Association between adolescent alcohol use and cognitive function in young adulthood: A co-twin comparison study.

BACKGROUND AND AIMS: Studies on adolescent alcohol use and cognition are often unable to separate the potential causal effects of alcohol use on cognition from shared etiological influences, including genetic influences or other substance use comorbidities also known to be associated with cognition, such as nicotine use. The present study aimed to fill this gap and clarify the relationship between adolescent alcohol use and young adult cognition by accounting for both measured and unmeasured confounders. DESIGN: A random effects model accounting for nesting in families was used to control for measured confounders. Next, co-twin comparisons were conducted within the full sample and in monozygotic twin pairs (MZ) to control for unmeasured genetic and environmental confounders shared by co-twins. PARTICIPANTS/SETTING: Participants were 812 individuals (58.6% female, 361 complete pairs, 146 MZ pairs) from the longitudinal FinnTwin12 study in Finland. MEASUREMENTS: Adolescent alcohol use was indexed with measures of frequency of use and intoxication averaged across ages 14 and 17. Cognitive outcomes were measured at average age 22 and included Trail Making Test, California Stroop test, Wechsler Adult Intelligence subtests (Vocabulary, Block Design, Digit Symbol), Digit Span subtest of Wechsler Memory Scale, Mental Rotation Test and Object Location Memory test. Covariates included sex, parental education, general cognitive ability, current alcohol use and nicotine use. FINDINGS: Greater frequency of alcohol use and frequency of intoxication across adolescence was associated with decreased vocabulary scores in the co-twin control [freq: stnd beta = -0.12, 95% confidence interval (CI) = -0.234, -0.013] and MZ only co-twin control models (freq: stnd beta = -0.305, 95% CI = -0.523, -0.087; intox: stnd beta = -0.301, 95% CI = -0.528, -0.074). CONCLUSIONS: In Finland, there appears to be little evidence that adolescent alcohol use causes cognitive deficits in young adulthood, except modest evidence for association of higher adolescent alcohol use with lower young adult vocabulary scores.

Medications for alcohol-use disorder and follow-up after hospitalization for alcohol withdrawal: A multicenter study.

BACKGROUND: Alcohol withdrawal is a common reason for admission to acute care hospitals. Prescription of medications for alcohol-use disorder (AUD) and close outpatient follow-up are commonly recommended, but few studies report their effects on postdischarge outcomes. OBJECTIVES: The objective of this study is to evaluate the effects of medications for AUD and follow-up appointments on readmission and abstinence. METHODS: This retrospective cohort study evaluated veterans admitted for alcohol withdrawal to medical services at 19 Veteran Health Administration hospitals between October 1, 2018 and September 30, 2019. Factors associated with all-cause 30-day readmission and 6-month abstinence were examined using logistic regression. RESULTS: Of the 594 patients included in this study, 296 (50.7%) were prescribed medications for AUD at discharge and 459 (78.5%) were discharged with follow-up appointments, including 251 (42.8%) with a substance-use clinic appointment, 191 (32.9%) with a substance-use program appointment, and 73 (12.5%) discharged to a residential program. All-cause 30-day readmission occurred for 150 patients (25.5%) and 103 (17.8%) remained abstinent at 6 months. Medications for AUD and outpatient discharge appointments were not associated with readmission or abstinence. Discharge to residential treatment program was associated with reduced 30-day readmission (adjusted odds ratio [AOR]: 0.39, 95% confidence interval [95% CI]: 0.18-0.82) and improved abstinence (AOR: 2.50, 95% CI: 1.33-4.73). CONCLUSIONS: Readmission and return to heavy drinking are common for patients discharged for alcohol withdrawal. Medications for AUD were not associated with improved outcomes. The only intervention at the time of discharge that improved outcomes was discharge to residential treatment program, which was associated with decreased readmission and improved abstinence.

Patterns and predictors of alcohol misuse trajectories from adolescence through early midlife.

