Associations of alcohol, nicotine, cannabis, and drug use/dependence with educational attainment: evidence from cotwin-control analyses

IQ in high school as a predictor of midlife alcohol drinking patterns

AIMS

The aim of the present study was to assess the relationship between adolescent IQ and midlife alcohol use and to explore possible mediators of this relationship.

METHODS

Study data were from 6300 men and women who participated in the Wisconsin Longitudinal Study of high-school students graduating in 1957. IQ scores were collected during the participants' junior year of high school. In 2004, participants reported the number of alcoholic beverages consumed (past 30 days) and the number of binge-drinking episodes. A multinomial logistic regression was conducted to determine the relationship between adolescent IQ and future drinking pattern (abstainer, moderate drinker, or heavy drinker), and Poisson regression was used to examine the number of binge-drinking episodes. Two mediators-income and education-were also explored.

RESULTS

Every one-point increase in IQ score was associated with a 1.6% increase in the likelihood of reporting moderate or heavy drinking as compared to abstinence. Those with higher IQ scores also had significantly fewer binge-drinking episodes. Household income, but not education, partially mediated the relationship between IQ and drinking pattern.

CONCLUSIONS

The present study suggests that higher adolescent IQ may predict a higher likelihood of moderate or heavy drinking in midlife, but fewer binge-drinking episodes. The study also suggests that this relationship is mediated by other psychosocial factors, specifically income, prompting future exploration of mediators in subsequent studies.

The impact of recreational cannabis legalization on youth: the Colorado experience

Over the past two decades, cannabis policies have liberalized in the United States, culminating in the legalization of recreational cannabis in Colorado and Washington state in 2012. This review will focus on the impact of recreational cannabis legalization in Colorado. While the prevalence of past-year and past-month cannabis use has remained relatively steady among adolescents post-legalization, the prevalence of young adult use has continued to rise. Cannabis products with increased potency have become more prevalent and widely used. There are concerns that the use of products with increased potency will increase risk for cannabis use and comorbid mental health disorders, particularly cannabis-induced psychosis and suicidal behavior, although more research is needed to fully understand the impact of high-potency products. Since the legalization of recreational cannabis, numerous additional public health concerns have emerged: unintentional overdoses requiring acute care visits, electronic vaping-associated lung injury, increased motor vehicle collisions related to cannabis consumption, and higher rates of cannabis use during pregnancy. Lessons learned from the first decade of cannabis legalization emphasize the need for research efforts to provide evidence-based guidelines, inform prevention strategies, and implement selective interventions for at-risk populations including youth, individuals with comorbid mental health disorders, and individuals who are pregnant.

Genetic and shared environmental factors explain the association between adolescent polysubstance use and high school noncompletion

OBJECTIVE

Examine the nature of the relationship between adolescent polysubstance use and high school noncompletion.

METHOD

Among a sample of 9,579 adult Australian twins (58.63% female, Mage = 30.59), we examined the association between the number of substances used in adolescence and high school noncompletion within a discordant twin design and bivariate twin analysis.

RESULTS

In individual-level models controlling for parental education, conduct disorder symptoms, childhood major depression, sex, zygosity, and cohort, each additional substance used in adolescence was associated with a 30% increase in the odds of high school noncompletion (OR = 1.30 [1.18, 1.42]). Discordant twin models found that the potentially causal effect of adolescent use on high school noncompletion was nonsignificant (OR = 1.19 [0.96, 1.47]). Follow-up bivariate twin models suggested genetic (35.4%, 95% CI [24.5%, 48.7%]) and shared environmental influences (27.8%, 95% CI [12.7%, 35.1%]) each contributed to the covariation in adolescent polysubstance use and early school dropout.

CONCLUSIONS

The association between polysubstance use and early school dropout was largely accounted for by genetic and shared environmental factors, with nonsignificant evidence for a potentially causal association. Future research should examine whether underlying shared risk factors reflect a general propensity for addiction, a broader externalizing liability, or a combination of the two. More evidence using finer measurement of substance use is needed to rule out a causal association between adolescent polysubstance use and high school noncompletion. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Prospective associations between adolescent risky substance use and school dropout and the role of externalising and internalising problems

Background: The aim of the present study was to assess to what extent risky substance use (RSU) acts as an important risk factor for school dropout from upper secondary school in a prospective study of Norwegian adolescents, and how externalising and internalising mental health problems influenced this association. Methods: We used data from a large population-based survey (the youth@hordaland-survey), which included adolescents aged 16-19 years. The predictor variables were self-reported RSU. The survey was linked with prospective data from the Norwegian Education Database, following the adolescents to 21-23 years of age. The outcome variable was registry-based school dropout within five years after starting upper secondary school. The analyses were adjusted for sex, age, socioeconomic status, and externalising and internalising problems. Results: After adjustment for sociodemographic variables, all indicators of RSU were prospectively associated with school dropout (adjusted odds ratios 1.26-2.25; all p values <.01). While internalising problems only slightly changed these estimates, the associations were substantially attenuated by externalising problems. Still, all measures of RSU, except frequent alcohol intoxication, remained positively associated with school dropout in the fully adjusted models. For the youngest students, all associations between RSU and school dropout were significant. Conclusions: Adolescent RSU is a strong predictor for school dropout, and externalising problems explained a considerable proportion of this effect. Prevention efforts to reduce student substance could improve academic outcomes among upper secondary school students, and such efforts may benefit from also targeting co-occurring externalising problems.

Risk of suicidal behavior as a function of alcohol use disorder typologies: A Swedish population-based study

BACKGROUND AND AIMS

Alcohol use disorder (AUD) is one of the strongest predictors of suicidal behavior. Here, we measured risk of suicide attempt and death as a function of AUD typologies.

DESIGN

We used AUD typologies from previous latent class analysis: (i) externalizing subtype (characterized by externalizing symptomatology and early age of onset; individuals in this group have lower education and higher familial/social difficulties); (ii) subtype described by minimal psychopathology; and (iii) internalizing subtype (characterized by internalizing symptomatology and later age of onset; individuals in this group have higher education). We used class membership to predict distal outcomes (attempt and death) and performed regressions to evaluate whether differences in suicidal behavior were explained by the group characteristics (sex, age of onset, number and type of AUD registrations, familial/genetic risk for AUD, externalizing and internalizing behaviors, socio-economic indicators, marital status and childhood family status). We also evaluated the effect of suicide attempt prior to AUD.

SETTING AND PARTICIPANTS

Based on longitudinal Swedish registry data, we included 217 074 individuals with AUD born 1950-80.

MEASUREMENTS

Suicide attempts were identified using medical registers and deaths using the mortality register.

FINDINGS

Individuals with the externalizing subtype had higher risks of suicidal behavior than other groups [attempt: externalizing versus minimal psychopathology: odds ratio (OR) = 1.35, 95% confidence interval (CI) = 1.35, 1.35; externalizing versus internalizing: OR = 1.47, 95% CI = 1.46, 1.48; death: externalizing versus minimal psychopathology: OR = 1.57, 95% CI = 1.57, 1.58; externalizing versus internalizing: OR = 1.99, 95% CI = 1.93, 2.06]. Individuals with minimal psychopathology had higher risks than those with internalizing symptomatology (attempt: OR = 1.09, 95% CI = 1.08, 1.10, death: OR = 1.26, 95% CI = 1.23, 1.30). These differences were explained by age at registration and were related to the number of registrations, sex, education, family disruption and suicide attempt prior to AUD.

CONCLUSIONS

Among people in Sweden, considering alcohol use disorder (AUD) heterogeneity appears to be a meaningful way to evaluate suicide risk. The highest risk of suicide attempt and death occurs in the externalizing subtype of AUD, followed by the minimal psychopathology subtype, and then the internalizing subtype.

Substance Use and Educational Impacts in Youth With and Without Chronic Illness

INTRODUCTION

Alcohol, cannabis, and nicotine are commonly used psychoactive substances that affect adolescent neurocognition. Little is known about the educational impacts of their use on measures of educational performance, participation and problems, especially among youth with a chronic illness who may use these substances to alleviate stress and symptoms.

METHODS

Adolescents receiving general or subspecialty care were administered an electronic survey from 2016 to 2018. Data were analyzed in 2023. Using modified Poisson models, cross-sectional associations between past 12-month usage of alcohol, cannabis, and/or nicotine and educational impacts were estimated.

