A Light Into the Adolescent Brain: Landmark Study to Explore Impact of Substance Use on America’s Youth

Today’s teens and tweens have greater access to marijuana, in higher potencies, than ever before. They also use more alcohol when they binge drink, and puff e-cigarettes that deliver candy-coated nicotine vapors.

How will these substances affect the brains of America’s youth? Can occasional drug use alter the course of adolescent development? What’s the link between alcohol or drug use and mental illness?

These are among the pressing questions being explored in a landmark study now underway. The Adolescent Brain Cognitive Development (ABCD) study will track 10,000 American children, beginning at ages nine to 10, when they are at low risk for drug use, and follow them for a decade into young adulthood.

Researchers will primarily study normal brain development and ways that adolescent behavior and risk factors – such as substance use, trauma, medical and mental health problems – can modify young brains.

“The size and comprehensiveness of this study is unprecedented,” says Sandra Brown, Ph.D., Vice Chancellor for Research and Distinguished Professor of Psychology and Psychiatry at the University of California, San Diego (UCSD).

Brown emphasizes that the ABCD study will enlist a broad segment of America’s youth, the vast majority of whom will not have or develop drug problems. But the large population sample may help scientists unravel how substances such as nicotine, alcohol and marijuana – alone or in combination – affect the developing brain.

“Substance use commonly begins in the adolescent years and yet, most of what we know about the impact of substances is based on adults,” Brown says. “ABCD will provide information on normal development during the adolescent years as well as insights into, risks for, and consequences of early experience with substances.”

UCSD will oversee the big data study, initiated and funded by the National Institutes of Health. Brown serves as Co-Director of the ABCD Coordinating Center, along with Terry Jernigan, Ph.D., Professor of Cognitive Science, Psychiatry and Radiology and Director of the Center for Human Development at UCSD.

“We are fortunate to have top addiction scientists working with us from 20 research settings around the United States – all the way from Vermont to Hawaii,” Brown says. “We will establish a data set that our group and others from around the world will be able to access and analyze on an ongoing basis . . . rather than waiting for all reports at the end of the study.”

Studies show that adolescence is the period of highest risk for the onset of drug and alcohol problems. It’s also a critical time for brain development, which continues into a person’s twenties.

The encouraging news is that overall drug and alcohol use has declined among teens since 2009, according to the National Institute on Drug Abuse. But health experts are concerned about high rates of underage binge drinking, the sharp rise in teens using e-cigarettes and hookah pipes, and the health implications of legalizing marijuana.
Lessons learned from the ABCD study may trigger more effective preventions against teen drug and alcohol abuse, experts say, and paint a clearer picture of healthy brain development.

“Our study may yield important information on pathways whereby youth successfully navigate the stresses of adolescence,” Brown says, “and thereby offer new insights into successful coping which can inform preventions and interventions for youth.”

A More Precise Way To Study Young Brains

Advances in neuroimaging and behavioral genetics will allow researchers to explore the developing brain in great detail. At the start of the ABCD study, researchers will obtain saliva samples from the young participants to analyze genetic variation in their DNA.

“Ultimately, we hope this will help us to determine how genetic variation influences a young person’s risk for dependence, and whether treatments can be better tailored to individuals based on their genetic risks,” says Jernigan. “Stored samples will allow us to use even more powerful analyses that may be possible in the future.”

Jernigan adds that genetic risk will be studied in combination with environmental factors that can impact adolescent development. “We will examine genetic and protective factors in relation to healthy behaviors – pro-social interactions, success in school, resilience in the face of new stressors – and brain development,” she says.

Researchers will use Magnetic Resonance Imaging (MRI) to capture a picture of evolving brain structure and tissues – illuminating how the connecting fiber tracts in the brain are developing, Jernigan notes. While the youth perform game-like tasks in a scanner, images will be collected to assess the brain’s functional response and observe how connections develop between different regions of the brain.

Periodically, researchers will conduct behavioral interviews with the children and collect health data to track a variety of indicators: substance use, academic achievement, IQ, cognitive skills and mental health over time.

“We will be using technology like fit-bits, and nano-biosensors (like band aids) to measure physiological functioning and activity in ways that do not bother teens in their day-to-day activity,” Brown says.

All participation in the study is confidential, and parents who have agreed to enroll their children will not know what is being reported.

“In our past studies with teens, we have found that when we pay attention to their confidentiality concerns, they are willing to be very candid,” Brown says.

Linda Cottler, Ph.D., one of the principal investigators for the ABCD study in Florida, agrees.

“First of all, the information will be protected by a certificate of confidentiality, which means it cannot be subpoenaed. Next, the data will not be shared with the parents. With safeguards such as this, the child should be comfortable being honest,” says Cottler, Dean’s Professor and Founding Chair of the Department of Epidemiology at the University of Florida. “There will also be biological tests used to correlate with self-report,” she adds.

As one of the ABCD research sites, the University of Florida aims to follow 400 children over the next decade.

“We will use basic locating information similar to what we have done for years to achieve high rates of retention,” Cottler says. “We will elicit e-mail addresses and use novel and modern methods to reach people. We will be in touch with the family regularly over the ten years.”

Cottler says the implications of the ABCD study could be far-reaching.

“This is a landmark study,” she says, “and it will have a profound influence on the next generation of scientists too, because it will provide the means for discovery of new interventions.”