Tracking the developing brain from childhood to adulthood

By Vanessa Vinson

Each year, participants and a parent visit U-M to complete extensive assessments examining mental health, cognition, sleep, physical health, family relationships and environmental influences. Every other year, researchers also collect brain imaging data to better understand how brain structure and function change throughout adolescence.

“Our goal with the ABCD Study is to determine how youth experiences interact with changing biology to affect brain development and social, behavioral, academic and health outcomes,” said Mary Heitzeg, U-M professor of psychiatry and lead ABCD investigator.

The study was originally conceived to better understand how substance use affects the developing adolescent brain. Researchers recognized that adolescence is often accompanied by increased risk-taking behaviors, including experimentation with alcohol, marijuana and nicotine. To understand how substance use might influence brain development and future outcomes, scientists needed to begin collecting data before substance use typically begins, which led researchers to recruit children at ages 9 and 10.

“It became clear that the information we collect could provide the opportunity to answer much broader questions regarding brain development and outcomes,” Heitzeg said.

That expanded vision helped transform ABCD into what many researchers now consider a landmark project in child brain development research.

Before ABCD, many neuroscience studies relied on relatively small participant groups and narrowly focused datasets. The ABCD Study instead adopted a large-scale “team science” model that brought together researchers from multiple disciplines and institutions to create a more comprehensive understanding of adolescent development.

“What we now know is that these studies are often too small, too noisy and too fragmented to assemble into a coherent picture,” said Chandra Sripada, U-M professor of psychiatry and co-lead investigator on the study. “To make progress, scientists had to stop the old way and start teaming up.”

The study has also identified important associations between socioeconomic environments and brain development. Researchers found that household socioeconomic resources are associated with significant differences in children’s brain connectivity patterns, even after accounting for numerous other factors.

For researchers, one of the study’s most significant contributions may be its ability to help shift mental health care toward earlier intervention and prevention.

“Mental health care for youth is largely reactive,” Sripada said. “We wait until a youth encounters problems, and then we initiate treatment and follow-up.”

By following participants over many years, researchers can begin identifying early biological, environmental and behavioral signals that may predict future mental health challenges or substance use disorders. Researchers can also better understand which protective factors support resilience among youth facing increased risk.

Now that many participants are entering adulthood, researchers say the study is reaching a particularly important stage.

“This next phase is when many important life patterns become clearly established and solidified,” Sripada said. “The early phase of ABCD told us what matters. The next phase will tell us when it matters, for whom it matters and which early signals truly predict later outcomes.”

For researchers involved in the project, the long-term potential to improve youth well-being continues to drive the work forward.

“I believe this is exactly the kind of science needed to truly make a difference when it comes to helping children grow into successful, healthy adults,” Heitzeg said. “It brings together expertise from neuroscience, psychology, psychiatry, medicine and education to conduct groundbreaking research that can ultimately influence wellbeing on a broad scale.”