Factors associated with variability and stability of cannabis use in young adulthood

Change in marijuana use from adolescence to young adulthood and its relation to gestational alcohol and marijuana exposure

INTRODUCTION

Many studies have examined changes in marijuana use across adolescence, but few have examined factors associated with transitions from adolescence to young adulthood. We examined prenatal exposures to alcohol and marijuana and adolescent risk and protective factors that best distinguished among abstinence, continuity, or cessation of marijuana use from 16 to 22 years.

METHOD

Data were from the Maternal Health Practices and Child Development Project at the prenatal and 16- and 22-year follow-up phases. The offspring were of lower socioeconomic status with an average of 12.8 years of education at 22 years. Participants' frequency and quantity of marijuana use over the past year were used to determine change in use. A discriminant analysis was applied to distinguish among the identified groups. The risk factors considered included prenatal substance exposures and age 16 demographics, behavior, and home environment.

RESULT

Four categories of transitions were defined based on marijuana use from 16 to 22 years: non-users (n = 193), stop/decrease (n = 81), continue at same level/increase (n = 125), and initiation after the 16-year phase (n = 122). The factors that best distinguished among these groups were peers' marijuana use, delinquency, caregivers' financial strain, prenatal exposure to alcohol and marijuana, and race.

CONCLUSION

Prenatal alcohol and marijuana exposure were significantly related to transitions of marijuana use from adolescence to young adulthood, controlling for peers' use, behavior problems, and home environment. While gestational marijuana exposure was associated with early initiation/increasing use, alcohol exposure was related to later initiation. The findings emphasize the long-term effects of prenatal exposure to alcohol and marijuana.

Childhood Religious Affiliation Type Is Associated with Alcohol, but Not Cannabis Use in Adults

With the recent rise in cannabis use and reported association between use and biopsychosocial risk, identifying factors to reduce use is important. This study examined the association between religion and spirituality factors and cannabis initiation and use. An online survey sample (N = 935) provided demographic, childhood religious affiliation (association with a specific religious group), religiosity (e.g., church attendance, prayer), spirituality, and substance use-related information. As hypothesized, participants with higher religiosity scores were less likely to be regular cannabis users (p = .017). However, cannabis use (early initiation, regular use, recent use, problematic use) was not associated with religious affiliation or with religious affiliation type (religions grouped by identifiable characteristics). Nevertheless, religious affiliation type was associated with recent alcohol use (p < .001) and recent intoxication (p = .006) among participants who reported cannabis use at least once, supporting previous research suggesting an inverse relation between religiosity and substance use. Overall, childhood religious affiliation type was not associated with cannabis use milestones as had been previously reported for alcohol use milestones. This suggests important differences between alcohol and cannabis use characteristics (e.g., social acceptability, recreational vs. medicinal substance) that may have implications for future substance use research, prevention, and treatment.

Risk factors for alcohol, marijuana, and cigarette polysubstance use during adolescence and young adulthood: A 7-year longitudinal study of youth at high risk for smoking escalation

INTRODUCTION

Alcohol, nicotine, and marijuana are the three most widely used substances among adolescents and young adults, with co-use of multiple substances being common. Few longitudinal studies have examined risk factors of alcohol, marijuana, and nicotine poly-substance use. We examined frequency of alcohol, marijuana, and cigarette poly-substance use over time and how key risk factors contribute to this substance use during adolescence and young adulthood.

METHODS

Participants (N = 1263 9th and 10th graders) were oversampled for ever-smoking a cigarette at baseline from 16 Chicago-area high schools between 2004 and 2006. Many participants progressed to heavier cigarette use, as well as alcohol and marijuana use over time. Participants completed questionnaires assessing substance use and psychosocial factors at baseline, 6-, 15-, 24-, 33-months, and 5-, 6-, and 7-years.

RESULTS

Longitudinal multi-level models demonstrated that at baseline and over time, more depression symptoms, more anxiety symptoms, negative mood regulation expectancies, and lower grade point average (GPA) were each associated with more poly-substance use over time. In addition, there were a number of interaction effects of gender (e.g., depression was related to substance use in males) and developmental stage moderated these relationships.

CONCLUSIONS

Depression, anxiety, negative mood regulation expectancies, and GPA all significantly influence both initial and longitudinal levels of substance use across adolescence and young adulthood. Our findings underscore the importance of identifying and treating youth with depression and anxiety symptoms, as well as providing resources early for those struggling in school in order to help with substance use prevention and intervention efforts.

Relationships between age at first substance use and persistence of cannabis use and cannabis use disorder

Background

From a secondary prevention perspective, it is useful to know who is at greatest risk of progressing from substance initiation to riskier patterns of future use. Therefore, the aim of this study was to determine relationships between age at first use of alcohol, tobacco and cannabis and patterns of cannabis use, frequency of use and whether age of substance use onset is related to having a cannabis use disorder (CUD).

