Associations Between Recent Heavy Drinking and Dorsal Anterior Cingulate N-Acetylaspartate and Glutamate Concentrations in Non-Treatment-Seeking Individuals with Alcohol Dependence

BackgroundProton magnetic resonance spectroscopy (H-1-MRS) studies have consistently found abnormal brain concentrations of N-acetylaspartate (NAA) and glutamate in individuals with alcohol use disorders (AUD) relative to light drinkers. However, most such studies have focused on individuals in treatment for severe alcohol dependence (AD), and few studies have investigated associations between neurochemical concentrations and recent alcohol consumption. This study focused on associations between recent drinking and prefrontal neurometabolite concentrations in nonsevere, non-treatment-seeking individuals with AUD. MethodsNineteen treatment-naive alcohol-dependent individuals aged 21 to 40 completed a H-1-MRS scan. Single-voxel H-1-MRS spectra were acquired in dorsal anterior cingulate cortex (dACC) using a 2-dimensional J-resolved point resolved spectroscopy sequence. Associations between recent heavy drinking, assessed using the Timeline FollowBack, and dACC metabolite concentrations were estimated via regression controlling for within-voxel tissue composition. ResultsParticipants provided a negative breathalyzer reading and reported between 1 and 5days (M=2.45, SD=1.23) since their last drink. Number of heavy drinking days in the 14days preceding the scan (M=4.84, SD=3.32) was significantly inversely associated with both glutamate/water (=-0.63, t(17)=-3.37, p=0.004) and NAA/water concentrations (=-0.59, t(17)=-2.98, p=0.008). ConclusionsThis study extends the literature by demonstrating inverse associations between recent heavy drinking and dACC glutamate and NAA concentrations in a sample of nonsevere, non-treatment-seeking individuals with AD. These findings may support the hypothesis that amount of recent alcohol consumption may account for differences in neuronal metabolism, even in nonsevere, non-treatment-seeking alcoholics.