Hippocampal Subfield Volumes in Abstinent Men and Women with a History of Alcohol Use Disorder

Alcohol use disorder (AUD) has been associated with abnormalities in hippocampal volumes, but these relationships have not been fully explored with respect to sub-regional volumes, nor in association with individual characteristics such as gender differences, age, and memory. The present study examined the impact of those variables in relation to hippocampal subfield volumes in abstinent men and women with a history of AUD. Using Magnetic Resonance Imaging at 3 Tesla, we obtained brain images from 67 participants (31 women) with AUD and 63 healthy control (NC) participants (30 women) without AUD. We used Freesurfer 6.0 to segment the hippocampus into 12 regions. These were imputed into mixed models to examine the relationships of brain volume with AUD group, gender, age, drinking history, and memory. The AUD group had approximately 5% smaller CA1, hippocampal tail, and molecular layer regions than the NC group. Age was negatively associated with volumes for the AUD group in the hippocampal tail, subiculum, and presubiculum. The relationships for delayed and immediate memory with hippocampal tail volume differed for AUD and NC groups: Higher scores were associated with smaller volumes in the AUD group, but larger volumes in the NC group. Length of sobriety was associated with decreasing CA1 volume in women (0.02% per year) and increasing volume size in men (0.03% per year). These findings confirm and extend evidence that AUD, gender, age, and abstinence differentially impact volumes of component parts of the hippocampus. The course of abstinence on CA1 volume differed for men and women, and the differential relationships of subregional volumes to age and memory could indicate a distinction in the impact of AUD on functions of the hippocampal tail.