We took a multilevel developmental contextual approach and characterized trajectories of alcohol misuse from adolescence through early midlife, examined genetic and environmental contributions to individual differences in those trajectories, and identified adolescent and young adult factors associated with change in alcohol misuse. Data were from two longitudinal population-based studies. FinnTwin16 is a study of Finnish twins assessed at 16, 17, 18, 25, and 35 years (N = 5659; 52% female; 32% monozygotic). The National Longitudinal Study of Adolescent to Adult Health (Add Health) is a study of adolescents from the United States, who were assessed at five time points from 1994 to 2018 (N = 18026; 50% female; 64% White, 21% Black, 4% Native American, 7% Asian, 9% Other race/ethnicity). Alcohol misuse was measured as frequency of intoxication in FinnTwin16 and frequency of binge drinking in Add Health. In both samples, trajectories of alcohol misuse were best described by a quadratic growth curve: Alcohol misuse increased across adolescence, peaked in young adulthood, and declined into early midlife. Individual differences in these trajectories were primarily explained by environmental factors. Several adolescent and young adult correlates were related to the course of alcohol misuse, including other substance use, physical and mental health, and parenthood.

Contemporary Management and Outcomes of Veterans Hospitalized With Alcohol Withdrawal: A Multicenter Retrospective Cohort Study.

OBJECTIVES: Few studies describe contemporary alcohol withdrawal management in hospitalized settings or review current practices considering the guidelines by the American Society of Addiction Medicine (ASAM). METHODS: We conducted a retrospective cohort study of patients hospitalized with alcohol withdrawal on medical or surgical wards in 19 Veteran Health Administration (VHA) hospitals between October 1, 2018, and September 30, 2019. Demographic and comorbidity data were obtained from the Veteran Health Administration Corporate Data Warehouse. Inpatient management and hospital outcomes were obtained by chart review. Factors associated with treatment duration and complicated withdrawal were examined. RESULTS: Of the 594 patients included in this study, 51% were managed with symptom-triggered therapy alone, 26% with fixed dose plus symptom-triggered therapy, 10% with front loading regimens plus symptom-triggered therapy, and 3% with fixed dose alone. The most common medication given was lorazepam (87%) followed by chlordiazepoxide (33%), diazepam (14%), and phenobarbital (6%). Symptom-triggered therapy alone (relative risk [RR], 0.68; 95% confidence interval [CI], 0.57-0.80) and front loading with symptom-triggered therapy (RR, 0.75; 95% CI, 0.62-0.92) were associated with reduced treatment duration. Lorazepam (RR, 1.20; 95% CI, 1.02-1.41) and phenobarbital (RR, 1.28; 95% CI, 1.06-1.54) were associated with increased treatment duration. Lorazepam (adjusted odds ratio, 4.30; 95% CI, 1.05-17.63) and phenobarbital (adjusted odds ratio, 6.51; 95% CI, 2.08-20.40) were also associated with complicated withdrawal. CONCLUSIONS: Overall, our results support guidelines by the ASAM to manage patients with long-acting benzodiazepines using symptom-triggered therapy. Health care systems that are using shorter acting benzodiazepines and fixed-dose regimens should consider updating alcohol withdrawal management pathways to follow ASAM recommendations.

Proteomic insights into mental health status: plasma markers in young adults.

Global emphasis on enhancing prevention and treatment strategies necessitates an increased understanding of the biological mechanisms of psychopathology. Plasma proteomics is a powerful tool that has been applied in the context of specific mental disorders for biomarker identification. The p-factor, also known as the "general psychopathology factor", is a concept in psychopathology suggesting that there is a common underlying factor that contributes to the development of various forms of mental disorders. It has been proposed that the p-factor can be used to understand the overall mental health status of an individual. Here, we aimed to discover plasma proteins associated with the p-factor in 775 young adults in the FinnTwin12 cohort. Using liquid chromatography-tandem mass spectrometry, 13 proteins with a significant connection with the p-factor were identified, 8 of which were linked to epidermal growth factor receptor (EGFR) signaling. This exploratory study provides new insight into biological alterations associated with mental health status in young adults.

Comparison of internal medicine applicant and resident characteristics with performance on ACGME milestones.

