Abstract
The extent to which neuroanatomical variability associated with substance involvement reflects pre-existing risk and/or consequences of substance exposure remains poorly understood. In the Adolescent Brain Cognitive Development(SM) (ABCD(®)) Study, we identify associations between global and regional differences in brain structure and early substance use initiation (i.e., occurring <15 years of age; ns(analytic)=6,556-9,804), with evidence that associations precede initiation. Neurodevelopmental variability in brain structure may confer risk for substance involvement.