Early onset adolescent binge drinking is associated with reduced white matter integrity in post-9/11 adult veterans.

Adolescence represents a critical period of neural development during which binge drinking (BD) is prevalent. Though prior work has shown that white matter (WM) integrity is susceptible to damage from excessive alcohol intake in adults, the effect of early adolescent BD on WM health in adulthood remains unknown. Veterans with a history of BD onset before age 15 [n = 49; mean age = 31.8 years; early-onset adolescent binge drinkers (EBD)] and after age 15 [n = 290; mean age = 32.2 years; late-onset adolescent binge drinkers (LBD)] were studied with diffusion tensor imaging. Group differences in fractional anisotropy (FA; movement of water molecules along the WM) and mean diffusivity (MD; average movement of water molecules) were examined as indices of WM integrity using FreeSurfer and FMRIB Software Library (FSL) processing streams. Lower FA and higher MD are thought to represent degradations in WM integrity. A reference group (RG) of social drinkers with no history of BD (n = 31) was used to provide comparative normative data. We observed widespread decreased FA and increased MD in EBDs, compared to LBDs, as well as decreased FA in the pars triangularis, lateral orbitofrontal cortex, superior frontal cortex, isthmus cingulate, and genu and splenium of the corpus callosum EBDs also had lower WM integrity compared to the RG. Adults who initiated BD during early adolescence demonstrated decreased FA and increased MD throughout the frontostriatal circuits that mediate inhibitory control and thus may result in impulsive behavior and a predisposition for developing alcohol use disorder during adulthood.

Age of onset of adolescent binge drinking is differentially associated with cortical thickness in post-9/11 adult Veterans.

BACKGROUND: Adolescence is a critical period for neural development and has been associated with high rates of alcohol abuse. This research examined potential long-term brain and behavioral effects of early versus late-onset adolescent binge drinking in an adult sample of post-9/11 Veterans. METHODS: We compared cortical thickness measures in Veterans with a history of binge drinking that began before the age of 15 (n = 50; mean age = 32.1 years) to those with a history of binge drinking with onset after the age of 15 (n = 300; mean age = 32.1 years). Data processing was conducted with FreeSurfer. A targeted neuropsychological battery (Digit Span test, Delis-Kaplan Executive Function System Color-Word Interference Test, California Verbal Learning Test-II) was used to examine the relationships between cortical thickness and attention, memory, and inhibition. A reference group of social drinkers with no history of early binge drinking (n = 31) was used to provide normative data. RESULTS: Early-onset adolescent binge drinkers (EBD) had greater cortical thickness in several regions than late-onset adolescent binge drinkers (LBD); both binge-drinking groups had greater cortical thickness than the reference group. There was a stronger negative association between cortical thickness and age in EBDs than LBDs in the (i) lateral orbitofrontal cortex, (ii) supramarginal gyrus, (iii) paracentral lobule, and (iv) anterior caudal cingulate. Poorer performance on the attention and inhibition tasks in the EBDs was also associated with thicker cortices. CONCLUSIONS: This study demonstrates greater cortical thickness across frontoparietal regions in adults who began binge drinking in early versus late adolescence. A stronger negative association between cortical thickness and age in the EBDs suggests that early-onset adolescent binge drinking may be associated with accelerated cortical thinning. Thicker cortex in these regions, which are known to mediate inhibitory control, may increase impulsive behavior and contribute to the risk of alcohol addiction.