RESULTS

Among 958 adolescents (mean age 16.0 years (SD 1.3), 564 (58.9%) female gender, 445 (46.5%) in subspecialty care), 294 (30.7%), 220 (23.0%), and 126 (13.2%) reported past 12-month use of alcohol, cannabis, and nicotine respectively, while 407 (42.5%) reported ≥1 educational impact, including recent lower grades 210 (21.9%), past 3-month truancy from school 164 (17.1%) or activities 170 (17.7%), and detention 82 (8.6%). Use of cannabis, but not other substances, was associated with negative educational impacts: lower grades (mostly C's/D's/F's), adjusted prevalence ratios [APR, (95% CI)] 1.54 (1.13-2.11); past 3-month truancy from school [2.16 (1.52-3.07)]; detention [2.29 (1.33-3.94)]. The association between cannabis use and any negative educational impact was stronger among adolescents with a chronic illness (p<0.001).

CONCLUSIONS

Among adolescents, cannabis use was associated with a heightened risk of negative educational impacts, even after controlling for alcohol and nicotine use. Adolescents with chronic illness were especially likely to experience negative educational impacts. Findings underscore need for preventive interventions and messaging to reduce risks.

Unraveling shared susceptibility loci and Mendelian genetic associations linking educational attainment with multiple neuropsychiatric disorders

Background

Empirical studies have demonstrated that educational attainment (EA) is associated with neuropsychiatric disorders (NPDs), suggesting a shared etiological basis between them. However, little is known about the shared genetic mechanisms and causality behind such associations.

Methods

This study explored the shared genetic basis and causal relationships between EA and NPDs using the high-definition likelihood (HDL) method, cross phenotype association study (CPASSOC), transcriptome-wide association study (TWAS), and bidirectional Mendelian randomization (MR) with summary-level data for EA (N = 293,723) and NPDs (N range = 9,725 to 455,258).

Results

Significant genetic correlations between EA and 12 NPDs (rg range - 0.49 to 0.35; all p < 3.85 × 10-3) were observed. CPASSOC identified 37 independent loci shared between EA and NPDs, one of which was novel (rs71351952, mapped gene: ARFGEF2). Functional analyses and TWAS found shared genes were enriched in brain tissue, especially in the cerebellum and highlighted the regulatory role of neuronal signaling, purine nucleotide metabolic process, and cAMP-mediated signaling pathways. CPASSOC and TWAS supported the role of three regions of 6q16.1, 3p21.31, and 17q21.31 might account for the shared causes between EA and NPDs. MR confirmed higher genetically predicted EA lower the risk of ADHD (ORIVW: 0.50; 95% CI: 0.39 to 0.63) and genetically predicted ADHD decreased the risk of EA (Causal effect: -2.8 months; 95% CI: -3.9 to -1.8).

Conclusion

These findings provided evidence of shared genetics and causation between EA and NPDs, advanced our understanding of EA, and implicated potential biological pathways that might underlie both EA and NPDs.

Limited psychological and social effects of lifetime cannabis use frequency: Evidence from a 30-year community study of 4,078 twins

BACKGROUND

Cannabis use is associated with outcomes like income, legal problems, and psychopathology. This finding rests largely on correlational research designs, which rely at best on statistical controls for confounding. Here, we control for unmeasured confounders using a longitudinal study of twins.

METHOD

In a sample of 4,078 American adult twins first assessed decades ago, we used cotwin control mixed effects models to evaluate the effect of lifetime average frequency of cannabis consumption measured on substance use, psychiatric, and psychosocial outcomes.

RESULTS

On average, participants had a lifetime cannabis frequency of about one to two times per month, across adolescence and adulthood. As expected, in individual-level analyses, cannabis use was significantly associated with almost all outcomes in the expected directions. However, when comparing each twin to their cotwin, which inherently controls for shared genes and environments, we observed within-pair differences consistent with possible causality in three of the 22 assessed outcomes: cannabis use disorder symptoms (βW-Pooled = .15, SE = .02, p = 1.7 × 10-22), frequency of tobacco use (βW-Pooled = .06, SE = .01, p = 1.2 × 10-5), and illicit drug involvement (βW-Pooled = .06, SE = .02, p = 1.2 × 10-4). Covariate specification curve analyses indicated that within-pair effects on tobacco and illicit drug use, but not cannabis use disorder, attenuated substantially when covarying for lifetime alcohol and tobacco use.

CONCLUSIONS

The cotwin control results suggest that more frequent cannabis use causes small increases in cannabis use disorder symptoms, approximately 1.3 symptoms when going from a once-a-year use to daily use. For other outcomes, our results are more consistent with familial confounding, at least in this community population of twins. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Alcohol use and treatment utilization in a national sample of veterans and nonveterans

BACKGROUND

Research comparing prevalence of alcohol use problems and alcohol treatment utilization between veterans and nonveterans is lacking. Whether predictors of alcohol use problems and alcohol treatment utilization differ in veterans vs. nonveterans is also unclear.

METHODS

Using survey data from national samples of post-9/11 veterans and nonveterans (N = 17,298; 13,451 veterans, 3847 nonveterans), we investigated associations between veteran status and 1) alcohol consumption, 2) need for intensive alcohol treatment, and 3) past-year and lifetime alcohol treatment utilization. We also investigated associations between predictors and these three outcomes in separate models for veterans and nonveterans. Predictors included age, gender, racial/ethnic identity, sexual orientation, marital status, education, health coverage, financial difficulty, social support, adverse childhood experiences (ACEs), and adult sexual trauma.

RESULTS

Population weighted regression models demonstrated that veterans reported modestly higher alcohol consumption than nonveterans, but were not significantly more likely to need intensive alcohol treatment. Veterans and nonveterans did not differ in past-year alcohol treatment utilization, but veterans were 2.8 times more likely to utilize lifetime treatment than nonveterans. We found several differences between veterans and nonveterans in associations between predictors and outcomes. For veterans, being male, having higher financial difficulty, and lower social support were associated with need for intensive treatment, but for nonveterans, only ACEs were associated with need for intensive treatment.

CONCLUSIONS

Veterans may benefit from interventions with social and financial support to reduce alcohol problems. These findings can help to identify veterans and nonveterans who are more likely to need treatment.

Adolescent substance use and high school noncompletion: exploring the nature of the relationship using a discordant twin design

BACKGROUND AND AIMS

Previous studies have demonstrated associations between substance use and reduced educational attainment; however, many were unable to account for potential confounding factors like genetics and the rearing environment. In the few studies that controlled for these factors, the substances assessed were limited to alcohol, cannabis, and tobacco. To address these limitations, we examined the relationship between adolescent use of seven kinds of substances, the number of additional substances used, and high school noncompletion within a large sample of Australian twins.

DESIGN

A series of two-level generalized mixed effects logistic regressions were conducted to examine associations between adolescent substance use and high school noncompletion.

SETTING

Australia.

PARTICIPANTS

A total of 9579 adult Australian twins from two cohorts of the Australian Twin Registry.

MEASUREMENTS

Assessments of high school completion, childhood major depression, conduct disorder symptoms, substance use initiation, demographics, and parental educational attainment using the Australian version of the Semi-Structured Assessment for the Genetics of Alcoholism.

FINDINGS

There were unique within-twin-pair effects of use of sedatives (odds ratio [OR] = 22.39 [95% confidence interval (CI) = 1.18-423.48]) and inhalants/solvents (OR = 10.46 [95% CI = 1.30-84.16]) on high school noncompletion. The number of substances used in adolescence was strongly associated with high school noncompletion across all discordant twin models (ORs from 1.50-2.32, Ps < 0.03).

CONCLUSIONS

In Australia, adolescent substance use appears to be associated with early school dropout, with the effects of any given substance largely because of the confounding factors of parental education, childhood conduct disorder symptoms, and use of other substances. Sedatives and inhalants/solvents have effects on high school noncompletion that cannot be explained by polysubstance use or familial factors.

Educational Attainment Polygenic Scores: Examining Evidence for Gene-Environment Interplay with Adolescent Alcohol, Tobacco and Cannabis Use

Genes associated with educational attainment may be related to or interact with adolescent alcohol, tobacco and cannabis use. Potential gene-environment interplay between educational attainment polygenic scores (EA-PGS) and adolescent alcohol, tobacco, and cannabis use was evaluated with a series of regression models fitted to data from a sample of 1871 adult Australian twins. All models controlled for age, age², cohort, sex and genetic ancestry as fixed effects, and a genetic relatedness matrix was included as a random effect. Although there was no evidence that adolescent alcohol, tobacco or cannabis use interacted with EA-PGS to influence educational attainment, there was a significant, positive gene-environment correlation with adolescent alcohol use at all PGS thresholds (ps <.02). Higher EA-PGS were associated with an increased likelihood of using alcohol as an adolescent (ΔR² ranged from 0.5% to 1.1%). The positive gene-environment correlation suggests a complex relationship between educational attainment and alcohol use that is due to common genetic factors.