Methods

We analysed data from Ireland’s 2010/11 and 2014/15 National Drug Prevalence Surveys, which recruited 5134 and 7005 individuals respectively, aged 15 years and over, living in private households. We included only those people who reported lifetime cannabis use. Multinomial, linear and binary logistic regression analyses were used to determine relationships between age of substance use onset and patterns of cannabis use, frequency of use and having a CUD.

Results

When compared to former users, the odds of being a current cannabis user were found to be reduced by 11% (OR = 0.89; 95% CI: 0.83, 0.95) and 4% (OR = 0.96; 95% CI: 0.92, 1.00) for each year of delayed alcohol and cannabis use onset, respectively. Among current users, significant inverse linear relationships were noted, with increasing age of first use of tobacco (β = − 0.547; P < .001) and cannabis (β = − 0.634; P < .001) being associated with a decreased frequency of cannabis use within the last 30 days. The odds of having a CUD were found to be reduced by 14% (OR = 0.86; 95% CI: 0.78, 0.94) and 11% (OR = 0.89; 95% CI: 0.82, 0.98) for each year of delayed tobacco and cannabis use onset respectively in analyses which examined survey participants aged 15–34 years.

Conclusions

Among people who report past cannabis use, it is those with a more precocious pattern of early use of substances, including alcohol, and especially tobacco and cannabis, who are more likely to report ongoing, heavy and problematic cannabis use. Secondary prevention initiatives should prioritise people with a pattern of very early onset substance use.

The Relationship Between Behavioral Inhibition and Approach Motivation Systems (BIS/BAS) and Intrinsic Brain Network Connectivity in Adult Cannabis Users

Dampened behavioral inhibition and overactive behavioral approach motivation systems (i.e. BIS/BAS) are associated with cannabis use disorder (CUD), although the underlying neural mechanisms of these alterations have not yet been examined. The brain’s executive control network (ECN) plays a role in decision-making and is associated with BIS/BAS. In this study, we tested the hypothesis that altered ECN resting-state functional connectivity (rsFC) underlies dysfunctional behavioral inhibition and approach motivation in cannabis users. To that end, we collected resting-state functional magnetic resonance imaging scans in 86 cannabis using adults and 59 non-using adults to examine group differences in the relationship between ECN rsFC and BIS/BAS. Our results showed that BIS was positively correlated with left ECN rsFC in cannabis users, while it was positively correlated with right ECN rsFC in non-users. There was a trend-level moderation effect of group on the association between BIS/BAS and ECN rsFC, showing a weaker association in BIS/BAS and ECN rsFC in cannabis users compared to non-users. An exploratory mediation analysis found that the severity of CUD mediated the relationship between users’ BIS scores and left ECN rsFC. These findings suggest that cannabis use may lead to dysregulation in typical ECN functional organization related to BIS/BAS.

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.

Past-month cannabis use among U.S. individuals from 2002-2015: An age-period-cohort analysis

BACKGROUND

Cannabis is the most commonly used illicit drug among U.S. adolescents and adults, but little is known about factors that drive trends in cannabis use prevalence. To better understand drivers of these trends, we aimed to estimate age, period, and cohort effects on past-month cannabis use among U.S. individuals age 12 and older from 2002 to 2015.

METHODS

We conducted an age-period-cohort analysis on past-month cannabis use among participants ages 12 and older using the National Survey on Drug Use and Health (NSDUH), an annual cross-sectional nationally-representative survey of drug use. Additionally, we examined how age, period, and cohort effects differed across gender. Participants (n = 779,799) self-reported cannabis patterns using a computer-assisted telephone interview (CATI).

RESULTS

Past-month cannabis use in this population increased from 6.0% in 2002 to 8.1% in 2015. Distinct age, period, and cohort effects were observed. Compared to participants ages 12-13, participants ages 18-21 (PR: 16.8, 95% CI: 15.6, 18.1) and 22-25 (PR: 13.2, 95% CI: 12.2, 14.4) had dramatically higher prevalence of past-month cannabis use. Compared to participants in 2002, participants in 2014 (PR: 1.2, 95% CI: 1.1, 1.4) and 2014 (PR: 1.2, 95% CI: 1.1, 1.4) had slightly higher prevalence of past-month cannabis use. Compared to the 1940s birth cohort, the 1950s birth cohort (PR: 1.8, 95% CI: 1.5, 2.2) had a higher prevalence of past-month cannabis use.

CONCLUSIONS

Past-month cannabis use is prevalent and increasing among U.S. adults. Distinct age, period, and cohort effects are at play, though age effects are strongest.

Gender difference in early initiation of methamphetamine use among current methamphetamine users in Muse, Northern Shan State, Myanmar

Background

Globally, methamphetamine (MA) use is a significant public health concern due to unprecedented health effects of its use. However, gender similarities and differences in early age of MA initiation and its risk factors among current MA users have been understudied in a developing country setting.

