personality.

FINDINGS

We distinguished four CUDS trajectories: stable-low (88.2%), decreasing (5.2%), stable-high (2.6%) and increasing (4.0%). Predictors were generally associated with higher odds of membership in the decreasing and stable-high trajectory (versus the stable-low), and to a lesser degree with higher odds of membership in the increasing trajectory. Bivariate predictors of persistent high CUDS (stable-high versus decreasing trajectory) were major depression severity [odds ratio (OR) = 1.19, 95% confidence interval (CI) = 1.01, 1.40], attention deficit hyperactivity disorder severity (OR = 1.25, 95% CI = 1.04, 1.51), antisocial personality disorder severity (OR = 1.18, 95 % CI = 1.04, 1.34), relationship with parents (OR = 0.74, 95% CI = 0.63, 0.88), number of friends with drug problems (OR = 1.33, 95% CI = 1.11, 1.60) and the personality dimensions neuroticism-anxiety (OR = 1.35, 95% CI = 1.11, 1.65) and sociability (OR = 0.78, 95% CI = 0.62, 0.97).

CONCLUSIONS

Factors associated with persistent cannabis use disorder in young Swiss men include cannabis use, cannabis use disorder severity, mental health problem severity, relationship with parents (before the age of 18), peers with drug problems and the personality dimensions neuroticism-anxiety and sociability at or before age 20. Effect sizes may be small, and predictors are mainly associated with persistence via higher severity at age 20 years.

Smoke in the air - Associations between experimentation with cannabis and the use of tobacco and nicotine products among 15-16-year-old school students

BACKGROUND

Cannabis is the most popular illicit drug among adolescents in developed countries, including Finland. The aim of this study was to estimate 1) how cannabis experimentation among Finnish adolescents changed between 2003 and 2019, and 2) whether the associations between cannabis experiments and factors related to it, especially the use of tobacco and nicotine products, changed during the same time period.

METHODS

The analyses are based on the European School Survey Project on Alcohol and Other Drugs data, collected from Finnish adolescents aged 15 to 16 in 2003, 2007, 2011, 2015, and 2019 (N = 20,630).

RESULTS

Experimentation with cannabis among Finnish adolescents has increased since the beginning of our follow-up. At the same time, alcohol use and smoking have decreased markedly, and attitudes toward cannabis use have become more relaxed. The association between smoking and cannabis experimentation has become weaker over time. However, the use of tobacco and nicotine products, especially polytobacco, is still a strong risk factor for experimentation with cannabis. The higher the number of tobacco or nicotine products used, the higher the probability for cannabis experimentation.

CONCLUSIONS

Experimentation with cannabis has previously been concentrated predominantly on adolescents who smoke, but recently non-smokers are increasingly trying cannabis. It is possible that alternative ways of using cannabis may have increased its use. Despite the strict cannabis policy in Finland, its use has increased, which may be an indication that youth cultures and images of different substances play a significant role in adolescents experimenting with cannabis.

Trajectories of Nicotine and Cannabis Vaping and Polyuse From Adolescence to Young Adulthood

IMPORTANCE

Little is known about cannabis vaping trajectories across adolescence and young adulthood or the co-occurrence with nicotine vaping.

OBJECTIVE

To evaluate nicotine vaping and cannabis vaping trajectories from late adolescence to young adulthood (≥18 years of age) and the extent of polysubstance vaping.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective cohort study, 5 surveys (including information on substance vaped) were completed at 10 high schools in the Los Angeles, California, metro area. Students were surveyed at 6-month intervals from fall of 11th grade (October to December 2015; wave 5) through spring of 12th grade (March to June 2017; wave 8) and again approximately 1 to 2 years after high school (October 2018 to October 2019; wave 9).

EXPOSURES

Past 30-day nicotine and cannabis vaping frequency across 5 waves.

MAIN OUTCOMES AND MEASURES

Self-reported frequency of nicotine vaping and cannabis vaping within the past 30 days across 5 time points from late adolescence to young adulthood. Trajectories were measured with these past 30-day use frequencies at each wave. Parallel growth mixture modeling estimated conditional probabilities of polysubstance vaping.