Diagnostic remission of substance use disorders: Racial differences and correlates of remission in a nationally representative sample

INTRODUCTION

Research has shown racial/ethnic minorities to have similar risk of developing substance use disorders (SUDs) as Whites. However, few studies have compared the likelihood of diagnostic remission (i.e., no longer meeting criteria for current SUDs).

METHODS

Using nationally representative survey data from the National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III), we examined all adults with lifetime SUDs; compared the proportions experiencing diagnostic remission; and used logistic regression analyses to compare Black, Hispanic, and other racial/ethnic minorities to Whites. The research team initially used bivariate comparisons to identify potentially confounding factors also associated with remission. The study used multivariable-adjusted logistic regression analyses to adjust for these potentially confounding covariates. The team conducted separate analyses for alcohol use disorder (AUD) and drug use disorders (DUDs).

RESULTS

Of 10,916 individuals with lifetime SUDs, 5120 no longer met criteria for an SUD in the past year (55.2% of White, 34.0% of Black, 38.5% Hispanic, and 40.1% of other individuals). In unadjusted analyses, Black, Hispanic, and others were significantly and about half as likely as Whites to have remitted with odds ratios (ORs) of 0.42 (95% CI 0.36-0.48), 0.51 (0.45-0.58), and 0.55 (0.45-0.65), respectively. The study found similar results for both AUD and DUDs. Adjusting for potentially confounding factors only modestly improved the likelihood of remission among racial/ethnic minorities compared to White individuals.

CONCLUSION

Minority race/ethnicity is robustly associated with reduced likelihood of diagnostic remission from SUDs even after adjusting for other factors. This study could identify only partial moderators of these disparities; these moderators deserve further study.

Educational inequalities in mental disorders in the Czech Republic: data from CZEch Mental health Study (CZEMS)

PURPOSE

We aimed to study the association of educational attainment with occurrence of mental disorders in the Czech Republic.

METHODS

Data were derived from the CZEch Mental health Study (CZEMS), a cross-sectional study of community-dwelling individuals. Mental disorders were assessed with Mini International Neuropsychiatric Interview (M.I.N.I.), and information on completed education was acquired as a part of a paper and pencil interview. Logistic regression was used to estimate odds ratio (OR) with 95% confidence intervals (CI) for the association of educational attainment with all mental disorders as well as with specific groups (affective, anxiety, alcohol use and substance use disorders), stepwise adjusting for socio-demographic, social and health-related characteristics.

RESULTS

We studied 3175 individuals (average age 50 years, range 18-96 years; 54% women). Compared to individuals with higher education, those educated below high school graduation had higher odds of mental disorders (OR 2.07; 95% CI 1.58-1.71), even after adjustment for all covariates (OR 1.64; 95% CI 1.21-2.23). Education showed the strongest association with alcohol use disorders, even when covariates were adjusted for, but was not related to anxiety disorders. The association of education with affective as well as substance use disorders was explained by covariates.

CONCLUSIONS

Interventions aimed at reducing the burden of mental disorders should target individuals with low education. Strategies to improve population mental health need to go hand in hand with policies to enhance education as well as reduce alcohol consumption in the Czech Republic.

Cannabis use among military veterans: A great deal to gain or lose?

Policy changes have resulted in dramatic increases in access to cannabis for medical purposes. Veterans are disproportionately affected by conditions for which medical cannabis is often pursued, making an evidence-based perspective on risks versus benefits of high priority. The current review sought to examine the state of the evidence on the correlates and consequences of cannabis use among veterans. Using a comprehensive search strategy, 501 articles were identified and 86 studies met criteria for inclusion. The literature was predominated by cross-sectional studies (67%) of male veterans (71.4%-100% male) from the United States (93.0%). Three overarching themes emerged, comprising cannabis associations with other substance use, mental health, and physical health outcomes. The balance of the evidence associated cannabis use with negative health outcomes, with consistent positive associations with other substance use, psychiatric disorders, and self-harm/suicidality. Few studies examined the therapeutic effects of cannabis, thus limiting the potential to evaluate evidence of efficacy. Priority areas for future research are studies using designs that can examine the directionality of links between cannabis and health in veterans more conclusively, and studies directly examining therapeutic efficacy of cannabis-based therapies in veterans. Methodologically rigorous design will be essential to inform clinical recommendations and practices guidelines in an era of burgeoning access to cannabis.

Adolescent cannabis use, cognition, brain health and educational outcomes: A review of the evidence

We review the findings of systematic reviews and meta-analyses of case-control studies that examine brain functioning and cognitive correlates of adolescent cannabis use using structural and functional neuroimaging tools and standardised neuropsychological tests. We also examine prospective epidemiological studies on the possible effects of adolescent and young adult cannabis use on cognitive performance in adult life and the completion of secondary education. We summarize the findings of studies in each of these areas that have been published since the most recent systematic review. Systematic reviews find that adolescent cannabis use is inconsistently associated with alterations in the structure of prefrontal and temporal brain regions. Meta-analyses reveal functional alterations in the parietal cortex and putamen. Differences in the orbitofrontal cortex predate cannabis use; it is unclear if they are affected by continued cannabis use and prolonged abstinence. Longitudinal and twin studies report larger declines in IQ among cannabis users than their non-using peers but it is unclear whether these findings can be attributed to cannabis use or to genetic, mental health and environmental factors. Several longitudinal studies and a meta-analysis of cross-sectional studies suggest that there is some cognitive recovery after abstinence from cannabis. Longitudinal studies and some twin studies have found that cannabis users are less likely to complete secondary school than their non-using controls. This association might reflect an effect of cannabis use and/or the social environment of cannabis users and their cannabis using peers. Cognitive performance is altered in some domains (e.g. IQ, verbal learning) in young people while they are regularly using cannabis. There are two important messages to adolescents and young adults: First, cannabis has potentially detrimental effects on cognition, brain and educational outcomes that persist beyond acute intoxication. Second, impaired cognitive function in cannabis users appears to improve with sustained abstinence.

Profiles of Psychosocial Risk and Protective Factors and their Associations with Alcohol Use and Regular Smoking in Black Adults

INTRODUCTION

This study aimed to identify the clustering of substance use-related psychosocial risk and protective factors (subgroups) and the differential associations of those subgroups with current alcohol use and regular smoking among Black adults.

METHODS

Data were drawn from 4462 participants (29% Afro Caribbean, 71% African American; median age = 38; 63% female) in a nationally representative study of social, economic, and structural conditions and health in Black Americans. Latent classes, i.e., subgroups, were derived via latent profile analysis with 10 indicators representing social support and religious involvement (support); demands from family and religious community (demands); and socioeconomic and neighborhood factors and racial discrimination (adversity). Frequency of alcohol use and prevalence of regular smoking were compared across classes using regression analyses.

RESULTS

Four classes emerged: (1) high support, low demands and adversity; (2) high support and demands, low-moderate adversity; (3) low support and demands, low-moderate adversity; and (4) low support, high demands and adversity. Relative to Class 1, frequency of alcohol use and regular smoking prevalence were significantly higher only in Class 4.

CONCLUSIONS

Results indicate substantive variations in the clustering of substance use-related psychosocial risk and protective factors in Black adults. Furthermore, they suggest that neither the presence of high demands nor the absence of support alone differentiates likelihood of engaging in frequent alcohol use or regular smoking, but adverse experiences such as racial discrimination may be especially impactful.

Sibling comparisons elucidate the associations between educational attainment polygenic scores and alcohol, nicotine and cannabis

BACKGROUND AND AIMS

The associations between low educational attainment and substance use disorders (SUDs) may be related to a common genetic vulnerability. We aimed to elucidate the associations between polygenic scores for educational attainment and clinical criterion counts for three SUDs (alcohol, nicotine and cannabis).

DESIGN

Polygenic association and sibling comparison methods. The latter strengthens inferences in observational research by controlling for confounding factors that differ between families.

SETTING

Six sites in the United States.

PARTICIPANTS

European ancestry participants aged 25 years and older from the Collaborative Study on the Genetics of Alcoholism (COGA). Polygenic association analyses included 5582 (54% female) participants. Sibling comparisons included 3098 (52% female) participants from 1226 sibling groups nested within the overall sample.

MEASUREMENTS

Outcomes included criterion counts for DSM-5 alcohol use disorder (AUDSX), Fagerström nicotine dependence (NDSX) and DSM-5 cannabis use disorder (CUDSX). We derived polygenic scores for educational attainment (EduYears-GPS) using summary statistics from a large (> 1 million) genome-wide association study of educational attainment.

FINDINGS

In polygenic association analyses, higher EduYears-GPS predicted lower AUDSX, NDSX and CUDSX [P < 0.01, effect sizes (R2 ) ranging from 0.30 to 1.84%]. These effects were robust in sibling comparisons, where sibling differences in EduYears-GPS predicted all three SUDs (P < 0.05, R2 0.13-0.20%).

