Researchers have identified distinct brain structure differences of those who used substances before age 15. The study, funded by the National Institutes of Health (NIH), followed nearly 10,000 adolescents for three years. Researchers found that many of the differences existed in childhood, even before substance use began—highlighting a potential predisposition to substance abuse.
“This adds to some emerging evidence that an individual’s brain structure, alongside their unique genetics, environmental exposures, and interactions among these factors, may impact their level of risk and resilience for substance use and addiction,” said Nora Volkow M.D., director of NIDA, in a press release.
The study identified both brain-wide and regional structural differences, particularly in the cortex. Some affected areas have been linked to sensation-seeking and impulsivity, but researchers caution that more work is needed to determine how these differences translate to brain function and behavior. They also stress the role of genetics, environment, and prenatal influences in shaping these outcomes.
“Understanding the complex interplay between the factors that contribute and that protect against drug use is crucial for informing effective prevention interventions and providing support for those who may be most vulnerable,” said Volkow.
Among the 3,460 adolescents who reported substance use before age 15, alcohol was the most common (90.2%), often overlapping with nicotine (61.5%) and cannabis (52.4%) use.
While the findings could help shape clinical prevention efforts, researchers note that brain structure alone cannot predict substance use and should not be used as a diagnostic tool.