The Adolescent Brain Cognitive Development (ABCD) Study, a large, longitudinal study of brain development and child health, relies on the engagement of communities, educators, and families to ensure its success. To that end, community and partner relationships, development of targeted messages and materials for specific audiences (educators, families, youth, scientists), and continued and consistent outreach must be an integral part of the Consortium activities. The ABCD Consortium has made these efforts a priority and developed a framework to raise awareness about the study and promote sustained broad-base support from diverse stakeholders.
Recruiting the ABCD Sample: Design Considerations and Procedures
The ABCD study is a new and ongoing project of very substantial size and scale involving 21 data acquisition sites. It aims to recruit 11,500 children and follow them for ten years with extensive assessments at multiple timepoints. To deliver on its potential to adequately describe adolescent development, it is essential that it adopt recruitment procedures that are efficient and effective and will yield a sample that reflects the nation’s diversity in an epidemiologically informed manner. Here, we describe the sampling plans and recruitment procedures of this study. Participants are largely recruited through the school systems with school selection informed by gender, race and ethnicity, socioeconomic status, and urbanicity. Procedures for school selection designed to mitigate selection biases, dynamic monitoring of the accumulating sample to correct deviations from recruitment targets, and a description of the recruitment procedures designed to foster a collaborative attitude between the researchers, the schools and the local communities, are provided.
A description of the ABCD organizational structure and communication framework
The Adolescent Brain Cognitive Development (ABCD) study is designed to be the largest study of brain development and child health in the United States, performing comprehensive assessments of 11,500 children repeatedly for 10 years. An endeavor of this magnitude requires an organized framework of governance and communication that promotes collaborative decision-making and dissemination of information. The ABCD consortium structure, built upon the Matrix Management approach of organizational theory, facilitates the integration of input from all institutions, numerous internal workgroups and committees, federal partners, and external advisory groups to make use of a broad range of expertise to ensure the study’s success.
A brief validated screen to identify boys and girls at risk for early marijuana use
To guide recruitment, the ABCD Study requires a method for identifying children at high risk for early-onset substance use that may be utilized during the recruitment process. This study was undertaken to inform the development of a brief screen for identifying youths’ risk of early-onset substance use and other adverse outcomes. To be acceptable by participants in this context, consideration of potential items was limited to child characteristics previously determined to be potentially pertinent and parental cigarette smoking. To focus the analyses on a single target substance use outcome pertinent to the stated goals of the ABCD Study, early-onset marijuana use was selected. Utilizing data collected prior to the initiation of the ABCD Study, four longitudinal data sets were used in nine secondary data analyses to test, replicate and validate a brief screening assessment for boys and girls to identify those at risk for early-onset marijuana use by ages 14–15. The combination of child externalizing problems reported by the parent (4 items: destroys things belonging to his/her family or others; disobedience at school; lying or cheating; steals outside the home) and parent smoking (1 item) proved to be the optimal screen. This was largely replicated across the four data sets. Indicators of predictive efficiency were modest in magnitude and statistically significant in 8 out of the 9 analyses. The results informed the screen’s optimal threshold for identifying children at risk for early-onset marijuana use. The addition of child internalizing problems did not improve these predictions. Further analyses showed the predictive utility of the screen for several other substance use outcomes at ages 15 to 18, including alcohol and nicotine use. The results support the use of a short screening assessment to identify youth at risk for early-onset substance use in the ABCD Study and other research.
Current, future and potential use of mobile and wearable technologies andsocial media data in the ABCD study to increase understanding of contributors to child health
Mobile and wearable technologies and novel methods of data collection are innovating health-related research. These technologies and methods allow for multi-system level capture of data across environmental, physiological, behavioral, and psychological domains. In the Adolescent Brain Cognitive Development (ABCD) Study, there is great potential for harnessing the acceptability, accessibility, and functionality of mobile and social technologies for in-vivo data capture to precisely measure factors, and interactions between factors, that contribute to childhood and adolescent neurodevelopment and psychosocial and health outcomes. Here we discuss advances in mobile and wearable technologies and methods of analysis of geospatial, ecologic, social network and behavioral data. Incorporating these technologies into the ABCD study will allow for interdisciplinary research on the effects of place, social interactions, environment, and substance use on health and developmental outcomes in children and adolescents.