RESULTS

The analytic sample included 3322 participants with at least 1 time point of data (mean [SD] age, 16.50 [0.42] years at baseline; 1777 [53.5%] female; 1573 [47.4%] Hispanic or Latino). Growth mixture modeling identified the 5-trajectory model as optimal for both nicotine vaping and cannabis vaping. Trajectories for nicotine and cannabis vaping were similar (nonusers: 2246 [67.6%] nicotine, 2157 [64.9%] cannabis; infrequent users: 566 [17.0%] nicotine, 608 [18.3%] cannabis; moderate users: 167 [5.0%] nicotine, 233 [7.0%] cannabis; young adult-onset frequent users: 213 [6.4%] nicotine, 190 [5.7%] cannabis; adolescent-onset escalating frequent users: 131 [3.9%] nicotine, 134 [4.0%] cannabis). Males had greater odds of belonging to the adolescent-onset escalating frequent users nicotine (adjusted odds ratio, 2.88; 95% CI, 1.58-5.23; P < .01) and cannabis (adjusted odds ratio, 1.95; 95% CI,1.03-3.66; P < .05) vaping trajectories compared with nonusers. Polysubstance vaping was common, with those in trajectories reflecting more frequent nicotine vaping (adolescent-onset escalating frequent users and young adult-onset frequent users) having a high probability of membership (85% and 93%, respectively) in a cannabis-use trajectory.

CONCLUSIONS AND RELEVANCE

In this cohort study, the prevalence and type of nicotine vaping and cannabis vaping developmental trajectories from late adolescence to young adulthood were similar. Polysubstance vaping was common from late adolescence to young adulthood, particularly among those reporting more frequent vaping use. The findings suggest that public health policy and clinical interventions should address polysubstance vaping in both adolescence and young adulthood.

Social Networking Sites and Perceived Content Influence: An Exploratory Analysis from Focus Groups with French Adolescents

Social networking sites (SNSs) are invested in heavily by marketers aiming to reach a growing number of consumers. Concerns regarding the influence of posts displayed on SNSs in relation to behaviour were raised, in particular the promotion of ill-health behaviour directed to adolescents who may be at risk from suggestible practices. Although adolescents tend to be critical towards traditional forms of advertising, little is known about their perception of influencing strategies developed online, especially where sponsor- and user-generated content coexist. This exploratory study aims to gather information directly from adolescents about their use of SNSs their awareness of the influence that SNS content may have, particularly when it comes to tobacco and alcohol messages. Ten focus groups were conducted with 39 adolescents (11-16 years old; 56.4% male). Qualitative analysis documents the differences associated with adolescents' favourite SNSs. The different parameters linked to each SNS and the expectation to find entertaining content and values associated with friendship may decrease adolescents' perception of potential risk for health associated with SNS use. Authors advocate for the development of educational programs based on eHealth literacy and the use of social marketing techniques to facilitate and motivate adolescents to develop their competences.

Complex cannabis use patterns: Associations with cannabis consequences and cannabis use disorder symptomatology

BACKGROUND

Historically, cannabis researchers have assumed a single mode and product of cannabis (e.g., smoking plant). However, patterns of use, products (e.g., concentrates, edibles), and modes (e.g. blunts, vaporizers) are diversifying. This study sought to: 1) classify cannabis users into groups based on their use of the full range of cannabis products, and 2) examine user group differences on demographics, cannabis consequences and cannabis use disorder (CUD) symptomatology.

METHODS

In a sample of college students (data collected in Fall 2017), who used cannabis in the past year (N = 1390), latent class analysis (LCA) was used to characterize cannabis users. We then added demographic characteristics, cannabis consequences, and CUD symptomatology scores separately to LCA models to examine class differences.

RESULTS

Five unique classes emerged: high-frequency all-product users, high-frequency plant/moderate-frequency edible and concentrate users, low-frequency plant users, moderate-frequency plant and edible users, and low-frequency edible users. Demographic characteristics, cannabis consequences, and CUD symptomatology differed across classes characterized by frequency as well as product.

CONCLUSIONS

Results reflect the increasing variety of cannabis products, modes, and use patterns among college students. In this sample, frequency of use remains a strong predictor of cannabis-related consequences, in addition to type of product. As variation in cannabis use patterns continue to evolve, it is essential for researchers to conduct comprehensive assessments.

Adolescent Cannabis Use and Conduct Problems: The Mediating Influence of Callous-Unemotional Traits

Cannabis use has been linked to an increased risk of engaging in conduct problem behaviors. However, little existing research has considered intervening processes and shared risk factors that may contribute to this association. The current investigation examines whether callous-unemotional traits, which have shown associations with adolescent cannabis use and conduct problem development, may exhibit a mediating influence on this relationship. Using a longitudinal cohort of youth (n = 390) at increased risk for escalating in their use of cannabis, we found that baseline cannabis use (age~15) was associated with higher levels of trait-like conduct problems (ages~16 & 17), even after controlling for important autoregressive and cross-lagged effects, along with a number of other shared risk factors (e.g., co-occuring substance use, age, sex). Findings also revealed that callous-unemotional traits partially mediated this relationship, with the hypothesized model accounting for approximately one-third of the variance in the conduct problem outcome (R2=.34). These results indicate that callous-unemotional traits may play an important intermediary role in the association between cannabis use and the development of problem behaviors.