CONCLUSIONS

Individuals who carry more alleles associated with educational attainment tend to meet fewer clinical criteria for alcohol, nicotine and cannabis use disorders, and these effects are robust to rigorous controls for potentially confounding factors that differ between families (e.g. socio-economic status, urban-rural residency and parental education).

Reasons for non-medical use of prescription opioids among young adults: Role of educational status

Non-medical use of prescription opioids (NMUPO) and related overdoses are disproportionately elevated among young adults. Efforts to understand the underlying reasons for NMUPO are critical for developing more effective prevention and intervention strategies for this group. Given the robust literature on the association between educational status and substance abuse risk, we examined the reasons for NMUPO through the lens of educational attainment among young adults. Data from the 2016 National Survey on Drug Use and Health came from an unweighted sample of 941 young adults aged 18-25 years who reported past-year NMUPO. Self-reported reasons for most recent NMUPO were compared by educational status. The most commonly-endorsed reasons for past-year NMUPO was physical pain relief (47.6%), followed by feel good/get high (19.8%), relax/relieve tension (13.2%) and experiment/see what it feels like (6.8%). Reasons for NMUPO did not differ as a function educational status (p = 0.17). These findings suggest that efforts to prevent and address opioid misuse among young adults should focus on understanding and improving pain management in this vulnerable population.

The neurobiology of addiction

Substance and alcohol use disorders impose large health and economic burdens on individuals, families, communities, and society. Neither prevention nor treatment efforts are effective in all individuals. Results are often modest. Advances in neuroscience and addiction research have helped to describe the neurobiological changes that occur when a person transitions from recreational substance use to a substance use disorder or addiction. Understanding both the drivers and consequences of substance use in vulnerable populations, including those whose brains are still maturing, has revealed behavioral and biological characteristics that can increase risks of addiction. These findings are particularly timely, as law- and policymakers are tasked to reverse the ongoing opioid epidemic, as more states legalize marijuana, as new products including electronic cigarettes and newly designed abused substances enter the legal and illegal markets, and as "deaths of despair" from alcohol and drug misuse continue.

Alcohol consumption analysis among patients with liver disease in China

Background:

Alcohol consumption has been observed to be a contributing factor in liver damage. However, very few studies have tried to decipher the correlation between patients with liver disease and alcohol consumption. Therefore, this study was planned to determine the prevalence of alcohol consumption among patients with liver disease, and to evaluate the risk factors, liver diseases, and chronic medical conditions associated with alcohol drinking.

Methods:

A cross-sectional study was conducted among patients with liver disease in 30 provinces, autonomous regions, and municipalities across China. All participants answered the questionnaire, which led to the calculation of Alcohol Use Disorders Inventory Test (AUDIT) score for each patient. Based on this score, low-risk drinkers, hazardous drinkers, and harmful drinkers were defined as having AUDIT score of <8, between 8 and 15, and ≥16, respectively.

Results:

A total of 1489 participants completed the questionnaire. Based on this information, 900 (60.44%) participants were classified as alcohol drinkers. Among these, 8.66% were ex-drinkers, 22.10% were low-risk drinkers, 17.13% were hazardous drinkers, and 12.56% were harmful drinkers. Further investigation of the association between alcohol consumption and other baseline characteristics of patients with liver disease revealed that usually men <40 years old, participants having higher family annual income, having college degree or higher education, living alone, having higher body mass index (BMI), current smokers, and ex-smokers had significant association with higher risk of alcohol consumption. In addition, among the 18.07% of the participants with cirrhosis, it was observed that risk of cirrhosis increased with higher alcohol consumption. Furthermore, harmful drinkers showed greater odds of hypertension and heart diseases, while hazardous drinkers and harmful drinkers, both had greater odds of hyperlipidemia.

Conclusions:

Overall our analyses indicated that among the patients with liver disease in China, there was high rate of alcohol consumption and dependence. Alcohol consumption usually associated with men <40 years old, higher family income, education level, living alone, high BMI, and smoking. Increased alcohol consumption not only increased the risk of cirrhosis, but also enhanced the risk of hypertension, heart diseases, and hyperlipidemia.

Addressing Opioid-Related Chemical Coping in Long-Term Opioid Therapy for Chronic Noncancer Pain: A Multicenter, Observational, Cross-Sectional Study

Opioid consumption has increased worldwide, which carries the risk of opioid use disorder (OUD). However, the literature on OUD and opioid-related chemical coping (OrCC) in chronic noncancer pain (CNCP) is heterogeneous, with most studies conducted in the United States. We performed a multicenter, observational, cross-sectional study to address OrCC in long-term opioid therapy (LtOT) for CNCP in South Korea. The objectives were to determine the frequency and predictors of OrCC. We included 258 patients. Among them, fifty-five (21%) patients showed OrCC. The sample had high pain catastrophizing (≥30 points; 66%), moderate-severe insomnia (≥15 points; 63%), low resilience (68 points), and high suicidal ideation (67%). OrCC patients had greater pain interference (85.18% vs. 58.28%, p = 0.017) and lower satisfaction with the LtOT (56.4% vs. 78.3%, p = 0.002). In multivariable analysis, alcohol abuse (OR = 6.84, p = 0.001), prescription drugs abuse (OR = 19.32, p = 0.016), functional pain (OR = 12.96, p < 0.001), head and neck pain (OR = 2.48, p = 0.039), MEDD (morphine equivalent daily dose) ≥ 200 mg/day (OR = 3.48, p = 0.006), and ongoing litigation (OR = 2.33, p = 0.047) were significant predictors of OrCC. In conclusion, the break-out of OrCC in CNCP in South Korea was comparable to those in countries with high opioid consumption, such as the United States, regardless of the country's opioid consumption rate.

Effect of multiple risk behaviours in adolescence on educational attainment at age 16 years: a UK birth cohort study

OBJECTIVES

To explore the association between adolescent multiple risk behaviours (MRBs) and educational attainment.

DESIGN

Prospective population-based UK birth cohort study.

SETTING

Avon Longitudinal Study of Parents and Children (ALSPAC), a UK birth cohort of children born in 1991-1992.

PARTICIPANTS

Data on some or all MRB measures were available for 5401 ALSPAC participants who attended a clinic at age 15 years and/or completed a detailed questionnaire at age 16 years. Multiple imputation was used to account for missing data.

PRIMARY OUTCOME MEASURES

Capped General Certificate of Secondary Education (GCSE) score and odds of attaining five or more GCSE examinations at grades A*-C. Both outcome measures come from the National Pupil Database and were linked to the ALSPAC data.

RESULTS

Engagement in MRB was strongly associated with poorer educational attainment. Each additional risk equated to -6.31 (95% CI -7.03 to -5.58, p<0.001) in capped GCSE score, equivalent to a one grade reduction or reduced odds of attaining five or more A*-C grades of 23% (OR 0.77, 95% CI 0.74 to 0.81, p<0.001). The average cohort member engaged in 3.24 MRB and therefore have an associated reduction in GCSE score equivalent to three and a half grades in one examination, or reduced odds of attaining five or more A*-C grades of 75%.

CONCLUSION

Engagement in adolescent MRB is strongly associated with poorer educational attainment at 16 years. Preventing MRB could improve educational attainment and thereby directly and indirectly improve longer-term health.

A Co-Twin Control Study of the Relationship Between Adolescent Drinking and Adult Outcomes

OBJECTIVE

The effect of drinking during adolescence on adult functioning is a public health concern. A variety of mechanisms have been proposed where drinking in adolescence has an adverse impact on later outcomes; unfortunately, few studies have included methodologies that account for confounding influences that might link adolescent drinking with subsequent problems. To address this limitation, the current study used a co-twin control design, which uses members of twin pairs that differ from each other on their adolescent drinking.

METHOD

We used a prospective longitudinal sample drawn from the Minnesota Twin Family Study, consisting of 2,764 twins (1,434 female) assessed at regular follow-ups from age 17 to age 29. Adolescent drinking was defined by measures of early initiation of use and a measure of overall consumption at age 17. Adult outcomes included indicators of substance use, antisocial behavior, personality, socioeconomic status, and social functioning.

RESULTS

The co-twin control analyses suggested that many of the associations between adolescent drinking and later outcomes were largely influenced by genetic confounding. However, for the measure of adolescent alcohol consumption, results were consistent with a small causal impact of drinking on multiple domains of adult functioning. This pattern was less consistently observed for the measures of early initiation.