Internal medicine (IM) residency programs select applicants based on several metrics. Factors predicting success during residency are unclear across studies. To identify whether specific applicant or resident factors are associated with IM resident performance using ACGME milestones. We tested for associations between applicant factors available prior to the start of IM residency and resident factors measured during IM residency training, and resident performance on ACGME milestones across three consecutive years of IM training between 2015-2020. Univariable and multivariable linear regression modeling was used to test associations. Eighty-nine categorical IM residents that completed 3 consecutive years of training were included. Median age was 28 years (IQR 27-29) and 59.6% were male. Mean ACGME milestone scores increased with each post-graduate year (PGY) from 3.36 (SD 0.19) for PGY-1, to 3.80 (SD 0.15) for PGY-2, to 4.14 (SD 0.15) for PGY-3. Univariable modeling suggested referral to the clinical competency committee (CCC) for professionalism concerns was negatively associated with resident performance during each PGY. No applicant or resident factors included in the final multivariable regression models (age at starting residency, USMLE Step scores, interview score, rank list position, ITE scores) were associated with ACGME milestone scores for PGY-1 and PGY-2. Referral to the CCC for professionalism was negatively associated with resident performance during PGY-3. Residency selection factors did not predict resident milestone evaluation scores. Referral to the CCC was associated with significantly worse resident evaluation scores, suggesting professionalism may correlate with clinical performance.

Paternal and Maternal Problem Drinking and Lifetime Problem Drinking of Their Adult Children.

Parents' alcohol use is associated with alcohol use of their adolescent offspring, but does this association extend to the adulthood of the offspring? We examined associations of paternal and maternal problem drinking with lifetime problem drinking of their adult offspring prospectively assessed in a population-based Finnish twin-family cohort (FinnTwin16). Problem drinking (Malmö-modified Michigan Alcoholism Screening Test) was self-reported separately by mothers and fathers when their children were 16. The children reported on an extended lifetime version of the same measure during their mid-twenties (21-28 years) and mid-thirties (31-37 years). 1235 sons and 1461 daughters in mid-twenties and 991 sons and 1278 daughters in mid-thirties had complete data. Correlations between fathers' and their adult children's problem drinking ranged from .12 to .18. For mothers and their adult children, these correlations ranged from .09 to .14. In multivariate models, adjustment for potential confounders had little effect on the observed associations. In this study, parental problem drinking was modestly associated with lifetime problem drinking of their adult children. This association could be detected even when the children had reached the fourth decade of life.

Clinical, environmental, and genetic risk factors for substance use disorders: characterizing combined effects across multiple cohorts.

Substance use disorders (SUDs) incur serious social and personal costs. The risk for SUDs is complex, with risk factors ranging from social conditions to individual genetic variation. We examined whether models that include a clinical/environmental risk index (CERI) and polygenic scores (PGS) are able to identify individuals at increased risk of SUD in young adulthood across four longitudinal cohorts for a combined sample of N = 15,134. Our analyses included participants of European (NEUR = 12,659) and African (NAFR = 2475) ancestries. SUD outcomes included: (1) alcohol dependence, (2) nicotine dependence; (3) drug dependence, and (4) any substance dependence. In the models containing the PGS and CERI, the CERI was associated with all three outcomes (ORs = 01.37-1.67). PGS for problematic alcohol use, externalizing, and smoking quantity were associated with alcohol dependence, drug dependence, and nicotine dependence, respectively (OR = 1.11-1.33). PGS for problematic alcohol use and externalizing were also associated with any substance dependence (ORs = 1.09-1.18). The full model explained 6-13% of the variance in SUDs. Those in the top 10% of CERI and PGS had relative risk ratios of 3.86-8.04 for each SUD relative to the bottom 90%. Overall, the combined measures of clinical, environmental, and genetic risk demonstrated modest ability to distinguish between affected and unaffected individuals in young adulthood. PGS were significant but added little in addition to the clinical/environmental risk index. Results from our analysis demonstrate there is still considerable work to be done before tools such as these are ready for clinical applications.

Exploring the relationships between adolescent alcohol misuse and later life health outcomes.

BACKGROUND: We sought to clarify the impact of adolescent alcohol misuse on adult physical health and subjective well-being. To do so, we investigated both the direct associations between adolescent alcohol misuse and early midlife physical health and life satisfaction and the indirect effects on these outcomes attributable to subsequent alcohol problems. METHOD: The sample included 2733 twin pairs (32% monozygotic; 52% female) from the FinnTwin16 study. Adolescent alcohol misuse was a composite of frequency of drunkenness, frequency of alcohol use, and alcohol problems at ages 16, 17, and 18.5. The early midlife outcomes included somatic symptoms, self-rated health, and life satisfaction at age 34. The mediators examined as part of the indirect effect analyses included alcohol problems from the Rutgers Alcohol Problem Index at ages 24 and 34. Serial mediation and co-twin comparison models were applied and included covariates from adolescence and early midlife. RESULTS: There were weak direct associations between adolescent alcohol misuse and early midlife physical health and life satisfaction. However, there was stronger evidence for indirect effects, whereby young adult and early midlife alcohol problems serially mediated the relationship between adolescent alcohol misuse and early midlife somatic symptoms (ß = 0.03, 95% CI [0.03, 0.04]), self-rated health (ß = -0.02, 95% CI [-0.03, -0.01]), and life satisfaction (ß = -0.03, CI [-0.04, -0.02]). These serial mediation effects were robust in co-twin comparison analyses. CONCLUSIONS: These results provide evidence that alcohol problems are a primary driver linking adolescent alcohol misuse and poor health outcomes across the lifespan.

