Screen time and early adolescent mental health, academic, and social outcomes in 9- and 10- year old children: Utilizing the Adolescent Brain Cognitive Development ℠ (ABCD) Study.

In a technology-driven society, screens are being used more than ever. The high rate of electronic media use among children and adolescents begs the question: is screen time harming our youth? The current study draws from a nationwide sample of 11,875 participants in the United States, aged 9 to 10 years, from the Adolescent Brain Cognitive Development Study (ABCD Study®). We investigate relationships between screen time and mental health, behavioral problems, academic performance, sleep habits, and peer relationships by conducting a series of correlation and regression analyses, controlling for SES and race/ethnicity.

Genetic and environmental influences on executive functions and intelligence in middle childhood.

Executive functions (EFs) and intelligence (IQ) are phenotypically correlated. In twin studies, latent variables for EFs and IQ display moderate to high heritability estimates; however, they show variable genetic correlations in twin studies spanning childhood to middle age. We analyzed data from over 11,000 children (9- to 10-year-olds, including 749 twin pairs) in the Adolescent Brain Cognitive Development (ABCD) Study to examine the phenotypic and genetic relations between EFs and IQ in childhood.

Investigating the causal effect of cannabis use on cognitive function with a quasi-experimental co-twin design.

Background: It is unclear whether cannabis use causes cognitive decline; several studies show an association between cannabis use and cognitive decline, but quasi-experimental twin studies have found little support for a causal effect. Here, we evaluate the association of cannabis use with general cognitive ability and executive functions (EFs) while controlling for genetic and shared environmental confounds in a longitudinal twin study.

Methods: We first examined the phenotypic associations between cannabis initiation, frequency, and use disorder with cognitive abilities, while also controlling for pre-use general cognitive ability and other substance involvement.

The role of genetic and environmental influences on the association between childhood ADHD symptoms and BMI.

Background/objectives: Although childhood attention deficit hyperactivity disorder (ADHD) has been previously associated with concurrent and later obesity in adulthood, the etiology of this association remains unclear. The objective of this study is to determine the shared genetic effects of ADHD symptoms and BMI in a large sample of sibling pairs, consider how these shared effects may vary over time, and examine potential sex differences.

Subject/methods: Sibling pair data were obtained from the National Longitudinal Study of Adolescent to Adult Health (Add Health); childhood ADHD symptoms were reported retrospectively during young adulthood, while three prospective measurements of BMI were available from young adulthood to later adulthood.

Simple sequence repeats in the national longitudinal study of adolescent health: an ethnically diverse resource for genetic analysis of health and behavior.

Simple sequence repeats (SSRs) are one of the earliest available forms of genetic variation available for analysis and have been utilized in studies of neurological, behavioral, and health phenotypes. Although findings from these studies have been suggestive, their interpretation has been complicated by a variety of factors including, among others, limited power due to small sample sizes. The current report details the availability, diversity, and allele and genotype frequencies of six commonly examined SSRs in the ethnically diverse, population-based National Longitudinal Study of Adolescent Health.

Prevalence and correlates of alcohol and cannabis use disorders in the United States: results from the national longitudinal study of adolescent health.

Background: Limited current information on the epidemiology of lifetime alcohol and cannabis use disorders in the United States is available.

Aims: To present detailed information about the prevalence and sociodemographic correlates of lifetime alcohol and cannabis use disorders rates in the United States. To examine gender differences in hazard ratios for the onset of alcohol and cannabis dependence.

MAOA genotype, childhood maltreatment, and their interaction in the etiology of adult antisocial behaviors.

Background: Maltreatment by an adult or caregiver during childhood is a prevalent and important predictor of antisocial behaviors in adulthood. A functional promoter polymorphism in the monoamine oxidase A (MAOA) gene has been implicated as a moderating factor in the relationship between childhood maltreatment and antisocial behaviors. Although there have been numerous attempts at replicating this observation, results remain inconclusive.

The CHRNA5/A3/B4 gene cluster and tobacco, alcohol, cannabis, inhalants and other substance use initiation: replication and new findings using mixture analyses.

Multiple studies have provided evidence for genetic associations between single nucleotide polymorphisms (SNPs) located on the CHRNA5/A3/B4 gene cluster and various phenotypes related to Nicotine Dependence (Greenbaum et al. 2009). Only a few studies have investigated other substances of abuse.

Dizziness and the genetic influences on subjective experiences to initial cigarette use.