Adolescent E-cigarette use trajectories and subsequent alcohol and marijuana use

INTRODUCTION

As electronic cigarette (e-cigarette) use has become more prevalent among adolescents, there is a growing body of evidence linking e-cigarette use to the initiation of other substances. Whether there is a threshold level of e-cigarette use that is predictive of other substance use is unknown. The current study examines patterns of e-cigarette use over time and determines whether different patterns of early adolescent e-cigarette use are concurrently and prospectively associated with alcohol and marijuana use in late adolescence.

METHOD

Eight hundred and one adolescents (13-15 years old at baseline recruitment) completed five on-line surveys over a two-year period. Latent class growth analysis was used to model different developmental courses of e-cigarette, alcohol (drinking to intoxication), and marijuana use. Logistic regression was used to test the association between e-cigarette use trajectory patterns and alcohol and marijuana use trajectories.

RESULTS

Three developmental courses of e-cigarette use were identified: 1) high and increasing, 2) low and increasing, and 3) never. Compared to adolescents who had never used e-cigarettes, those in the other two groups were more likely to have been intoxicated and to be in the moderate and increasing marijuana use group.

CONCLUSION

Both high and low levels of e-cigarette use patterns are associated with increasing use of other substances (alcohol and marijuana use) over time. Findings highlight the need for early intervention and prevention of e-cigarette use among adolescents.

Life-course trajectories of cannabis use: a latent class analysis of a New Zealand birth cohort

BACKGROUND AND AIMS

Little is known about how cannabis use over the life-course relates to harms in adulthood. The present study aimed to identify trajectories of cannabis use from adolescence to adulthood and examine both the predictors of these trajectories and adverse adult outcomes associated with those trajectories.

DESIGN

A latent trajectory analysis of a longitudinal birth cohort (from birth to age 35 years).

SETTING AND PARTICIPANTS

General community sample (n = 1065) from New Zealand.

MEASUREMENT

Annual frequency of cannabis use (ages 15-35 years); childhood family and individual characteristics (birth to age 16 years); measures of adult outcomes (substance use disorders, ages 30-35 years; mental health disorders, ages 30-35 years; socio-economic outcomes at age 35 years; social/family outcomes at age 35 years).

FINDINGS

A six-class solution was the best fit to the data. Individuals assigned to trajectories with higher levels of cannabis use were more likely to have experienced adverse childhood family and individual circumstances. Membership of trajectories with higher levels of use was associated with increased risk of adverse outcomes at ages 30-35 years. Adjustment of these associations for the childhood family and individual predictors largely did not reduce the magnitude of the associations.

CONCLUSIONS

In New Zealand, long-term frequent cannabis use, or transition to such use, appears to be robustly associated with diverse harms in adulthood.

Intergenerational marijuana use: A life course examination of the relationship between parental trajectories of marijuana use and the onset of marijuana use by offspring

Prior research documents intergenerational (IG) continuity in marijuana use, with most work adopting a life course perspective. Incorporating a methodology that allows for the measurement of "patterns of behavior" instead of singular aspects of parent marijuana use (e.g., age of onset or frequency at any one age or ages), we investigated the simultaneous effects of parental age of onset, frequency, and duration of marijuana use across 3 periods of the life course (i.e., adolescence, emerging adulthood, and adulthood) on the timing of first marijuana use among offspring. Using prospective data from 2 companion studies, the Rochester Youth Development Study and the Rochester Intergenerational Study, we used group-based trajectory models to estimate trajectories (or patterns) of parental marijuana use spanning ages 14 to 31 among a birth cohort of 462 parents. We then examined the relationship between parental trajectories of marijuana use and the timing of the onset of marijuana use through age 25 among firstborn offspring. Both late-onset persistent use by parents and increasing chronic use spanning adolescence to adulthood by parents were associated with an increased likelihood of onset of marijuana use among offspring. The results underscore the importance of patterns of marijuana use for IG continuity in contrast to singular measures (e.g., age of onset among parents), which can obfuscate important IG patterns of continuity. Prevention and intervention programs should consider the entire history of parent use to better identify children most at risk for the onset of marijuana use in adolescence and emerging adulthood. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Relationships between marijuana use, severity of marijuana-related problems, and health-related quality of life

Studies on the relationships between marijuana use and quality of life have reported mixed findings. Based on a survey of 123 marijuana users conducted in Los Angeles during 2017-2018, we investigated the relationships between marijuana use frequency, severity of marijuana-related problems, and health-related quality of life (HRQoL). Results indicated that (1) marijuana use frequency was positively related to severity of marijuana-related problems; (2) severity of marijuana-related problems was negatively related to mental domain of HRQoL but was not significantly related to physical domain of HRQoL; and (3) marijuana use frequency was positively associated with mental health symptoms and physical health conditions, and both in turn were negatively linked to mental and physical domains of HRQoL, respectively. Reduction of marijuana-related problems and mitigation of mental and physical health problems may improve HRQoL among marijuana users. The study findings may contribute to developing treatment interventions for marijuana use that simultaneously address marijuana-related problems and associated mental and physical issues.

