By Nora Volkow (Director, NIDA), George Koob (Director, NIAAA), Alan Guttmacher (Director, NICHD), Bob Croyle (Director, Division of Cancer Control and Population Sciences, NCI), Thomas Insel (Director, NIMH), and William Riley (Director, OBSSR).
Today the Adolescent Brain Cognitive Development (ABCD) Study officially gets underway, as the National Institutes of Health award 13 five-year grants to U.S. research institutions that will spearhead the landmark project over the first half of its roughly 10-year duration. Researchers at these institutions will follow approximately 10,000 children, recruited initially at age 9 or 10 (i.e., before they are likely to have started using drugs), conducting behavioral interviews and gathering neuroimaging, genetic, and other health data at periodic intervals until they are young adults. The data gathered will enable researchers to assess the effects of different patterns of alcohol, tobacco, and drug use (including no use) on the developing brain, on mental health, and on outcomes like academic achievement, as well as a wide range of other factors affecting young Americans' life and health.
The teen years are the period of highest risk for substance use and for the development of other behavioral disorders, and they are also a period when the brain is changing dramatically. A study of this scope will yield an unprecedented amount of detailed information about how the brain develops and how its development is affected by a multitude of factors alone and in combination with each other. It will allow us to look not only at exposure to substances including nicotine, alcohol, and marijuana and other drugs but also at mental illnesses, the effects of brain traumas from injuries, and influences of other environmental factors like family and peer influences, and socioeconomic status. The inclusion of genetic data will give us crucial information about genes' influence on adolescent development and on vulnerability to mental illness and the effects of substance use.
The study will do much to fill the large existing gaps in our knowledge about the brain-developmental effects of many substances. Current high levels of underage binge drinking and increased intensity of binge drinking in adolescents are causes of significant concern, for example, and this study will clarify how various levels of alcohol exposure, as well as alcohol use in combination with other substances, affect the developing brain. Given the changing laws around marijuana in some states that will likely make this drug more accessible to youth, a similarly nuanced picture of marijuana's effects is also crucial to acquire. Although cigarette use among adolescents has declined, the surge in use of e-cigarettes (which deliver nicotine and other chemicals to the user) and other tobacco products like little cigars, makes it very important to learn more about the impact of nicotine and tobacco use on the adolescent brain, including how their use affects the brain's response to other drugs. The ABCD study will also provide crucial insight into the developmental effects of new synthetic cannabinoids ("herbal incense") and synthetic cathinones (or bath salts), about which we have practically no knowledge at this point.
The large number of teens that the ABCD study hopes to recruit and retain for its decade-long duration will not just yield vast amounts of data on the effects of substance use but will also greatly clarify our picture of normal healthy brain development. It is important to remember that most young people never develop drug or alcohol problems, and only about half use an illicit drug before leaving high school. High-risk groups will be oversampled in order to ensure that enough data on substance users are collected. But the ABCD study data on typically developing, healthy adolescents with minimal or no substance use exposure will also be extremely valuable for comparison, both in this and future studies. These data will be a great contribution to science, as currently no normal imaging standards for adolescents exist to enable researchers to make such comparisons.
The 13 grants issued today will fund a Coordinating Center, a Data Analysis and Informatics Center, and 11 research project sites. It is an exciting moment for addiction research. A decade from now, we will understand the effects of substance use on development with a precision that, today, we can barely imagine.