Aim: To examine individual differences in positive and negative subjective experiences to initial cigarette use.

Design: Retrospective self-reports of initial subjective experiences were examined to estimate the genetic and environmental influences and the extent of their covariation across different effects.

Participants: Data was drawn from 2482 young adult same-and opposite sex twins- and siblings participating in the National Longitudinal Study of Adolescent Health.

The association between conduct problems and maltreatment: testing genetic and environmental mediation.

It is often assumed that childhood maltreatment causes conduct problems via an environmentally mediated process. However, the association may be due alternatively to either a nonpassive gene-environment correlation, in which parents react to children's genetically-influenced conduct problems by maltreating them, or a passive gene-environment correlation, in which parents' tendency to engage in maltreatment and children's conduct problems are both influenced by a hereditary vulnerability to antisocial behavior (i.e.

Investigation of genetically mediated child effects on maltreatment.

Theory and empirical evidence suggest that children's genetically influenced characteristics help to shape the environments they experience, including the parenting they 'receive'. The extent of these genetically-mediated child effects on childhood maltreatment is not well known. The present study estimates the magnitude of genetically mediated child effects on maltreatment in 3,297 twins and siblings who were part of a large nationally representative sample of adolescents (ADD health).

The CHRNA5/A3/B4 gene cluster variability as an important determinant of early alcohol and tobacco initiation in young adults.

Background: One potential site of convergence of the nicotine and alcohol actions is the family of the neuronal nicotinic acetylcholine receptors. Our study examines the genetic association between variations in the genomic region containing the CHRNA5, A3, and B4 gene cluster (A5A3B4) and several phenotypes of alcohol and tobacco use in an ethnically diverse young adult sample. Significant results were then replicated in a separate adult population-representative sample.

College attendance and its effect on drinking behaviors in a longitudinal study of adolescents.

Background: While college attendance has been shown to be associated with increased drinking behaviors, there are no studies to our knowledge that have examined whether college attendance moderates genetic influences for drinking. We first tested for changes in alcohol consumption in adolescents who did and did not subsequently attend college, and then tested for variation of the genetic and environmental determinants of drinking in these 2 groups.

Methods: Participants eligible for this study were selected from 2 samples from the National Longitudinal Study of Adolescent Health (Add Health), a national probability sample (n=7,083) and a sample of sibling pairs (n=855 pairs).

Genes, time to first cigarette and nicotine dependence in a general population sample of young adults.

Aim: To examine variation in nicotine dependence scores and covariation between different dependence symptoms.

Design: A 12-year, nationally representative, probability-based survey of adolescent health-related behaviors and their outcomes during young adulthood in the United States. The genetic contribution to nicotine dependence was evaluated in the sibling-pairs sample of the US National Longitudinal Study of Adolescent Health.

Progression from marijuana use to daily smoking and nicotine dependence in a national sample of U.S. adolescents.

Background: While it has been demonstrated that smoking cigarettes in adolescence increases the likelihood of progressing to marijuana use, few studies have considered the reverse scenario in which early use of cannabis leads to greater tobacco smoking.

Methods: Participants (n=5963), who had never smoked cigarettes daily by wave I of the National Longitudinal Study of Adolescent Health, were followed 6 years (waves I-III) from adolescence into young adulthood. Measures of marijuana use (lifetime use, monthly use, age at first use), as assessed at wave I within 12-16 (n=3712) and 17-21 (n=2251) year-olds, were separately modeled as predictors of three tobacco-related outcomes: (1) age at onset of daily cigarette smoking, (2) lifetime nicotine dependence, (3) current nicotine dependence.

A genome-wide scan for loci influencing adolescent cannabis dependence symptoms: evidence for linkage on chromosomes 3 and 9.

Objective: Cannabis is the most frequently abused illicit substance among adolescents and young adults. Genetic risk factors account for part of the variation in the development of cannabis dependence symptoms; however, no linkage studies have been performed for cannabis dependence symptoms. This study aimed to identify such loci.

The family transmission of adolescent alcohol abuse and dependence.

Objective: This study examines the familial transmission of alcohol abuse and dependence to adolescents.

Method: Male adolescents recruited from a treatment program for substance problems, matched controls, and all available biological parents and siblings were assessed with a structured psychiatric interview assessing Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, based diagnoses of alcohol abuse and alcohol dependence. A total of 2,612 individuals from 911 families were interviewed.