Effects of Adolescent Cannabis Use on Motivation and Depression: A Systematic Review

Purpose of review

This article reviews recent behavioral and neuroimaging studies to elucidate whether adolescent cannabis use is related to reduced motivation and increased risk of depression.

Recent findings

Recent work suggests that heavy adolescent cannabis use predicts poorer educational outcomes, often presumed to reflect reduced academic motivation, as well as increased levels of depressive symptoms. However, evidence of a link between cannabis use and general motivation was lacking. Factors such as concurrent alcohol and tobacco use, trajectories of cannabis use during adolescence, and cannabis-related changes in underlying neurocircuitry may impact associations among cannabis use, motivation, and depression.

Summary

Heavy adolescent cannabis use is associated with poorer educational outcomes and increased levels of depressive symptoms. The role of depression in how cannabis may affect motivation, broadly, is not yet clear, as most studies have not examined associations among all three constructs. Future work should explore possible overlap between cannabis effects on motivation and depression, and clarify the temporality of these associations.

Cross-domain correlates of cannabis use disorder severity among young adults

BACKGROUND

Correlates of cannabis use and dependence among young adults have been widely studied. However, it is not known which factors are most strongly associated with severity of cannabis use dependence (CUD) severity. Identification of the salient correlates of CUD severity will be of increasing clinical significance as use becomes more socially normative.

METHODS

This study used a data-driven, hypothesis-free approach to examine the most robust correlates of CUD severity among a sample of 76 young adults (ages 18 to 25 years) who used cannabis at least weekly. Seventy-one candidate variables were examined for association with CUD severity. These included demographic variables, self-reported and psychodiagnostic assessments of mood and anxiety, self-reported measures of personality, cannabis and other substance use characteristics, and objective and subjective measures of cognition.

RESULTS

Of the 71 candidate variables considered, 27 were associated with CUD severity on a univariate level at a p-value ≤.20. Correlates of CUD severity in the multivariable model using stepwise selection were: more frequent cannabis use in the past 90 days, greater expectancies that cannabis causes cognitive and behavioral impairment, greater self-reported metacognitive deficits, greater anxiety, and lower reaction time variability on a test of sustained attention. Internal validation tests support high prediction accuracy of all variables in the multivariable model, except for lower reaction time variability.

CONCLUSIONS

Cannabis use frequency, beliefs about use, perceived cognitive abilities, and anxiety are robustly associated with CUD severity in young adult, regular cannabis users, and may be important in guiding prevention and treatment efforts.

Young adult longitudinal patterns of marijuana use among US National samples of 12th grade frequent marijuana users: a repeated-measures latent class analysis

BACKGROUND AND AIMS

Long-term frequent marijuana use is associated with significant negative outcomes, yet little is known about the longitudinal course of marijuana use among those who start frequent use during adolescence. Objectives are (a) to identify latent patterns of within-person marijuana use from ages 19-30 years among 12th graders reporting frequent marijuana use, (b) to examine if membership in identified patterns has changed across historical time and (c) to examine if key covariates differentiate class membership.

DESIGN, SETTING, PARTICIPANTS

Longitudinal, national US panel data from 4423 individuals [53.4% of the eligible sample; 2744 (62%) males] who reported frequent marijuana use in 12th grade (modal age 18 years; senior year cohorts 1976-2006) followed biennially from ages 19/20 to 29/30.

MEASUREMENTS

Self-reported past 30-day marijuana use (frequent use defined as use on 20+ occasions), demographics, college graduation, marriage and parenthood.

FINDINGS

Repeated-measures latent class analysis (RMLCA) identified five latent classes of past 30-day marijuana use from ages 19/20 to 29/30: continued frequent users (estimated membership 23.4%); frequent to non-frequent users (15.5%); consistent non-frequent users (18.4%); non-frequent users to discontinuers (19.5%); and discontinuers (23.2%). In multivariable models, membership in the highest-risk latent class (continued frequent users) versus one or more of the lower-risk latent classes was more likely for recent cohorts (P = 0.038 to <0.001), as well as those who did not marry (P = 0.039 to < 0.001) or become parents (P = 0.001) by modal age 29/30.