CONCLUSIONS

These results provide empirical justification for policies designed to alleviate long-term consequences associated with adolescent drinking by reducing the level of alcohol consumption in adolescence. In contrast, the evidence did not suggest that delaying drinking would have a broad impact on later-life adjustment.

Inequities in coverage of smokefree outdoor space policies within the United States: school grounds and playgrounds

Background

Previous studies have found extensive geographic and demographic differences in tobacco use. These differences have been found to be reduced by effective public policies, including banning smoking in public spaces. Smokefree outdoor spaces reduce secondhand smoke exposure and de-normalize smoking.

Methods

After previously publishing a study of smokefree indoor and outdoor space policies, it was brought to the authors’ attention that the dataset used in analyses was incomplete (Lowrie et al., BMC Public Health 17:456, 2017). The current manuscript is a corrected version. Here, we include analyses for outdoor space policies. We evaluated regional and demographic differences in the proportion of the population (both adult and child) covered by smokefree outdoor space policies for school grounds and playgrounds enacted in the United States prior to 2014.

Results

Children had a low level of protection in playgrounds and schools (8% covered nationwide in both settings). Significant differences in coverage were found by ethnicity, region, income, and education (p < 0.001). The odds of having a smokefree playgrounds policy was lower for jurisdictions with higher proportions of poor households, households with no high school diploma, whites and the Alaska/Hawaii region. Increased ethnic heterogeneity was found to be a significant predictor of increased odds of having a smokefree playgrounds policy, meaning that diversity is protective, with differential effect by region (p < 0.001) – which may relate to urbanicity.

Conclusions

Disparities in smokefree outdoor space policies have potential to exacerbate existing health inequities. A national increase in smokefree outdoor space policies to protect children in playgrounds and schools is a crucial intervention to reduce such inequities.

Associations of parental alcohol use disorders and parental separation with offspring initiation of alcohol, cigarette and cannabis use and sexual debut in high-risk families

BACKGROUND AND AIMS

Parental alcohol use disorders (AUDs) and parental separation are associated with increased risk for early use of alcohol in offspring, but whether they increase risks for early use of other substances and for early sexual debut is under-studied. We focused on associations of parental AUDs and parental separation with substance initiation and sexual debut to (1) test the strength of the associations of parental AUDs and parental separation with time to initiation (age in years) of alcohol, tobacco and cannabis use and sexual debut and (2) compare the strength of association of parental AUD and parental separation with initiation.

DESIGN

Prospective adolescent and young adult cohort of a high-risk family study, the Collaborative Study on the Genetics of Alcoholism (COGA).

SETTING

Six sites in the United States.

PARTICIPANTS

A total of 3257 offspring (aged 14-33 years) first assessed in 2004 and sought for interview approximately every 2 years thereafter; 1945 (59.7%) offspring had a parent with an AUD.

MEASUREMENTS

Diagnostic interview data on offspring substance use and sexual debut were based on first report of these experiences. Parental life-time AUD was based on their own self-report when parents were interviewed (1991-2005) for most parents, or on offspring and other family member reports for parents who were not interviewed. Parental separation was based on offspring reports of not living with both biological parents most of the time between ages 12 and 17 years.

FINDINGS

Parental AUDs were associated with increased hazards for all outcomes, with cumulative hazards ranging from 1.19 to 2.71. Parental separation was also an independent and consistent predictor of early substance use and sexual debut, with hazards ranging from 1.19 to 2.34. The strength of association of parental separation with substance initiation was equal to that of having two AUD-affected parents, and its association with sexual debut was stronger than the association of parental AUD in one or both parents.

CONCLUSIONS

Parental alcohol use disorders (AUDs) and parental separation are independent and consistent predictors of increased risk for early alcohol, tobacco and cannabis use and sexual debut in offspring from families with a high risk of parental AUDs.

Is Binge Drinking Onset Timing Related to Academic Performance, Engagement, and Aspirations Among Youth in the COMPASS Study?

BACKGROUND

Some evidence suggests early initiation of alcohol use is associated with academic underachievement; however, substance use onset is an ambiguous concept, resulting in mixed findings across studies. Moreover, the quantity of early use is likely an important determinant. Binge drinking is a common pattern among younger cohorts, and is shown to magnify the risk of related problems.

OBJECTIVES

The current study explored how students who initiated binge drinking early (grade 10 or earlier) or later in high school (grade 11 or 12) differed in relation to a variety of academic indices.

METHODS

The sample consisted of 19,764 grade 9 to 12 students with at least 2 years of linked-longitudinal data from Year 1(Y₁: 2012-2013), Year 2(Y₂: 2013-2014), and Year 3(Y₃: 2014-2015) of the COMPASS study. Separate multinomial GEE models tested the likelihood of different responses to outcome measures of academic goals, engagement, preparedness, and performance based on the timing of binge drinking onset. Models adjusted for binge drinking initiation in varying frequencies, gender, grade, race/ethnicity, and smoking.

RESULTS

Compared to students with earlier onsets of binge drinking, youth with later onsets were more likely to regularly attend class, complete their homework, value good grades, achieve high English or Math marks, have graduate/professional degree ambitions, and expect to obtain a college/trade school diploma after high school, yet they were less likely to expect to achieve a bachelor's degree.

CONCLUSION

Results highlight the importance of substance use prevention programs targeting early adolescents. Both delaying and preventing binge drinking have the potential to improve scholastic outcomes.

Education, substance use, and HIV risk among orphaned adolescents in Eastern Zimbabwe

There is a growing interest in education as a means to reduce HIV infection in vulnerable children in sub-Saharan Africa; however, the mechanisms by which education reduces HIV infection remain uncertain. Substance use has been associated with high-risk sexual behaviour and could lie on the causal pathway between education and HIV risk. Therefore, we used multivariable regression to measure associations between: (i) orphanhood and substance use (alcohol, recreational drugs, and smoking), (ii) substance use and sexual risk behaviours, and (iii) school enrolment and substance use, in adolescents aged 15-19 years, in Eastern Zimbabwe. We found substance use to be low overall (6.4%, 3.2%, and 0.9% of males reported alcohol, drug, and cigarette use; <1% of females reported any substance use), but was more common in male maternal and double orphans than non-orphans. Substance use was positively associated with early sexual debut, number of sexual partners, and engaging in transactional sex, while school enrolment was associated with lower substance use in males. We conclude that education may reduce sexual risk behaviours and HIV infection rates among male adolescents in sub-Saharan Africa, in part, by reducing substance abuse.

Inequities in coverage of smokefree space policies within the United States

BACKGROUND

Previous studies have found extensive geographic and demographic differences in tobacco use. These differences have been found to be reduced by effective public policies, including banning smoking in public spaces. Smokefree indoor and outdoor spaces reduce secondhand smoke exposure and denormalize smoking.

METHODS

We evaluated regional and demographic differences in the proportion of the population covered by smokefree policies enacted in the United States prior to 2014, for both adults and children.

RESULTS

Significant differences in coverage were found by ethnicity, region, income, and education (p < 0.001). Smokefree policy coverage was lower for jurisdictions with higher proportions of poor households, households with no high school diploma and the Southeast region. Increased ethnic heterogeneity was found to be a significant predictor of coverage in indoor "public spaces generally", meaning that diversity is protective, with differential effect by region (p = 0.004) - which may relate to urbanicity. Children had a low level of protection in playgrounds and schools (~10% covered nationwide) - these spaces were found to be covered at lower rates than indoor spaces.

CONCLUSIONS

Disparities in smokefree space policies have potential to exacerbate existing health inequities. A national increase in smokefree policies to protect children in playgrounds and schools is a crucial intervention to reduce such inequities.

The Influence of Paternal Separation, Paternal History of Alcohol Use Disorder Risk, and Early Substance Use on Offspring Educational Attainment by Young Adulthood

OBJECTIVE

This study aimed to determine the associations among paternal alcohol problems, separation, and educational attainment in European American and African American offspring and whether offspring early alcohol/tobacco/marijuana use influenced these associations.

METHOD

Families with offspring ages 13-19 years at intake were selected from state birth records and screened by telephone to determine high-risk or low-risk status (with/without paternal heavy drinking). Families of men with two or more driving-under-the-influence offenses were added as a very-high-risk group. Data from 340 African American and 288 European American offspring who were not enrolled in school at their last interview were analyzed. Educational attainment was modeled as less than high school, high school only (reference category), and some college or higher. Separation was defined as offspring report of not having lived continuously in the same household with their biological father from birth to age 14. Analyses were stratified by race.

RESULTS

In European Americans, neither family risk status nor early alcohol/tobacco/marijuana use was associated with educational outcomes. However, paternal separation significantly elevated the likelihood of not completing high school in all models (relative risk ratios [RRRs] = 6.0-8.1, p <.001). For African American offspring, likelihoods of high school noncompletion were elevated marginally for paternal separation in only one model, but significantly for early marijuana use (RRRs = 2.8-3.2, p < .05). Very-high-risk status significantly reduced the likelihood of post-high school education in an adjusted model (RRR = 0.4, p < .05).