Alcohol consumption at age 18-25 and number of children at a 33-year follow-up: Individual and within-pair analyses of Finnish twins.

BACKGROUND: Do drinking patterns in late adolescence/early adulthood predict lifetime childlessness and number of children? Research on this question has been only tangentially relevant and the results inconsistent. The designs used to date have been compromised by genetic and environmental confounds that are poorly controlled; covariate effects of smoking and education that are often ignored; males being understudied; population-based sampling rare, and long-term prospective studies with genetically informative designs yet to be reported. METHOD: In a 33-year follow-up, we linked the drinking patterns of >3500 Finnish twin pairs, assessed at ages 18-25, to registry data on their eventual number of children. Analyses distinguished associations of early drinking patterns with lifetime childlessness from those predictive of family size. Within-twin pair analyses used fixed-effects regression models to account for shared familial confounds and genetic liabilities. Childlessness was analyzed with Cox proportional hazards models and family size with Poisson regression. Analyses within-pairs and of twins as individuals were run before and after adjustment for smoking and education, and for oral contraceptive (OC) use in individual-level analyses of female twins. RESULTS: Baseline abstinence and heavier drinking both significantly predicted lifetime childlessness in individual-level analyses. Few abstinent women used OCs, but they were nonetheless more often eventually childless; adjusting for smoking and education did not affect this finding. Excluding childless twins, Poisson models of family size showed heavier drinking at 18-25 to be predictive of fewer children in both men and women. Those associations were replicated in within-pair analyses of dizygotic twins, each level of heavier drinking being associated with smaller families. Among monozygotic twins, associations of drinking with completed family size yielded effects of similar magnitude, reaching significance at the highest levels of consumption, ruling out familial confounds. CONCLUSIONS: Compared to moderate levels of drinking, both abstinence and heavier drinking in late adolescence/early adulthood predicted a greater likelihood of lifetime childlessness and eventual number of children. Familial confounds do not fully explain these associations.

Association of lifetime major depressive disorder with enhanced attentional sensitivity measured with P3 response in young adult twins.

Major depression is associated with alterations in the auditory P3 event-related potential (ERP). However, the persistence of these abnormalities after recovery from depressive episodes, especially in young adults, is not well known. Furthermore, the potential influence of substance use on this association is poorly understood. Young adult twin pairs (N = 177) from the longitudinal FinnTwin16 study were studied with a psychiatric interview, and P3a and P3b ERPs elicited by task-irrelevant novel sounds and targets, respectively. Dyadic linear mixed-effect models were used to distinguish the effects of lifetime major depressive disorder from familial factors and effects of alcohol problem drinking and tobacco smoking. P3a amplitude was significantly increased and P3b latency decreased, in individuals with a history of lifetime major depression, when controlling the fixed effects of alcohol abuse, tobacco, gender, twins' birth order, and zygosity. These results suggest that past lifetime major depressive disorder may be associated with enhanced attentional sensitivity.

Insulin for Hospitalized Patients With Well-Controlled Type 2 Diabetes Mellitus: A Quality Improvement Initiative.

ABSTRACT: Inpatient management of diabetes mellitus (DM) often involves substituting oral medications with insulin which can result in unnecessary insulin use. Attempting to address unnecessary insulin use, a quality improvement initiative implemented a newly developed evidence-based care pathway for inpatient diabetes management focused on patients with recent hemoglobin A1c values < 8% and no prescription of outpatient insulin. This retrospective observational preintervention and postintervention and interrupted time series analysis evaluates this intervention. Over a 21-month time period, there was a significant decrease in mean units of insulin administered per day of hospitalization from 2.7 (2.2-3.3) in the preintervention group to 1.7 (1.2-2.3) in the postintervention group ( p = .017). During the initial 72 hours after admission, a significant downward trend in mean glucose values and mean insulin units per day was seen after the intervention. There was no significant change in hypoglycemic or hyperglycemic events between the two groups. The proportion of patients who received zero units of insulin during their admission increased from 27.7% to 52.5% after the intervention ( p < .001). An evidence-based pathway for inpatient management of DM was associated with decreased insulin use without significant changes in hypoglycemic or hyperglycemic events.