CONCLUSIONS

Nearly one in four 12th grade (modal age 18 years) frequent marijuana users in the US continues to report high frequency use to age 30; the proportion continuing high frequency use across young adulthood has increased among more recent cohorts.

Patterns of adolescent tobacco and alcohol use as predictors of illicit and prescription drug abuse in minority young adults

The present longitudinal study examined the relationship between patterns of cigarette smoking and alcohol use during adolescence and illicit drug abuse (DA) and prescription drug abuse (PDA) in early adulthood. The sample consisted of 984 predominantly minority young adults (57% women) who completed (a) six annual surveys as adolescents attending New York City public schools (grades 7 through 12) and (b) a follow-up telephone interview as young adults (mean age = 23). Findings from a series of latent growth models indicated that growth in cigarette smoking and alcohol use during adolescence each independently predicted DA in adulthood. Baseline levels of alcohol use in 7th grade also predicted DA in adulthood. Growth in alcohol consumption during adolescence predicted PDA in young adulthood. Results indicate that an escalation during adolescence in the use of substances that are legal for adults (cigarettes and alcohol) contributes to greater DA and PDA in young adulthood. One implication of these findings is that interventions that can prevent cigarette smoking and alcohol use during adolescence may also reduce DA and PDA in young adults.

Exploring the relationship between polygenic risk for cannabis use, peer cannabis use and the longitudinal course of cannabis involvement

BACKGROUND AND AIMS

Few studies have explored how polygenic propensity to cannabis use unfolds across development, and no studies have yet examined this question in the context of environmental contributions such as peer cannabis use. Outlining the factors that contribute to progression from cannabis initiation to problem use over time may ultimately provide insights into mechanisms for targeted interventions. We sought to examine the relationships between polygenic liability for cannabis use, cannabis use trajectories from ages 12-30 years and perceived peer cannabis use at ages 12-17 years.

DESIGN

Mixed-effect logistic and linear regressions were used to examine associations between polygenic risk scores, cannabis use trajectory membership and perceived peer cannabis use.

SETTING

United States.

PARTICIPANTS

From the Collaborative Study on the Genetics of Alcoholism (COGA) study, a cohort of 1167 individuals aged 12-26 years at their baseline (i.e. first) interview.

MEASUREMENTS

Key measurements included life-time cannabis use (yes/no), frequency of past 12-month cannabis use, maximum life-time frequency of cannabis use, cannabis use disorder (using DSM-5 criteria) and perceived peer cannabis use. Polygenic risk scores (PRS) were created using summary statistics from a large (n = 162 082) genome-wide association study (GWAS) of cannabis use.

FINDINGS

Three trajectories reflecting no/low (n = 844), moderate (n = 137) and high (n = 186) use were identified. PRS were significantly associated with trajectory membership [P = 0.002-0.006, maximum conditional R2  = 1.4%, odds ratios (ORs) = 1.40-1.49]. Individuals who reported that most/all of their best friends used cannabis had significantly higher PRS than those who reported that none of their friends were users [OR = 1.35, 95% confidence interval (CI) = 1.04, 1.75, P = 0.023]. Perceived peer use itself explained up to 11.3% of the variance in trajectory class membership (OR = 1.50-4.65). When peer cannabis use and the cannabis use PRS were entered into the model simultaneously, both the PRS and peer use continued to be significantly associated with class membership (P < 0.01).

CONCLUSIONS

Genetic propensity to cannabis use derived from heterogeneous samples appears to correlate with longitudinal increases in cannabis use frequency in young adults.

Patterns and Correlates of Tobacco and Cannabis co-use by Tobacco Product Type: Findings from the Virginia Youth Survey

BACKGROUND

Cannabis use is more common among tobacco users than nonusers, and co-use (i.e., use of both substances individually) may be increasing. Better understanding of patterns and correlates of co-use is needed. The current study aimed to compare rates and correlates of tobacco and cannabis co-use by tobacco product among youth.

METHODS

High school students who completed the 2013 Virginia Youth Survey and reported past 30-day tobacco use (cigarette, smokeless tobacco, cigar) were included (n = 1390). Prevalence of past 30-day tobacco-only and cannabis co-use was calculated. Demographic, tobacco, and other substance use characteristics were compared by co-use status. Multivariate logistic regression models examined correlates of co-use overall and by tobacco product.