CONCLUSIONS

High school noncompletion was significantly associated with paternal separation in European Americans and with early marijuana use in African American offspring. In addition, very-high-risk status reduced the likelihood of post-high school education in African American offspring only, suggesting that research with ethnically diverse samples yields important differences when examining outcomes of both separation and substance use on offspring education.

Gender and race/ethnic differences in the persistence of alcohol, drug, and poly-substance use disorders

AIMS

To examine gender and racial/ethnic differences in the effect of substance use disorder (SUD) type on SUD persistence.

METHODS

Data were provided by 1025 women and 1835 men from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) to examine whether gender and race/ethnicity (Non-Hispanic White, Black, Hispanic) moderate the effects of DSM-IV defined past-12 month SUD type (alcohol, drug, poly-substance) on SUD persistence at 3-year follow-up, controlling for covariates. Using gender-stratified weighted binary logistic regression, we examined predictors of SUD persistence, tested an SUD type by race/ethnicity interaction term, and calculated and conducted Bonferroni corrected pairwise comparisons of predicted probabilities.

RESULTS

SUD persistence rates at 3-year follow-up differed for SUD type by gender by race/ethnicity sub-group, and ranged from 31% to 81%. SUD persistence rates were consistently higher among poly-substance users; patterns were mixed in relation to gender and race/ethnicity. Among women, alcohol disordered Hispanics were less likely to persist than Whites. Among men, drug disordered Hispanics were less likely to persist than Whites. Also, Black men with an alcohol or drug use disorder were less likely to persist than Whites, but Black men with a poly-substance use disorder were more likely to persist than Hispanics.

CONCLUSIONS

The effect of SUD type on SUD persistence varies by race/ethnicity, and the nature of these relationships is different by gender. Such knowledge could inform tailoring of SUD screening and treatment programs, potentially increasing their impact.

EDUCATIONAL ATTAINMENT AS A PROTECTIVE FACTOR FOR PSYCHIATRIC DISORDERS: FINDINGS FROM A NATIONALLY REPRESENTATIVE LONGITUDINAL STUDY

OBJECTIVE

This study examined cross-sectional and longitudinal relationships between educational attainment and psychiatric disorders (i.e., mood, anxiety, substance use, and personality disorders) using a nationally representative survey of US adults.

METHOD

We used data from Waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (N = 34,653). Bivariate and multiple logistic regressions examined cross-sectional and longitudinal associations between educational attainment and a variety of past-year and incident anxiety, mood, and substance use disorders, controlling for sociodemographics and psychiatric disorder comorbidity.

RESULTS

Adjusted cross-sectional data indicated that educational attainment below a graduate or professional degree at Wave 2 was associated with significantly higher odds of substance use and/or dependence disorders (adjusted odds ratio range (AORR = 1.55-2.55, P < 0.001). Longitudinal adjusted regression analyses indicated that individuals reporting less than a college education at Wave 1 were at significantly higher odds of experiencing any incident mood (AORR 1.49-1.64, P < 0.01), anxiety (AORR 1.35-1.69, P < 0.01), and substance use disorder (AORR 1.50-2.02, P < 0.01) at Wave 2 even after controlling for other sociodemographic variables and psychiatric comorbidity.

CONCLUSION

Findings lend support to other published research demonstrating that educational attainment is protective against developing a spectrum of psychiatric disorders. Mechanisms underlying this relationship are speculative and in need of additional research.

The impact of adolescent exposure to medical marijuana laws on high school completion, college enrollment and college degree completion

BACKGROUND

There is concern that medical marijuana laws (MMLs) could negatively affect adolescents. To better understand these policies, we assess how adolescent exposure to MMLs is related to educational attainment.

METHODS

Data from the 2000 Census and 2001-2014 American Community Surveys were restricted to individuals who were of high school age (14-18) between 1990 and 2012 (n=5,483,715). MML exposure was coded as: (i) a dichotomous "any MML" indicator, and (ii) number of years of high school age exposure. We used logistic regression to model whether MMLs affected: (a) completing high school by age 19; (b) beginning college, irrespective of completion; and (c) obtaining any degree after beginning college. A similar dataset based on the Youth Risk Behavior Survey (YRBS) was also constructed for confirmatory analyses assessing marijuana use.

RESULTS

MMLs were associated with a 0.40 percentage point increase in the probability of not earning a high school diploma or GED after completing the 12th grade (from 3.99% to 4.39%). High school MML exposure was also associated with a 1.84 and 0.85 percentage point increase in the probability of college non-enrollment and degree non-completion, respectively (from 31.12% to 32.96% and 45.30% to 46.15%, respectively). Years of MML exposure exhibited a consistent dose response relationship for all outcomes. MMLs were also associated with 0.85 percentage point increase in daily marijuana use among 12th graders (up from 1.26%).

CONCLUSIONS

Medical marijuana law exposure between age 14 to 18 likely has a delayed effect on use and education that persists over time.

Top-Down Network Effective Connectivity in Abstinent Substance Dependent Individuals

Objective

We hypothesized that compared to healthy controls, long-term abstinent substance dependent individuals (SDI) will differ in their effective connectivity between large-scale brain networks and demonstrate increased directional information from executive control to interoception-, reward-, and habit-related networks. In addition, using graph theory to compare network efficiencies we predicted decreased small-worldness in SDI compared to controls.

Methods

50 SDI and 50 controls of similar sex and age completed psychological surveys and resting state fMRI. fMRI results were analyzed using group independent component analysis; 14 networks-of-interest (NOI) were selected using template matching to a canonical set of resting state networks. The number, direction, and strength of connections between NOI were analyzed with Granger Causality. Within-group thresholds were p<0.005 using a bootstrap permutation. Between group thresholds were p<0.05, FDR-corrected for multiple comparisons. NOI were correlated with behavioral measures, and group-level graph theory measures were compared.

Results

Compared to controls, SDI showed significantly greater Granger causal connectivity from right executive control network (RECN) to dorsal default mode network (dDMN) and from dDMN to basal ganglia network (BGN). RECN was negatively correlated with impulsivity, behavioral approach, and negative affect; dDMN was positively correlated with impulsivity. Among the 14 NOI, SDI showed greater bidirectional connectivity; controls showed more unidirectional connectivity. SDI demonstrated greater global efficiency and lower local efficiency.

Conclusions

Increased effective connectivity in long-term abstinent drug users may reflect improved cognitive control over habit and reward processes. Higher global and lower local efficiency across all networks in SDI compared to controls may reflect connectivity changes associated with drug dependence or remission and requires future, longitudinal studies to confirm.

Did the 18 Drinking Age Promote High School Dropout? Implications for Current Policy

OBJECTIVE

Disagreement exists over whether permissive minimum legal drinking age (MLDA) laws affected underage adolescents (e.g., those age 17 years with the MLDA of 18). We used MLDA changes during the 1970s and 1980s as a natural experiment to investigate how underage exposure to permissive MLDA affected high school dropout.

METHOD

MLDA exposure was added to two data sets: (a) the 5% public use microdata samples of the 1990 and 2000 censuses (n = 3,671,075), and (b) a combined data set based on the 1991-1992 National Longitudinal Alcohol Epidemiological Survey (NLAES) and the 2001-2002 National Epidemiological Survey on Alcohol and Related Conditions (NESARC; n = 16,331). We used logistic regression to model different thresholds of MLDA on high school dropout. We also estimated models conditioned on demographic variables and familial risk of developing alcohol problems.

RESULTS

Only the MLDA of 18 predicted high school dropout. Exposure was associated with 4% and 13% higher odds of high school dropout for the census and NLAES/NESARC samples, respectively. We noted greater impact on women (5%-18%), Blacks (5%-19%), and Hispanics (6%). Self-report of parental alcohol problems was associated with 40% higher odds, which equals a 4.14-point increase in dropout rate for that population.

CONCLUSIONS

The MLDA of 18 likely had a large impact on high school dropout rates, suggesting that the presence of legal-aged peers in a high school setting increased access to alcohol for younger students. Our results also suggest that policy can promote less dangerous drinking behavior even when familial risk of alcohol use disorders is high.

All in the Family? A Twin-Based Analysis of Associations Between Occupational Risk Factors, Drinking, and Tobacco Use in Employed Men

BACKGROUND

Employment-related substance use can negatively affect both workplace and worker. Relationships between workplace characteristics and substance use may be explained by genetic and environmental effects; this research uses a co-twin control (discordant twin) design to disentangle these influences.