An association between the DAT1 polymorphism and smoking behavior in young adults from the National Longitudinal Study of Adolescent Health.

Associations between smoking behavior and polymorphisms in the dopaminergic genes (DAT1 and DRD2) were tested by using within- and between-family measures of allelic transmission in 2,448 young adults from the National Longitudinal Study of Adolescent Health. The 9-repeat allele of the dopamine transporter gene polymorphism (DAT1) was inversely associated with smoking in samples that included all subjects and only those who had initiated smoking, accounting for approximately 1% of the variance. Never smokers and current nonsmokers had an excess transmission of the 9-repeat allele compared with regular smokers, suggesting a protective effect of the 9-repeat allele, which is hypothesized to alter synaptic dopamine levels.

Relationship between adolescent marijuana use and young adult illicit drug use.

: We examined three components of the "gateway theory" in relation to marijuana use: (1) whether adolescent marijuana use predicts young adult drug use, (2) whether this association persists when controlling for similar family background, (3) whether common genetic or environmental factors contribute to the association. The three components were tested in adolescents from the National Longitudinal Study of Adolescent Health assessed twice during adolescence and then re-interviewed 5 years later. Component 1 was tested in 18,286 subjects, component 2 in sibling pairs (n=360) discordant for marijuana use, and component 3 in a genetically informative sub-sample (n=4846).

The moderating effects of religiosity on the genetic and environmental determinants of smoking initiation.

Although a number of studies have shown that various measures of religiosity are inversely correlated with smoking behavior, none of these studies have used genetically informative samples to test for a gene-environment interaction between the determinants of smoking initiation and religiosity. We tested the moderating effects of three measures of religiosity (religious affiliation, organizational religious activity, and self-rated religiousness) on the genetic and environmental determinants of smoking initiation in 237 monozygotic twin pairs, 315 dizygotic twin pairs, 779 full-sibling pairs, and 233 half-sibling pairs in young adults surveyed from the third wave of the National Longitudinal Study of Adolescent Health. Primary analyses incorporated all sibling pairs, irrespective of whether they were concordant or discordant for the environmental moderator, in models designed to account for the confounding effects of a gene-environment correlation.

A genome-wide search for quantitative trait Loci that influence antisocial drug dependence in adolescence.

Background: Among adolescents, externalizing problem behavior and substance use disorders are often comorbid. Familial influences, including shared genetic risk factors, may account for part of this comorbidity. Previously we reported 2 chromosomal regions (3q24-3q25 and 9q34) likely to contain genes that influence substance dependence vulnerability (DV) in adolescence.

Genetic influences on quantity of alcohol consumed by adolescents and young adults.

Objective: To examine genetic and environmental influences on drinking in a nationally representative study of genetically informative adolescents followed into young adulthood.

Method: The average quantity of alcohol used per drinking episode during the past year was analyzed in 4432 youth assessed during adolescence (mean age of 16) and then 1 and 6 years later. The variance of quantity of alcohol consumed was decomposed into three components: additive genetic (a2), shared environmental (c2), non-shared environmental (e2).

Monoamine oxidase A (MAOA) and antisocial behaviors in the presence of childhood and adolescent maltreatment.

There is a robust relationship between the experience of maltreatment in childhood and later antisocial behaviors amongst adolescents and adults. Animal and human studies suggest that variation in monoamine oxidase A (MAOA) genotype may moderate the effects of maltreatment. Self-reported conduct problems and criminal convictions amongst sibling-pairs from the National Longitudinal Study of Adolescent Health were tested for association with reports of maltreatment before and after the age of 12.

The validity of the Neale and Kendler model-fitting approach in examining the etiology of comorbidity.

Given that knowledge regarding the etiology of comorbidity between disorders can have a significant impact on research regarding the classification, treatment, and etiology of the disorders, the ability to reject incorrect hypotheses regarding the causes of comorbidity is very important. A simulation study was conducted to assess the validity of the Neale and Kendler (1995) model-fitting approach in examining the etiology of comorbidity between two disorders. First, data were simulated under the assumptions of the 13 alternative comorbidity models described by Neale and Kendler.

A genome-wide search for quantitative trait loci influencing substance dependence vulnerability in adolescence.

This study describes results from a genome-wide search for quantitative trait loci (QTL) influencing substance dependence vulnerability in adolescence. We utilized regression-based multipoint (and single-point) QTL mapping procedures designed for selected sibpair samples. Selected sibling pairs included 250 proband-sibling pairs from 192 families.