A multifaceted quality improvement intervention to improve management of alcohol withdrawal on a general medicine ward: impact on benzodiazepine use.

OBJECTIVE: To measure the effects of a quality improvement intervention on length of stay and benzodiazepine use among patients admitted for alcohol use disorder. METHODS: This retrospective cohort study was performed at the Salt Lake City Veterans Affairs Medical Center. Patients 18 years and older admitted to a general medical ward with a diagnosis of alcohol related disorders who were treated for alcohol withdrawal were included. The baseline cohort included patients admitted over 12 months. The post-intervention cohort included patients admitted over 12 months. Primary outcomes were total benzodiazepine dose and length of stay. Secondary outcomes included episodes of delirium tremens and seizures. RESULTS: Total benzodiazepine dose decreased significantly over the intervention period. Length of stay also decreased. No episodes of delirium tremens or seizures were observed. CONCLUSIONS: A quality improvement intervention directed at general medicine inpatients admitted for alcohol withdrawal was associated with reductions in total benzodiazepine administration and length of stay.

The genetic background of the associations between sense of coherence and mental health, self-esteem and personality.

PURPOSE: Sense of coherence (SOC) represents coping and can be considered an essential component of mental health. SOC correlates with mental health and personality, but the background of these associations is poorly understood. We analyzed the role of genetic factors behind the associations of SOC with mental health, self-esteem and personality using genetic twin modeling and polygenic scores (PGS). METHODS: Information on SOC (13-item Orientation of Life Questionnaire), four mental health indicators, self-esteem and personality (NEO Five Factor Inventory Questionnaire) was collected from 1295 Finnish twins at 20-27 years of age. RESULTS: In men and women, SOC correlated negatively with depression, alexithymia, schizotypal personality and overall mental health problems and positively with self-esteem. For personality factors, neuroticism was associated with weaker SOC and extraversion, agreeableness and conscientiousness with stronger SOC. All these psychological traits were influenced by genetic factors with heritability estimates ranging from 19 to 66%. Genetic and environmental factors explained these associations, but the genetic correlations were generally stronger. The PGS of major depressive disorder was associated with weaker, and the PGS of general risk tolerance with stronger SOC in men, whereas in women the PGS of subjective well-being was associated with stronger SOC and the PGSs of depression and neuroticism with weaker SOC. CONCLUSION: Our results indicate that a substantial proportion of genetic variation in SOC is shared with mental health, self-esteem and personality indicators. This suggests that the correlations between these traits reflect a common neurobiological background rather than merely the influence of external stressors.

Predicting Alcohol Dependence Symptoms by Young Adulthood: A Co-Twin Comparisons Study.

Co-twin comparisons address familial confounding by controlling for genetic and environmental influences that twin siblings share. We applied the co-twin comparison design to investigate associations of adolescent factors with alcohol dependence (AD) symptoms. Participants were 1286 individuals (581 complete twin pairs; 42% monozygotic; and 54% female) from the FinnTwin12 study. Predictors included adolescent academic achievement, substance use, externalizing problems, internalizing problems, executive functioning, peer environment, physical health, relationship with parents, alcohol expectancies, life events, and pubertal development. The outcome was lifetime AD clinical criterion count, as measured in young adulthood. We examined associations of each adolescent domain with AD symptoms in individual-level and co-twin comparison analyses. In individual-level analyses, adolescents with higher levels of substance use, teacher-reported externalizing problems at age 12, externalizing problems at age 14, self- and co-twin-reported internalizing problems, peer deviance, and perceived difficulty of life events reported more symptoms of AD in young adulthood (ps < .044). Conversely, individuals with higher academic achievement, social adjustment, self-rated health, and parent-child relationship quality met fewer AD clinical criteria (ps < .024). Associations between adolescent substance use, teacher-reported externalizing problems, co-twin-reported internalizing problems, peer deviance, self-rated health, and AD symptoms were of a similar magnitude in co-twin comparisons. We replicated many well-known adolescent correlates of later alcohol problems, including academic achievement, substance use, externalizing and internalizing problems, self-rated health, and features of the peer environment and parent-child relationship. Furthermore, we demonstrate the utility of co-twin comparisons for understanding pathways to AD. Effect sizes corresponding to the associations between adolescent substance use, teacher-reported externalizing problems, co-twin-reported internalizing problems, peer deviance, and self-rated health were not significantly attenuated (p value threshold = .05) after controlling for genetic and environmental influences that twin siblings share, highlighting these factors as candidates for further research.