METHODS

This study compared population-level to discordant twin pair relationships to analyze the genetic and environmental influences of work-related risks on substance use in N = 2,138 dizygotic and monozygotic male twins from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders. Negative binomial and logistic regressions were fit to predict differences in the frequency of drinking, typical and maximum number of drinks, the number of cigarettes per day, and any binge drinking or any tobacco use across occupation, work hours, job strain, problems with coworkers, and perceived job insecurity.

RESULTS

In population-level analyses, several work-related variables were associated with substance use. The population-level associations of occupation with typical and maximum drinks per day and of problems with coworkers to binge drinking were not significant at the twin level. At both the population and discordant twin levels, only higher occupational status was associated with a lower likelihood of regular tobacco use (odds ratio 0.44, 95% confidence interval 0.21, 0.94).

CONCLUSIONS

Variation in genes and shared environment appears to account for many of the population-level relationships between work-related stressors and substance use. Work stressors may not be the most fruitful intervention point when aiming to reduce alcohol or tobacco use, although men in certain high-stress occupations may be at greater risk for substance use.

Keep off the grass? Cannabis, cognition and addiction

In an increasing number of states and countries, cannabis now stands poised to join alcohol and tobacco as a legal drug. Quantifying the relative adverse and beneficial effects of cannabis and its constituent cannabinoids should therefore be prioritized. Whereas newspaper headlines have focused on links between cannabis and psychosis, less attention has been paid to the much more common problem of cannabis addiction. Certain cognitive changes have also been attributed to cannabis use, although their causality and longevity are fiercely debated. Identifying why some individuals are more vulnerable than others to the adverse effects of cannabis is now of paramount importance to public health. Here, we review the current state of knowledge about such vulnerability factors, the variations in types of cannabis, and the relationship between these and cognition and addiction.

Why young people's substance use matters for global health

During puberty, when young people are completing their education, transitioning into employment, and forming longer-term intimate relationships, a shift in emotional regulation and an increase in risky behaviour, including substance use, is seen. This Series paper considers the potential effects of alcohol, tobacco, and illicit drug use during this period on: social, psychological, and health outcomes in adolescence and young adulthood; role transitions, and later health and social outcomes of regular substance use initiated in adolescence; and the offspring of young people who use substances. We sourced consistent support for causal relations between substance use and outcomes and evidence of biological plausibility from different but complementary research designs. Many adverse health and social outcomes have been associated with different types of substance use. The major challenge lies in deciding which are causal. Furthermore, qualitatively different harms are associated with different substances, differences in life stage when these harms occur, and the quality of evidence for different substances and health outcomes varies substantially. The preponderance of evidence comes from a few high-income countries, thus whether the same social and health outcomes would occur in other countries and cultures is unclear. Nonetheless, the number of harms that are causally related to substance use in young people warrant high-quality research design interventions to prevent or ameliorate these harms.

Are IQ and educational outcomes in teenagers related to their cannabis use? A prospective cohort study

There is much debate about the impact of adolescent cannabis use on intellectual and educational outcomes. We investigated associations between adolescent cannabis use and IQ and educational attainment in a sample of 2235 teenagers from the Avon Longitudinal Study of Parents and Children. By the age of 15, 24% reported having tried cannabis at least once. A series of nested linear regressions was employed, adjusted hierarchically by pre-exposure ability and potential confounds (e.g. cigarette and alcohol use, childhood mental-health symptoms and behavioural problems), to test the relationships between cumulative cannabis use and IQ at the age of 15 and educational performance at the age of 16. After full adjustment, those who had used cannabis ⩾ 50 times did not differ from never-users on either IQ or educational performance. Adjusting for group differences in cigarette smoking dramatically attenuated the associations between cannabis use and both outcomes, and further analyses demonstrated robust associations between cigarette use and educational outcomes, even with cannabis users excluded. These findings suggest that adolescent cannabis use is not associated with IQ or educational performance once adjustment is made for potential confounds, in particular adolescent cigarette use. Modest cannabis use in teenagers may have less cognitive impact than epidemiological surveys of older cohorts have previously suggested.

Effect of Adolescent Cigarette Smoking on Adulthood Substance Use and Abuse: The Mediating Role of Educational Attainment

BACKGROUND

Even though the association between cigarette smoking and later substance use has been shown, there is still no compelling evidence that demonstrates the long-term effects in a high drug using community in African Americans. Few studies have examined the mediating mechanisms of the effect of adolescent cigarette smoking on the drug progression pathway.

OBJECTIVES

We examined the long-term influence of adolescent smoking on later illegal drug use in a cohort of urban African Americans, and the mediating role of educational attainment in the drug progression pathway.

METHODS

The study used a longitudinal dataset from the Woodlawn Project that followed 1,242 African Americans from 1966-1967 (at age 6-7) through 2002-2003 (at age 42-43). We used the propensity score matching method to find a regular and a nonregular adolescent smoking group that had similar childhood characteristics; we used the matched sample to assess the association between adolescent smoking and drug progression, and the mediating role of educational attainment.

RESULTS

Adolescent regular smokers showed significantly higher odds of using marijuana, cocaine, and heroin, having alcohol abuse problems and any drug dependence, and abuse problems in adulthood. We found that educational attainment mediated most of the drug progression pathway, including cigarette smoking, marijuana, cocaine and heroin use, and drug dependence or abuse problems in adulthood, but not alcohol abuse.

CONCLUSIONS

More focus needs to be put on high school dropout and development of interventions in community settings for African Americans to alter the pathway for drug progression for adolescents who use cigarettes regularly.

Socioeconomic variations in nicotine dependence in rural southwest China

Background

This study examines how nicotine dependence is distributed across socioeconomic gradients in rural Yunnan province, which has the most ethnic minorities in one province in southwest China.

Methods

A cross-sectional survey was conducted in four rural areas of Yunnan province among 17,158 consenting individuals aged ≥18 years in 2011. Information on demographic characteristics and smoking habits was obtained using a standard questionnaire. The Fagerstrom Test for Nicotine Dependence (FTND) was applied to assess nicotine dependence. Multilevel logistic regression was used to model the variation in prevalence of nicotine dependence.

Results

In the study population, the overall prevalence of current smokers and nicotine dependence was 32.4 % and 31.6 %, respectively. Females were much less likely to have nicotine addiction than males: odds ratio (OR) of 0.01 (95 % CI: 0.008 – 0.012). Higher annual household income was associated with a greater risk of nicotine dependence (OR 1.09, 95 % CI: 1.01 – 1.17). Adults who grew tobacco were more likely to have nicotine addiction (OR 1.22, 95 % CI 1.07 – 1.41). Individual educational level was inversely associated with the probability of nicotine dependence (OR 0.63, 95 % CI 0.55 – 0.72), lower community educational level was also associated with an increased risk of nicotine dependence (OR 0.94, 95 % CI 0.92 – 0.98).

Conclusions

Nicotine dependence showed significant variations across different indicators of both contextual and individual socioeconomic status in rural southwest China. Future interventions on tobacco cessation should give increased attention to men, tobacco farmers, less educated or poorer persons, and lower educational level communities.

Early onset alcohol use and self-harm: a discordant twin analysis

BACKGROUND

Self-harm has considerable societal and economic costs and has been extensively studied in relation to alcohol involvement. Although early onset alcohol use (EAU) has been causally linked to maladaptive clinical outcomes, its association with self-harm is less well characterized. This study aimed to further examine the link between EAU and both nonsuicidal self-injury (NSSI) and suicide attempt (SA), and elucidate shared familial and causal/individual-specific pathways that explain this co-occurrence.

METHODS

Using data from 6,082 Australian same-sex twin pairs (1,732 monozygotic [MZ] and 1,309 dizygotic [DZ]), ages 23 to 40, we examined prevalence rates of NSSI and SA among twin pairs concordant and discordant for EAU. Conditional logistic regression, controlling for early clinical covariates and the influence of zygosity on EAU, was used to examine the odds ratio (OR) of self-harm within twin pairs discordant for EAU.

RESULTS

Prevalence rates of both NSSI and SA were highest among twin pairs concordant for EAU and for twins who reported EAU within discordant twin pairs. Results from discordant twin analyses revealed nearly 4-fold increased odds of SA for the twin who endorsed EAU, and this OR was equal across MZ and DZ twins. EAU also was associated with elevated odds of NSSI (OR = 7.62), although this was only the case for DZ twins in discordant pairs.

CONCLUSIONS

The equivalent increase in odds of SA for both MZ and DZ twins suggests that causal or individual-specific influences explain the link between EAU and SA. For NSSI, elevated odds for DZ twins and nonsignificant findings for MZ twins implicate correlated genetic factors in the association between EAU and NSSI. Future studies should test mechanisms through which EAU may causally influence SA, as well as examine whether genetic risk for third variables (e.g., negative urgency, stress reactivity) may explain the genetic overlap between EAU and NSSI.