RESULTS

Over half of tobacco users were co-users. Poly-tobacco use, particularly combusted tobacco, was more prevalent among co-users. Past 30-day alcohol use and lifetime other illegal drug use/prescription drug misuse were common correlates of co-use. Black Non-Hispanic (NH) race/ethnicity was associated with co-use when restricted to cigarette users. "Other" race/ethnicity was associated with co-use in the overall model and when restricted to cigar users. Past 30-day cigarette smoking was associated with co-use in all models except among cigar smoking co-users. Conclusions/Importance: Rates and correlates of tobacco and cannabis co-use were not uniform and differed by tobacco product type. Tobacco and cannabis co-users may be at greater risk for negative health effects associated with inhaled tobacco and other risky substance use. The efficacy of prevention efforts may be improved if risk factors associated with product-specific co-use are considered.

Marijuana Use among Young Adults: Who Quits and Why?

Objective

In this study, we examined: (1) differences among never, current, and former young adult marijuana users; and (2) reasons for use and cessation.

Methods

We conducted interviews with 57 young adults (including 46 marijuana users) enrolled in a longitudinal study of 3418 young adults and a survey in this cohort (N = 2866). Participants reporting former but not current use on the survey (N = 607) completed the Reasons for Marijuana Cessation section.

Results

Interview data indicated reasons for initiating (or not initiating) use, continued use, and quitting. The Reasons for Marijuana Cessation scale included 2 factors: (1) Instrumentality and 2) Social/Legal reasons.

Conclusions

These findings might inform theoretical frameworks upon which marijuana cessation occurs and direct future intervention studies.

Interparental conflict and long-term adolescent substance use trajectories: The role of adolescent threat appraisals

Although interparental conflict (IPC) has been linked directly and indirectly (via adolescents' appraisals) with a wide range of adolescent outcomes, little is known about the implications of IPC and related adolescent threat appraisals for substance use. Drawing on the cognitive-contextual framework, we test competing hypotheses about how IPC may impact adolescent substance use outcomes, specifically testing whether (a) threat appraisals are directly related to escalation in alcohol and tobacco use over adolescence, or (b) threat appraisals are indirectly associated with substance use through their impact on adolescent internalizing problems. Family data from 768 2-caregiver families were analyzed for this study. Adolescents (53% female) were followed on 7 occasions starting in the fall of 6th grade (mean age = 11.3 years) through the spring of 11th grade. IPC and family demographic data were collected from parents. Youth provided data on their appraisals of conflict, internalizing problems, and substance use. Using longitudinal growth curve models, findings supported threat appraisals as a direct risk factor for escalating cigarette use, but not escalating alcohol use, during adolescence. In the alcohol trajectory model, IPC was a direct predictor of increases in alcohol use over time. These findings indicate that high levels of threat appraisals are a specific and direct risk for greater increases in cigarette use over the course of adolescence and that IPC confers risk for increasing rates of alcohol use over adolescence. (PsycINFO Database Record

Trajectories of risk behaviors across adolescence and young adulthood: The role of race and ethnicity

INTRODUCTION

Despite important advances of longitudinal research in substance use behaviors, most studies stratify analyses by gender or race, which limits the ability to directly compare the likelihood of a particular developmental pathway across demographic groups. Thus, there is critical need for well-designed research to examine the associations of race/ethnicity with developmental trajectories of substance use behaviors across adolescence through adulthood.

METHODS

Using an accelerated longitudinal design, we examined behaviors across ages 12-31 from Waves I-IV of the National Longitudinal Study of Adolescent to Adult Health. We performed growth mixture modeling, resulting in estimated trajectories over time. Next, we assessed the association between race/ethnicity and trajectory membership using multinomial logistic regression.

RESULTS

Five trajectories resulted for marijuana use, four for cigarette smoking, three for smokeless tobacco use and number of days drunk, and two trajectories for heavy episodic drinking. Controlling for gender and family socioeconomic status, African Americans and Hispanics were less likely than non-Hispanic Whites to use cigarettes or smokeless tobacco early or to use alcohol heavily.

CONCLUSIONS

Substance use behavior development follows different pathways for US adolescents and young adults, with some individuals experimenting earlier in adolescence and others beginning to use later in adolescence or in early adulthood. We extend developmental knowledge about these behaviors by demonstrating that the patterns of behavior vary by race/ethnicity; members of lower-risk trajectories (those involving later or no initiation of substance use) are more likely to be African American or Hispanic than to be non-Hispanic White.

Nucleus accumbens functional connectivity at age 20 is associated with trajectory of adolescent cannabis use and predicts psychosocial functioning in young adulthood

AIMS

(1) To identify trajectories of cannabis use across adolescence, (2) to measure the influence of cannabis use characteristics on functional connectivity of the nucleus accumbens (NAcc) and (3) to assess whether patterns of functional connectivity related to cannabis use are associated with psychosocial functioning 2 years later.

DESIGN

The Pitt Mother and Child Project (PMCP) is a prospective, longitudinal study of male youth at high risk for psychopathology based on family income and gender.