Assessment of culture and environment in the Adolescent Brain and Cognitive Development Study: Rationale, description of measures, and early data
Neurodevelopmental maturation takes place in a social environment in addition to a neurobiological one. Characterization of social environmental factors that influence this process is therefore an essential component in developing an accurate model of adolescent brain and neurocognitive development, as well as susceptibility to change with the use of marijuana and other drugs. The creation of the Culture and Environment (CE) measurement component of the ABCD protocol was guided by this understanding. Three areas were identified by the CE Work Group as central to this process: influences relating to CE Group membership, influences created by the proximal social environment, influences stemming from social interactions. Eleven measures assess these influences, and by time of publication, will have been administered to well over 7,000 9–10 year-old children and one of their parents. Our report presents baseline data on psychometric characteristics (mean, standard deviation, range, skewness, coefficient alpha) of all measures within the battery. Effectiveness of the battery in differentiating 9–10-year olds who were classified as at higher and lower risk for marijuana use in adolescence was also evaluated. Psychometric characteristics on all measures were good to excellent; higher vs. lower risk contrasts were significant in areas where risk differentiation would be anticipated.
Biospecimens and the ABCD study: Rationale, methods of collection, measurement and early data
Biospecimen collection in the Adolescent Brain Cognitive Development (ABCD) study – of hair samples, shed deciduous (baby) teeth, and body fluids – will serve dual functions of screening for study eligibility, and providing measures of biological processes thought to predict or correlate with key study outcomes on brain and cognitive development. Biosamples are being collected annually to screen for recency of drug use prior to the neuroimaging or cognitive testing visit, and to store for the following future studies: (1) on the effects of exposure to illicit and recreational drugs (including alcohol and nicotine); (2) of pubertal hormones on brain and cognitive developmental trajectories; (3) on the contribution of genomics and epigenomics to child and adolescent development and behavioral outcomes; and (4) with pre- and post-natal exposure to environmental neurotoxicants and drugs of abuse measured from novel tooth analyses. The present manuscript describes the rationales for inclusion and selection of the specific biospecimens, methodological considerations for each measure, future plans for assessment of biospecimens during follow-up visits, and preliminary ABCD data to illustrate methodological considerations.
The Adolescent Brain Cognitive Development (ABCD) study: Imaging acquisition across 21 sites
The ABCD study is recruiting and following the brain development and health of over 10,000 9–10 year olds through adolescence. The imaging component of the study was developed by the ABCD Data Analysis and Informatics Center (DAIC) and the ABCD Imaging Acquisition Workgroup. Imaging methods and assessments were selected, optimized and harmonized across all 21 sites to measure brain structure and function relevant to adolescent development and addiction. This article provides an overview of the imaging procedures of the ABCD study, the basis for their selection and preliminary quality assurance and results that provide evidence for the feasibility and age-appropriateness of procedures and generalizability of findings to the existent literature.
Adolescent neurocognitive development and impacts of substance use: Overview of the adolescent brain cognitive development (ABCD) baseline neurocognition battery
Adolescence is characterized by numerous social, hormonal and physical changes, as well as a marked increase in risk-taking behaviors. Dual systems models attribute adolescent risk-taking to tensions between developing capacities for cognitive control and motivational strivings, which may peak at this time. A comprehensive understanding of neurocognitive development during the adolescent period is necessary to permit the distinction between premorbid vulnerabilities and consequences of behaviors such as substance use. Thus, the prospective assessment of cognitive development is fundamental to the aims of the newly launched Adolescent Brain and Cognitive Development (ABCD) Consortium. This paper details the rationale for ABC’lected measures of neurocognition, presents preliminary descriptive data on an initial sample of 2299 participants, and provides a context for how this large-scale project can inform our understanding of adolescent neurodevelopment.