The Associations Between Leisure-Time Physical Activity and Academic Performance: A Twin Study.

BACKGROUND: Both genetic and environmental influences have been shown to contribute to the association between physical activity and overall academic performance. The authors examined whether leisure-time physical activity (LTPA) shares genetic and environmental variances between spelling, essay writing, reading aloud, reading comprehension, and mathematics in early adolescence. Moreover, they investigated whether genetic polymorphisms associated with physical activity behavior affect these academic skills. METHODS: Participants were 12-year-old Finnish twins (n = 4356-4370 twins/academic skill, 49% girls). Academic skills were assessed by teachers, and LTPA was self-reported. Polygenic scores for physical activity behavior were constructed from the UK Biobank. Quantitative genetic modeling and linear regression models were used to analyze the data. RESULTS: The trait correlations between LTPA and academic skills were significant but weak (r = .05-.08). The highest trait correlation was found between LTPA and mathematics. A significant genetic correlation was revealed between LTPA and essay writing (rA = .14). Regarding polygenic scores of physical activity, the highest correlations were found with reading comprehension, spelling, and essay writing, but these results only approached statistical significance (P values = .09-.15). CONCLUSIONS: The authors' results suggest that reading and writing are the academic skills that most likely share a common genetic background with LTPA.

Teacher-rated aggression and co-occurring behaviors and emotional problems among schoolchildren in four population-based European cohorts.

Aggressive behavior in school is an ongoing concern. The current focus is on specific manifestations such as bullying, but the behavior is broad and heterogenous. Children spend a substantial amount of time in school, but their behaviors in the school setting tend to be less well characterized than at home. Because aggression may index multiple behavioral problems, we used three validated instruments to assess means, correlations and gender differences of teacher-rated aggressive behavior with co-occurring externalizing/internalizing problems and social behavior in 39,936 schoolchildren aged 7-14 from 4 population-based cohorts from Finland, the Netherlands, and the UK. Correlations of aggressive behavior were high with all other externalizing problems (r: 0.47-0.80) and lower with internalizing problems (r: 0.02-0.39). A negative association was observed with prosocial behavior (r: -0.33 to -0.54). Mean levels of aggressive behavior differed significantly by gender. Despite the higher mean levels of aggressive behavior in boys, the correlations were notably similar for boys and girls (e.g., aggressive-hyperactivity correlations: 0.51-0.75 boys, 0.47-0.70 girls) and did not vary greatly with respect to age, instrument or cohort. Thus, teacher-rated aggressive behavior rarely occurs in isolation; boys and girls with problems of aggressive behavior likely require help with other behavioral and emotional problems. Important to note, higher aggressive behavior is not only associated with higher amounts of other externalizing and internalizing problems but also with lower levels of prosocial behavior.

Genome-wide association meta-analysis of nicotine metabolism and cigarette consumption measures in smokers of European descent.

Smoking behaviors, including amount smoked, smoking cessation, and tobacco-related diseases, are altered by the rate of nicotine clearance. Nicotine clearance can be estimated using the nicotine metabolite ratio (NMR) (ratio of 3'hydroxycotinine/cotinine), but only in current smokers. Advancing the genomics of this highly heritable biomarker of CYP2A6, the main metabolic enzyme for nicotine, will also enable investigation of never and former smokers. We performed the largest genome-wide association study (GWAS) to date of the NMR in European ancestry current smokers (n = 5185), found 1255 genome-wide significant variants, and replicated the chromosome 19 locus. Fine-mapping of chromosome 19 revealed 13 putatively causal variants, with nine of these being highly putatively causal and mapping to CYP2A6, MAP3K10, ADCK4, and CYP2B6. We also identified a putatively causal variant on chromosome 4 mapping to TMPRSS11E and demonstrated an association between TMPRSS11E variation and a UGT2B17 activity phenotype. Together the 14 putatively causal SNPs explained ~38% of NMR variation, a substantial increase from the ~20 to 30% previously explained. Our additional GWASs of nicotine intake biomarkers showed that cotinine and smoking intensity (cotinine/cigarettes per day (CPD)) shared chromosome 19 and chromosome 4 loci with the NMR, and that cotinine and a more accurate biomarker, cotinine + 3'hydroxycotinine, shared a chromosome 15 locus near CHRNA5 with CPD and Pack-Years (i.e., cumulative exposure). Understanding the genetic factors influencing smoking-related traits facilitates epidemiological studies of smoking and disease, as well as assists in optimizing smoking cessation support, which in turn will reduce the enormous personal and societal costs associated with smoking.