SETTING

Participants were recruited between age 6 and 17 months from the Women, Infants and Children Nutritional Supplement program (WIC) in the Pittsburgh, Pennsylvania area.

PARTICIPANTS

A total of 158 PMCP young men contributed functional magnetic resonance imaging (fMRI) and substance use data at age 20 years.

MEASUREMENTS

Latent class growth analysis was used to determine trajectories of cannabis use frequency from age 14 to 19 years. Psychophysiological interaction (PPI) analysis was used to measure functional connectivity between the NAcc and prefrontal cortex (PFC). Adolescent cannabis use trajectory, recent frequency of use and age of initiation were considered as developmental factors. We also tested whether functional connectivity was associated with depressive symptoms, anhedonia and educational attainment at age 22.

FINDINGS

We identified three distinct trajectories of adolescent cannabis use, characterized by stable high, escalating or stable low use. The cannabis use trajectory group had a significant effect on NAcc functional connectivity to the medial PFC (F = 11.32, Z = 4.04, P_{family-wise error-corrected (FWE-corr)}  = 0.000). The escalating trajectory group displayed a pattern of negative NAcc-mPFC connectivity that was linked to higher levels of depressive symptoms (r = -0.17, P < .05), anhedonia (r = -0.19, P < .05) and lower educational attainment (t = -2.77, P < .01) at age 22.

CONCLUSIONS

Pattern of cannabis use frequency across adolescence in US youth could have consequences for mood symptoms and educational attainment in early adulthood via altered function in neural reward circuitry.

Prediction of Risk for Boys' Involvement in Drug Use Based on Levels of Self-evaluations in Russia

BACKGROUND

Adolescents often experiment with drug use, which can impact on their health and well-being and increase the probability of problem drug use. Yet, not enough is known about which psychological indicators is related with the initiation of drug use among young adults and have predictive power.

MATERIALS AND METHODS

Participants in this study were 311 boys (school and college students) aged 15-17. Data were collected in the towns of Moscow region. A modified version of Dembo-Rubinstein test was used to assess the self-evaluation (SE). A questionnaire and detection of drugs in urine were used to identify drug users. Binary logistic regression analysis based on SE with the inclusion of interactive effects between predictors was used for prediction of drug use.

RESULTS

Drug users, compared to nondrug users, are characterized by lower actual SE of health, happiness, success in learning, mind and desired SE of appearance, and higher desired SE of relationships with friends. The developed nonlinear regression model for prediction of boys' involvement in drug use among young boys in the towns of Moscow region has a sensitivity of 82.7% at a specificity of 79.0%.

CONCLUSIONS

Dembo-Rubinstein test of SE is a sensitive measure to identify boys at risk of involvement in drug use. Application of the regression model based on SE may contribute to the useful solution in preventing any onset of early drug use.

Trajectories of Marijuana Use among HIV-seropositive and HIV-seronegative MSM in the Multicenter AIDS Cohort Study (MACS), 1984-2013

To construct longitudinal trajectories of marijuana use in a sample of men who have sex with men living with or at-risk for HIV infection. We determined factors associated with distinct trajectories of use as well as those that serve to modify the course of the trajectory. Data were from 3658 [1439 HIV-seropositive (HIV+) and 2219 HIV-seronegative (HIV-)] participants of the Multicenter AIDS Cohort Study. Frequency of marijuana use was obtained semiannually over a 29-year period (1984-2013). Group-based trajectory models were used to identify the trajectories and to determine predictors and modifiers of the trajectories over time. Four distinct trajectories of marijuana use were identified: abstainer/infrequent (65 %), decreaser (13 %), increaser (12 %) and chronic high (10 %) use groups. HIV+ status was significantly associated with increased odds of membership in the decreaser, increaser and chronic high use groups. Alcohol, smoking, stimulant and other recreational drug use were associated with increasing marijuana use across all four trajectory groups. Antiretroviral therapy use over time was associated with decreasing marijuana use in the abstainer/infrequent and increaser trajectory groups. Having a detectable HIV viral load was associated with increasing marijuana use in the increaser group only. Future investigations are needed to determine whether long-term patterns of use are associated with adverse consequences especially among HIV+ persons.

Longitudinal patterns of marijuana use across ages 18-50 in a US national sample: A descriptive examination of predictors and health correlates of repeated measures latent class membership

BACKGROUND

This descriptive study identified latent classes of longitudinal marijuana use from ages 18 through 50 among a national sample; examined covariate associations with class membership regarding use/non-use, use intensity, and use duration; and described associations between identified latent classes and age 50 health outcomes.

METHODS

The study involved collection and primary analysis of data from 9831 individuals first surveyed as 12th graders in the national Monitoring the Future study and followed through modal age 50. Repeated measures latent class analysis was used to identify latent classes based on self-reported past 12-month marijuana use.

