January 06, 2026

New Study Challenges Assumptions About Addiction and Brain Changes

A widely held belief in addiction research is that brain changes observed in young people who use alcohol or drugs are primarily caused by substance use. However, a new study suggests that neuroanatomical differences in children may exist before any exposure to substances.

Led by Alex P. Miller, PhD, from Indiana University, researchers found that children with larger whole brain and cortical volumes were more likely to initiate substance use. This suggests that preexisting brain structures, environmental factors, and genetic predispositions may contribute to the risk of developing substance use disorders.

Published on December 30, 2024, in JAMA Network Open, the study analyzed data from nearly 10,000 children in the Adolescent Brain Cognitive Development (ABCD) Study. The research showed that substance use was associated with specific brain differences, including thinner cortices in some areas and thicker cortices in others. Importantly, many of these differences were present before substance use began, challenging the idea that these changes result solely from neurotoxic effects of substances.

The findings underline the importance of considering brain structure, genetics, and environment in understanding addiction and could lead to more accurate models of substance use disorders.