When studying substance use disorders, scientists had thought some of the effects on the brain could stem from use of the substances themselves: People start drinking alcohol in early teens, that alcohol has a neurotoxic effect on the developing brain that begets more alcohol drinking, and a similar dynamic occurs with other substances.
But research from Washington University in St. Louis turns that thinking around. Certain features of brain structure may be one of the factors that can contribute to substance use initiation.
WashU researchers in Art & Sciences and the School of Medicine studied the brain scans of nearly 10,000 children in the large-scale Adolescent Brain Cognitive Development Study. The idea was to compare results of scans between participants who did and did not go on to start trying substances in early teens. What they found were correlations between certain types of brain structure and those that do try substances before age 15.
“What we looked at was whether these neural differences precede any substance involvement essentially. And we do find that,” said Ryan Bogdan, PhD, the Dean’s Distinguished Professor of Psychological & Brain Sciences in Arts & Sciences and co-author of this research, published Dec. 30 in JAMA Network Open.
In the research, Bogdan, along with first author Alex Miller, at Indiana University School of Medicine, and Arpana Agrawal, PhD, the James and Juanita Wittmer Professor in the Department of Psychiatry at WashU Medicine, highlighted a number of structural differences in the cortex, including the prefrontal cortex, that may contribute to trying substances in adolescence.
Researchers emphasized this is just one piece of a puzzle in the progression of substance use; other pieces include the genetic building blocks that factor into brain structure from the get-go and early home environments.