Frontal Brain N-Acetylaspartate at Treatment Entry is Related to Future WHO Risk Drinking Levels in Individuals with Alcohol Use Disorder.

Objective: To assess the viability of regional brain metabolite levels of individuals with alcohol use disorder (AUD) at treatment entry as a biomarker of post-treatment levels of alcohol use, categorized according to the World Health Organization risk drinking levels (WHO-RDL).

Method: Eighty-five individuals initiating treatment for AUD (16 ± 13 days after last alcohol consumption), and 45 light/non-drinking controls (LN) completed a 1.5T proton multislice magnetic resonance spectroscopic imaging study. N-acetylaspartate (NAA), a marker of neuronal viability, and other metabolites were quantitated for cortical gray matter (GM), white matter (WM) and select subcortical regions. Individuals with AUD were classified according to their post-treatment alcohol consumption, as abstainers (AB, n=42), low risk (RL, n=20), or higher risk (RH, n=23), based on the WHO-RDL taxonomy.

Results: Within frontal GM, RH exhibited significantly lower NAA levels than LN and AB but did not differ from RL. RH had significantly lower NAA concentration in frontal WM than all groups who did not significantly differ from one another. RH showed significantly lower parietal WM NAA than LN and AB; RL and RH did not differ from one another. Across RH and RL, lower frontal GM and WM NAA was related to shorter period of abstinence before first post-treatment alcohol consumption and longer post-treatment duration of alcohol resumption. There were no significant group differences in myo-inositol or choline- or creatine-containing compound concentrations.

Conclusions: Frontal and parietal lobar NAA concentrations, near treatment entry, are associated with WHO-RDL categorized post-treatment alcohol consumption levels and may serve as predictive biomarkers of clinical outcomes following treatment for AUD.