Bulimic Behaviors and Early Substance Use: Findings from a Cotwin-Control Study

BACKGROUND

Bulimic behaviors (i.e., binge eating and compensatory behaviors) and substance use frequently co-occur. However, the etiology underlying this association is poorly understood. This study evaluated the association between bulimic behaviors and early substance use, controlling for genetic and shared environmental factors.

METHODS

Participants were 3,540 young adult women from the Missouri Adolescent Female Twin Study. A telephone adaptation of the Semi-Structured Assessment for the Genetics of Alcoholism interview assessed DSM-IV bulimic behaviors, substance use, and other psychological characteristics. Lifetime bulimic behaviors were examined in twin pairs concordant and discordant for early substance use. Logistic regressions were adjusted for the nonindependence of twin data, zygosity, age, body mass index, early menarche (onset before age 12), and early sex (first consensual sexual intercourse before age 15).

RESULTS

In the entire study population, women who reported early use of alcohol or nicotine were more likely to engage in bulimic behaviors after adjusting for covariates. In 53 pairs of monozygotic twins discordant for alcohol experimentation before age 15, the twin who reported early alcohol experimentation had 3.21 (95% confidence interval = 1.54 to 6.67) times higher odds of reporting bulimic behaviors than the cotwin who did not report early alcohol experimentation, even after adjustment for covariates.

CONCLUSIONS

Findings suggest that early alcohol experimentation may contribute to the development of bulimic behaviors via mechanisms extending beyond shared vulnerability, including individual-specific environmental experiences or causal pathways.

Genetic and Environmental Interplay in Adolescent Substance Use Disorders

Adolescent substance use is of considerable public health importance. This narrative review provides a brief background to genetically informative research methodologies and highlights key recent literature examining the interplay between genetic and environmental influences in the etiology of substance use. Twin studies have quantified the magnitude of genetic and environmental influences, and more recently co-relative and Children of Twin designs have shown environments can moderate heritability. Studies have identified a number of specific gene variants (e.g. OPRM1, DRD4, 5HTTLPR) that interact with parenting and peer influence, and the effectiveness of interventions may vary by genotype. However, little research has taken into account the stage-sequential nature of substance use. This may obscure important differences in the genetic and environmental influences, and their interplay, at the stages of escalation to problem use. Future research needs to build on existing methodologies to disentangle the complexities of progression in adolescent substance use.

Life Course Trajectories of Labour Market Participation among Young Adults Who Experienced Severe Alcohol-Related Health Outcomes: A Retrospective Cohort Study

Background

Long-term employment trajectories of young problem drinkers are poorly understood.

Methods

We constructed retrospective labour market participation histories at ages 18–34 of 64 342 persons born in 1969–1982. Beginning from the year of each subject’s 18^th birthday, we extracted information from the records of Statistics Finland on educational attainment, main type of economic activity, months in employment, and months in unemployment for a minimum of seven years (range 7–16 years). We used information on the timing of alcohol-related hospitalizations and deaths in the same period to define problem drinkers with early onset limited course, early onset persistent course, and late onset problem drinking.

Results

Early onset limited course problem drinkers improved their employment considerably by age, whereas early onset persistent problem drinkers experienced a constant decline in their employment by age. From the age of 18 to 34, early onset persistent problem drinkers were in employment merely 12% of the time, in comparison with 39% among the early onset limited course problem drinkers, and 58% among the general population.

Conclusions

These results indicate that young adults who were retrospectively defined as having early onset persistent course problem drinking were extensively marginalized from the labour market early on during their life course, and that their employment trajectory was significantly worse compared to other problem drinkers.

Adolescent cannabis and tobacco use and educational outcomes at age 16: birth cohort study

AIMS

To investigate the relationship between cannabis and tobacco use by age 15 and subsequent educational outcomes.

DESIGN

Birth cohort study.

SETTING

England.

PARTICIPANTS

The sample was drawn from the Avon Longitudinal Study of Parents and Children; a core sample of 1155 individuals had complete information on all the variables.

MEASUREMENTS

The main exposures were cannabis and tobacco use at age 15 assessed in clinic by computer-assisted questionnaire and serum cotinine. The main outcomes were performance in standardized assessments at 16 [Key Stage 4, General Certificate of Secondary Education (GCSE)] in English and mathematics (mean scores), completion of five or more assessments at grade C level or higher and leaving school having achieved no qualifications. Analyses were sequentially adjusted for multiple covariates using a hierarchical approach. Covariates considered were: maternal substance use (ever tobacco or cannabis use, alcohol use above recommended limits); life course socio-economic position (family occupational class, maternal education, family income); child sex; month and year of birth; child educational attainment prior to age 11 (Key Stage 2); child substance use (tobacco, alcohol and cannabis) prior to age 15 and child conduct disorder.

FINDINGS

In fully adjusted models both cannabis and tobacco use at age 15 were associated with subsequent adverse educational outcomes. In general, the dose-response effect seen was consistent across all educational outcomes assessed. Weekly cannabis use was associated negatively with English GCSE results [grade point difference (GPD), -5.93, 95% confidence interval (CI) = -8.34, -3.53] and with mathematics GCSE results (GPD, -6.91, 95% CI = -9.92, -3.89). Daily tobacco smoking was associated negatively with English GCSE (GPD, -11.90, 95% CI = -13.47, -10.33) and with mathematics GCSE (GPD, -16.72, 95% CI = -18.57, -14.86). The greatest attenuation of these effects was seen on adjustment for other substance use and conduct disorder. Following adjustment, tobacco appeared to have a consistently stronger effect than cannabis.

CONCLUSIONS

Both cannabis and tobacco use in adolescence are associated strongly with subsequent adverse educational outcomes. Given the non-specific patterns of association seen and the attenuation of estimates on adjustment, it is possible that these effects arise through non-causal mechanisms, although a causal explanation cannot be discounted. © 2015 Society for the Study of Addiction.

School performance and alcohol-related disorders in early adulthood: a Swedish national cohort study

Background Alcohol misuse is an important global health determinant and a major contributor to health inequalities. We aimed to investigate the association between school performance and alcohol-related disorders in early adulthood in a longitudinal register-based national cohort study.

Methods We followed a register-based national cohort of Swedish citizens born 1973–1984 (N = 948 440) from compulsory school graduation at age 15–16 to 2009. We divided the population into five groups: high school marks (> mean + 1 SD); high average (between mean and mean + 1 SD); low average (between mean and mean − 1 SD); low (< mean – 1SD); and missing. Cox proportional hazard models were used to investigate the relation between school marks at time of graduation and hospital care for alcohol-related disorders in early adulthood.

Results There was a steep gradient in the risk of alcohol-related disorders related to school performance. In comparison with peers in the top category of school marks, students with low marks had adjusted hazard ratios of 8.02 [95% confidence interval (CI) 7.20 to 8.91], low average 3.02 (2.72 to 3.35) and high average 1.55 (1.39 to 1.73). The risk associated with low school marks was stronger in the male population and in the group from high socioeconomic background.

Conclusions The study demonstrated a strong graded relation between low school performance and alcohol-related disorders in young adulthood. School performance should be taken into account when developing prevention programmes/policies targeting alcohol misuse among teenagers and young adults, especially if the aim is to reach high-risk groups.

What has research over the past two decades revealed about the adverse health effects of recreational cannabis use?

AIMS

To examine changes in the evidence on the adverse health effects of cannabis since 1993.

METHODS

A comparison of the evidence in 1993 with the evidence and interpretation of the same health outcomes in 2013.

RESULTS

Research in the past 20 years has shown that driving while cannabis-impaired approximately doubles car crash risk and that around one in 10 regular cannabis users develop dependence. Regular cannabis use in adolescence approximately doubles the risks of early school-leaving and of cognitive impairment and psychoses in adulthood. Regular cannabis use in adolescence is also associated strongly with the use of other illicit drugs. These associations persist after controlling for plausible confounding variables in longitudinal studies. This suggests that cannabis use is a contributory cause of these outcomes but some researchers still argue that these relationships are explained by shared causes or risk factors. Cannabis smoking probably increases cardiovascular disease risk in middle-aged adults but its effects on respiratory function and respiratory cancer remain unclear, because most cannabis smokers have smoked or still smoke tobacco.

CONCLUSIONS

The epidemiological literature in the past 20 years shows that cannabis use increases the risk of accidents and can produce dependence, and that there are consistent associations between regular cannabis use and poor psychosocial outcomes and mental health in adulthood.