Adolescent brain cognitive development (ABCD) study: Overview of substance use assessment methods
One of the objectives of the Adolescent Brain Cognitive Development (ABCD) Study (https://abcdstudy.org/) is to establish a national longitudinal cohort of 9 and 10 year olds that will be followed for 10 years in order to prospectively study the risk and protective factors influencing substance use and its consequences, examine the impact of substance use on neurocognitive, health and psychosocial outcomes, and to understand the relationship between substance use and psychopathology. This article provides an overview of the ABCD Study Substance Use Workgroup, provides the goals for the workgroup, rationale for the substance use battery, and includes details on the substance use module methods and measurement tools used during baseline, 6-month and 1-year follow-up assessment time-points. Prospective, longitudinal assessment of these substance use domains over a period of ten years in a nationwide sample of youth presents an unprecedented opportunity to further understand the timing and interactive relationships between substance use and neurocognitive, health, and psychopathology outcomes in youth living in the United States.
The Adolescent Brain Cognitive Development (ABCD) Study is a longitudinal, observational study of over 10,000 youth recruited at 21 sites throughout the United States. Comprehensive biennial assessments and more limited interim assessments measure health, mental health, neurocognition, family, cultural and environmental variables, substance use, genetic and other biomarkers, and structural and functional brain development. Within this Special Issue, readers will find much information about the rationale and objectives of the study, the broad ranging assessment protocols and new as well as traditional methodologies applied at baseline, the recruitment and retention strategies, and the anticipated final composition of the cohort. Information is also provided about how the study is coordinated and conducted, how decisions are made, how data quality is monitored, and how ethical standards are protected. In this introduction we will focus instead on the position of the ABCD Study in the changing landscape of biomedical research.
The adolescent brain cognitive development study external advisory board
Why should the Adolescent Brain Cognitive Development study (ABCD Study) have an External Advisory Board (EAB)? ABCD Study has approximately two-dozen principal investigators, all experts and leaders in the diverse fields of study required to accomplish ABCD Study’s goals. Furthermore, as part of an NIH consortium, ABCD Study investigators work in close collaboration with scientific experts from multiple National Institutes of Health (NIH) Institutes and Offices (https://abcdstudy.org/federal-partners.html) and have ready access to their expertise. And NIH has constituted an Observational Study Management Board (OSMB) to offer oversight and counsel to ABCD Study regarding myriad ethical issues that might arise in the course of a 10-year longitudinal study of 10,000 children. So why also have an EAB? In a way, it is the organizational structure of ABCD Study, its cost, its complexity, its extraordinarily ambitious goals, and its importance to the scientific community and public health that together obligate oversight from an unbiased set of experts who can advise ABCD Study across a wide range of issues.
Retention efforts are critical to maintain relationships with research participants over time. This is especially important for the Adolescent Brain Cognitive Development (ABCD) study, where families are asked to stay engaged with the study throughout the course of 10 years. This high-degree of involvement is essential to longitudinally track child and adolescent development. At a minimum, we will connect with families every 6 months by telephone, and every year in person, with closer contact with the youth directly as they transition into adolescence. Differential retention, when related to non-random issues pertaining to demographic or risk features, can negatively impact the generalizability of study outcomes. Thus, to ensure high rates of retention for all participants, the ABCD study employs a number of efforts to support youth and families. This overview details the framework and concrete steps for retention.
