Abstract
IMPORTANCE: The effects of prenatal alcohol (PAE) and tobacco exposure (PTE) on adolescent neuroanatomical development are typically evaluated cross-sectionally. It is unclear if observed effects persist throughout life or reflect different developmental trajectories. OBJECTIVE: To determine how PAE and PTE are associated with cortical structure and development across two timepoints in early adolescence. DESIGN: Observational, longitudinal analyses of data within the Adolescent Brain Cognitive Development Study. SETTING: 21 study sites in the United States. PARTICIPANTS: 5,417 youth participants, aged ~9-12 years old. EXPOSURES: PAE and PTE based on caregiver (self) reports of alcohol/tobacco use during pregnancy, before and after pregnancy recognition. MAIN OUTCOMES AND MEASURES: Cortical thickness (mm) and cortical surface area (mm(2)) measured approximately 2 years apart in early adolescence, across 68 bilateral cortical regions. RESULTS: At baseline data collection, youth participants were ~9.9 years old (SD=0.6). At the second neuroimaging appointment, youth participants were ~11.9 years old (SD=0.6). When modelling cortical thickness, we controlled for individuals' whole-brain volume; when modelling cortical surface area, individuals' total surface area. Cortical thickness generally declined with age. Cortical surface area either expanded or contracted with age, depending on region. PAE had minimal effects on cortical structure (main effects) and development (PAE×Age interactions). PTE had robust effects on cortical thickness and was associated with faster rates of cortical thinning in several regions within the frontal lobe. Post hoc analyses on (1) the effects of PTE for those who continued tobacco use after pregnancy recognition and (2) the effects of PTE in those who did not also use alcohol revealed weaker effects. CONCLUSIONS AND RELEVANCE: PTE had robust effects on neuroanatomical structure and longitudinal development, particularly cortical thickness. Analyzing developmental cortical trajectories informs how PTE and/or PAE not only affects cortical structure but how it develops long after those prenatal exposures occurred. Future analyses involving cotinine biomarkers of PTE would enhance the temporal resolution of the ABCD Study(®)'s PTE-related queries of tobacco use before and after learning of the pregnancy.