Brain Morphology at Entry into Treatment for Alcohol Dependence Is Related to Relapse Propensity

Background: We examined whether any differences in brain volumes at entry into alcohol dependence treatment differentiate subsequent Abstainers from Relapsers. Methods: Individuals in alcohol dependence treatment (n = 75) underwent magnetic resonance imaging approximately 6 +/- 4 days after their last alcoholic drink, and 40 age-matched nonsmoking light drinkers (LD) were studied as control subjects. At follow-up 7.8 +/- 2.6 months later, 23 alcoholics (31%) had abstained from drinking and 52 (69%) had relapsed. Deformation morphometry compared Relapsers, Abstainers, and LD. Results: Compared with LD, future Abstainers had smaller brain tissue volumes in the left amygdala, hippocampal head, and entorhinal cortex and bilaterally in the thalamus and adjacent subcortical white matter (WM) and had larger volume in the left lateral orbitofrontal region. Compared with LD, future Relapsers had smaller brain tissue volumes in the right middle temporal, occipital, and superior frontal WM. Compared with future Abstainers, future Relapsers had smaller tissue volumes primarily in bilateral orbitofrontal cortex and surrounding WM. Results were virtually unaffected after controlling for common comorbidities. Conclusions: At entry into alcohol dependence treatment, the brain tructure of future Relapsers differs from that of future Abstainers. Future Relapsers have smaller brain volumes in regions of the mesocorticolimbic reward system that are critically involved in impulse control, emotional regulation, craving, and evaluation and anticipation of stimulus salience and hedonics. Structural abnormalities of this circuitry might confer greater risk for resumption of hazardous drinking after treatment and might contribute to the definition of a neurobiological relapse risk profile in alcohol dependence.