Demographic, physical and mental health assessments in the adolescent brain and cognitive development study: Rationale and description
The Adolescent Brain and Cognitive Development (ABCD) Study incorporates a comprehensive range of measures assessing predictors and outcomes related to both mental and physical health across childhood and adolescence. The workgroup developed a battery that would assess a comprehensive range of domains that address study aims while minimizing participant and family burden. We review the major considerations that went into deciding what constructs to cover in the demographics, physical health and mental health domains, as well as the process of selecting measures, piloting and refining the originally proposed battery. We present a description of the baseline battery, as well as the six-month interim assessments and the one-year follow-up assessments. This battery includes assessments from the perspectives of both the parent and the target youth, as well as teacher reports. This battery will provide a foundational baseline assessment of the youth’s current function so as to permit characterization of stability and change in key domains over time. The findings from this battery will also be utilized to identify both resilience markers that predict healthy development and risk factors for later adverse outcomes in physical health, mental health, and substance use and abuse.
The conception of the ABCD study: From substance use to a broad NIH collaboration
Adolescence is a time of dramatic changes in brain structure and function, and the adolescent brain is highly susceptible to being altered by experiences like substance use. However, there is much we have yet to learn about how these experiences influence brain development, how they promote or interfere with later health outcomes, or even what healthy brain development looks like. A large longitudinal study beginning in early adolescence could help us understand the normal variability in adolescent brain and cognitive development and tease apart the many factors that influence it. Recent advances in neuroimaging, informatics, and genetics technologies have made it feasible to conduct a study of sufficient size and scope to answer many outstanding questions. At the same time, several Institutes across the NIH recognized the value of collaborating in such a project because of its ability to address the role of biological, environmental, and behavioral factors like gender, pubertal hormones, sports participation, and social/economic disparities on brain development as well as their association with the emergence and progression of substance use and mental illness including suicide risk. Thus, the Adolescent Brain Cognitive Development study was created to answer the most pressing public health questions of our day.
The utility of twins in developmental cognitive neuroscience research: How twins strengthen the ABCD research design
The ABCD twin study will elucidate the genetic and environmental contributions to a wide range of mental and physical health outcomes in children, including substance use, brain and behavioral development, and their interrelationship. Comparisons within and between monozygotic and dizygotic twin pairs, further powered by multiple assessments, provide information about genetic and environmental contributions to developmental associations, and enable stronger tests of causal hypotheses, than do comparisons involving unrelated children. Thus a sub-study of 800 pairs of same-sex twins was embedded within the overall Adolescent Brain and Cognitive Development (ABCD) design. The ABCD Twin Hub comprises four leading centers for twin research in Minnesota, Colorado, Virginia, and Missouri. Each site is enrolling 200 twin pairs, as well as singletons. The twins are recruited from registries of all twin births in each State during 2006–2008. Singletons at each site are recruited following the same school-based procedures as the rest of the ABCD study. This paper describes the background and rationale for the ABCD twin study, the ascertainment of twin pairs and implementation strategy at each site, and the details of the proposed analytic strategies to quantify genetic and environmental influences and test hypotheses critical to the aims of the ABCD study.
Biomedical ethics and clinical oversight in multisite observational neuroimaging studies with children and adolescents: The ABCD experience
Observational neuroimaging studies with children and adolescents may identify neurological anomalies and other clinically relevant findings. Planning for the management of this information involves ethical considerations that may influence informed consent, confidentiality, and communication with participants about assessment results. Biomedical ethics principles include respect for autonomy, beneficence, non-maleficence, and justice. Each project presents unique challenges. The Adolescent Brain and Cognitive Development study (ABCD) collaborators have systematically developed recommendations with written guidelines for identifying and responding to potential risks that adhere to biomedical ethics principles. To illustrate, we will review the ABCD approach to three areas: (1) hazardous substance use; (2) neurological anomalies; and (3) imminent potential for self-harm or harm to others. Each ABCD site is responsible for implementing procedures consistent with these guidelines in accordance with their Institutional Review Board approved protocols, state regulations, and local resources. To assure that each site has related plans and resources in place, site emergency procedures manuals have been developed, documented and reviewed for adherence to ABCD guidelines. This article will describe the principles and process used to develop these ABCD bioethics and medical oversight guidelines, the concerns and options considered, and the resulting approaches advised to sites.