Subjective response to alcohol in typically developing emerging adults and those with bipolar disorder, associated alcohol use, and orbitofrontal gray matter volume

Abstract

Co-occurring alcohol use disorders (AUDs) are highly prevalent in bipolar disorder, though the developmental etiology of this comorbidity remains unknown. A decreased subjective response (SR) to alcohol and differential structure and function of the orbitofrontal cortex (OFC) have been implicated in problematic alcohol consumption in typically developing populations. Differential structure of the OFC has been linked to alcohol use problems in bipolar disorder, yet the underlying mechanisms of this relation are unknown. In this preliminary investigation, SR to alcohol, recent alcohol use, and variation in OFC gray matter volume (GMV)—and associations among these factors—were investigated in 48 emerging adults (24 typically developing, mean age=21, 67% female; 24 bipolar disorder, mean age=21, 75% female). Clinical, behavioral, and structural magnetic resonance imaging data was collected, including Self-Rating of the Effects of Alcohol scale, recent alcohol use, and drinking motives. No significant between-group differences in SR or alcohol use were observed, but a decreased SR to alcohol was associated with greater recent alcohol consumption in both groups (p<.05). Decreased SR to alcohol was associated with lower GMV in OFC in typically developing emerging adults, and greater GMV in OFC in those with bipolar disorder (group by SR interaction p<.001, uncorrected). In both groups, variation in OFC GMV was also differentially related to drinking motives (p<.05). Findings suggest a transdiagnostic association between SR to alcohol and increased alcohol consumption, with differences in OFC structure contributing to this relation. Longitudinal studies are needed to examine how these associations relate to risk/development of AUDs