Methods

A community-based, cross-sectional study was conducted using a computer assisted self-interviewing program from January to March 2013 in Muse, Northern Shan State, Myanmar. A total of 1362 (775 male and 587 female) self-reported current MA users aged between 18 and 35 years were recruited using respondent-driven sampling. Two gender-stratified multiple logistic regression models (models I and II) were done for analysis.

Results

For similarities, 73.0% of males and 60.5% of females initiated MA before their 18th birthday. The early age of MA initiation was positively associated with the reasons and places of the first time MA use among both genders. For differences, males [hazard ratio 1.35; 95% confidence interval, 1.18–1.54] had a significantly higher risk than females to initiate MA at earlier age. Among male users, participants who had bisexual/homosexual preferences were more likely to initiate MA use earlier. In contrast, female users who exchanged sex for money and/or drugs were more likely to initiate MA in earlier age.

Conclusions

More than 60.0% of male and female participants initiated MA use early; however, males initiated use earlier than females. Although similarities were found among both genders, differences found in key risk factors for early age MA initiation suggest that gender-specific, MA prevention programs are urgently needed in Myanmar.

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.

Does Cannabis Cause, Exacerbate or Ameliorate Psychiatric Disorders? An Oversimplified Debate Discussed

There have been extensive policy shifts in the legality of recreational and therapeutic use of cannabis in the United States, as well as a steady increase in the number of people using the drug on a regular basis. Given these rapid societal changes, defining what is known scientifically about the consequences of cannabis use on mental health takes on added public health significance. The purpose of this circumspectives piece is to discuss evidence of cannabis' effects on two psychiatric conditions: post-traumatic stress disorder and psychotic disorders. Dr Haney and Dr Evins will discuss two viewpoints regarding the benefit and harm of cannabis use for these conditions, while outlining what remains unproven and requires further testing to move the field forward.

Gender differences in the associations among marijuana use, cigarette use, and symptoms of depression during adolescence and young adulthood

INTRODUCTION

As prevalence of marijuana use increases, it is important that we better understand how factors like gender, cigarette use, and depression are related to marijuana use during adolescence and young adulthood. We examined longitudinal relationships among these variables in adolescents moving into young adulthood who were studied longitudinally for six years.

METHODS

1263 individuals were included in the study. Participants were oversampled for ever-smoking a cigarette at baseline, when they were 15-16 years old. Frequency of cigarette smoking and marijuana use, as well as depression symptoms, were assessed at baseline, 6, 15, 24, 60 and 72 months.

RESULTS

Cigarette use frequency and depression symptoms were associated with frequency of marijuana use (p-values<.001), particularly in adolescence, but there were important gender differences in these relationships. Specifically, symptoms of depression were related to marijuana use frequency among males (p<.001), but not females (p=.62). In addition, frequency of marijuana use was associated with increased cigarette use frequency, especially among males who had higher symptoms of depression (p<.001). However, this effect was not seen among females. Exploratory analyses suggested that relationships between frequency of use and depression are specific to marijuana, not cigarettes.

CONCLUSIONS

Marijuana use is strongly related to depression symptoms and cigarette use frequency in males, indicating that in males these detrimental factors converge, whereas in females they do not. Gender differences in the factors related to marijuana use may mean that there are different risks for and consequences from use and have implications for prevention and intervention efforts.

Emergence of sex differences in the development of substance use and abuse during adolescence

Substance use and abuse begin during adolescence. Male and female adolescent humans initiate use at comparable rates, but males increase use faster. In adulthood, more men than women use and abuse addictive drugs. However, some women progress more rapidly from initiation of use to entry into treatment. In animal models, adolescent males and females consume addictive drugs similarly. However, reproductively mature females acquire self-administration faster, and in some models, escalate use more. Sex/gender differences exist in neurobiologic factors mediating both reinforcement (dopamine, opioids) and aversiveness (CRF, dynorphin), as well as intrinsic factors (personality, psychiatric co-morbidities) and extrinsic factors (history of abuse, environment especially peers and family) which influence the progression from initial use to abuse. Many of these important differences emerge during adolescence, and are moderated by sexual differentiation of the brain. Estradiol effects which enhance both dopaminergic and CRF-mediated processes contribute to the female vulnerability to substance use and abuse. Testosterone enhances impulsivity and sensation seeking in both males and females. Several protective factors in females also influence initiation and progression of substance use including hormonal changes of pregnancy as well as greater capacity for self-regulation and lower peak levels of impulsivity/sensation seeking. Same sex peers represent a risk factor more for males than females during adolescence, while romantic partners increase risk for women during this developmental epoch. In summary, biologic factors, psychiatric co-morbidities as well as personality and environment present sex/gender-specific risks as adolescents begin to initiate substance use.