Higher aggression is related to poorer academic performance in compulsory education.

BACKGROUND: To conduct a comprehensive assessment of the association between aggression and academic performance in compulsory education. METHOD: We studied aggression and academic performance in over 27,000 individuals from four European twin cohorts participating in the ACTION consortium (Aggression in Children: Unraveling gene-environment interplay to inform Treatment and InterventiON strategies). Individual level data on aggression at ages 7-16 were assessed by three instruments (Achenbach System of Empirically Based Assessment, Multidimensional Peer Nomination Inventory, Strengths and Difficulties Questionnaire) including parental, teacher and self-reports. Academic performance was measured with teacher-rated grade point averages (ages 12-14) or standardized test scores (ages 12-16). Random effect meta-analytical correlations with academic performance were estimated for parental ratings (in all four cohorts) and self-ratings (in three cohorts). RESULTS: All between-family analyses indicated significant negative aggression-academic performance associations with correlations ranging from -.06 to -.33. Results were similar across different ages, instruments and raters and either with teacher-rated grade point averages or standardized test scores as measures of academic performance. Meta-analytical r's were -.20 and -.23 for parental and self-ratings, respectively. In within-family analyses of all twin pairs, the negative aggression-academic performance associations were statistically significant in 14 out of 17 analyses (r = -.17 for parental- and r = -.16 for self-ratings). Separate analyses in monozygotic (r = -.07 for parental and self-ratings), same-sex dizygotic (r's = -.16 and -.17 for parental and self-ratings) and opposite-sex dizygotic (r's = -.21 and -.19 for parental and self-ratings) twin pairs suggested partial confounding by genetic effects. CONCLUSIONS: There is a robust negative association between aggression and academic performance in compulsory education. Part of these associations were explained by shared genetic effects, but some evidence of a negative association between aggression and academic performance remained even in within-family analyses of monozygotic twin pairs.

Associations of Alcohol Consumption With Epigenome-Wide DNA Methylation and Epigenetic Age Acceleration: Individual-Level and Co-twin Comparison Analyses.

BACKGROUND: DNA methylation may play a role in the progression from normative to problematic drinking and underlie adverse health outcomes associated with alcohol misuse. We examined the association between alcohol consumption and DNA methylation patterns using 3 approaches: a conventional epigenome-wide association study (EWAS); a co-twin comparison design, which controls for genetic and environmental influences that twins share; and a regression of age acceleration, defined as a discrepancy between chronological age and DNA methylation age, on alcohol consumption. METHODS: Participants came from the Finnish Twin Cohorts (FinnTwin12/FinnTwin16; N = 1,004; 55% female; average age = 23 years). Individuals reported the number of alcoholic beverages consumed in the past week, and epigenome-wide DNA methylation was assessed in whole blood using the Infinium HumanMethylation450 BeadChip. RESULTS: In the EWAS, alcohol consumption was significantly related to methylation at 24 CpG sites. When evaluating whether differences between twin siblings (185 monozygotic pairs) in alcohol consumption predicted differences in DNA methylation, co-twin comparisons replicated 4 CpG sites from the EWAS and identified 23 additional sites. However, when we examined qualitative differences in drinking patterns between twins (heavy drinker vs. light drinker/abstainer or moderate drinker vs. abstainer; 44 pairs), methylation patterns did not significantly differ within twin pairs. Finally, individuals who reported higher alcohol consumption also exhibited greater age acceleration, though results were no longer significant after controlling for genetic and environmental influences shared by co-twins. CONCLUSIONS: Our analyses offer insight into the associations between epigenetic variation and levels of alcohol consumption in young adulthood.