RESULTS

Seven latent classes of marijuana use from ages 18 to 50 were identified including Non-users (44%), two classes characterized by shorter-term use patterns (totaling 28%), and four classes characterized by longer-term moderate or heavy use (totaling 28%). Use reduction appeared particularly likely during early and late 20s. Gender, parental education, alcohol/cigarette use, religious commitment, and marital status differentiated use/non-use, use intensity, and use duration after high school. In non-causal models controlling for covariates, longer-term marijuana use classes (where use extended into the late 20s or beyond) were associated with significantly higher odds of negative health outcomes at age 50.

CONCLUSIONS

Approximately 28% of the national sample reported longer-term moderate/heavy marijuana use, which was associated with negative health outcomes at age 50. The early and late 20s may be especially important periods for marijuana use prevention and intervention efforts, which may be strengthened by recognition of characteristics that appear to have significant associations with persistent use.

Marijuana use and service utilization among adolescents 7 years post substance use treatment

BACKGROUND

In an environment of increasingly liberal attitudes towards marijuana use and legalization, little is known about long-term trajectories of marijuana use among clinical samples of adolescents, and how these trajectories relate to health services utilization over time.

METHODS

Latent growth curve analysis was used to identify distinct trajectories of marijuana use in a clinical sample of adolescents (N=391) over 7 years post substance use treatment in an integrated health system. We examined psychiatric problems and polysubstance use associated with the identified trajectory groups using general linear models. Nonlinear mixed-effects logistic regressions were used to examine associations between health services use and the trajectory groups.

RESULTS

We identified three marijuana use trajectory groups: (1) Abstinent (n=117); (2) Low/Stable use (n=174); and (3) Increasing use (n=100). Average externalizing and anxiety/depression scores were significantly lower over time for the Abstinent group compared to the Increasing and Low/Stable groups. The Low Stable and the Increasing group had fewer psychiatric visits over time (p<0.05) and the Low/Stable group used more substance use treatment services over time compared with the Abstinent group (p<0.001).

CONCLUSIONS

Treated adolescents showed distinct marijuana use patterns, one of which indicated a group of adolescents at risk of increased use over time. These individuals have greater psychiatric and polysubstance use over time, but may not be accessing needed services.

Prenatal, perinatal, and adolescent exposure to marijuana: Relationships with aggressive behavior

This manuscript reviews research exploring the relationship between prenatal, perinatal, and adolescent exposure to marijuana and aggressive behavior, including physical aggression. Areas of inquiry include animal research, as well as human research, on prenatal exposure and on marijuana use during adolescence. Potential psychosocial and psychopharmacological mechanisms are identified, as well as relevant confounds. The prenatal marijuana exposure literature provides minimal support for a direct relationship with aggressive behavior in childhood. The adolescent use literature suggests a marginal (at best) association between acute intoxication and aggressive behavior, and an association between chronic use and aggressive behavior heavily influenced by demographic variables, rather than direct, psychopharmacological mechanisms. Cannabis withdrawal symptoms also may include aggression and anger, but there is little evidence to suggest that these effects are large or specific to withdrawal from marijuana compared to other substances. This review will offer recommendations for clinical care and public policy, as well as important questions for future research.

Maternal age and trajectories of cannabis use

BACKGROUND

Becoming a mother is a developmental transition that has been linked to desistance from substance use. However, timing of motherhood may be a key determinant of cannabis use in women, based on preliminary evidence from teenage mothers. The goal of this study was to identify trajectories of maternal cannabis use, and to determine if maternal age was associated with different trajectories of use.

METHODS

This prospective study examined 456 pregnant women recruited at a prenatal clinic, ranging in age from 13 to 42 years. The women were interviewed about their cannabis use 1 year prior to pregnancy and during each trimester of pregnancy, and at 6, 10, 14, and 16 years post-partum.

RESULTS

A growth mixture model of cannabis use reported at each time point clearly delineated four groups: non/unlikely to use, decreasing likelihood of use, late desistance, and increasing likelihood/chronic use (Lo-Mendell-Rubin adjusted LRT test statistic=35.7, p<.001). The youngest mothers were least likely to be in the "non/unlikely to use" group. Younger maternal age also differentiated between late desistance and increasing likelihood/chronic use, versus decreasing likelihood of use post-partum.

CONCLUSIONS

This is the first study to demonstrate that younger mothers are more likely to use cannabis across 17 years, including later desistance post-partum and increasing/chronic use. Other substance use and chronic depressive symptoms were also associated with more frequent use. These findings have implications for both prevention and treatment of cannabis use in mothers.