Alcohol Cue Reactivity and Salivary Alpha-Amylase Response in Binge Drinkers

Abstract

Alcohol Use Disorders (AUDs) are a leading cause of mortality and morbidity in the world and binge drinking is a known risk factor for the development of AUDs. Blood-level-oxygen-response (BOLD) signal during alcohol cues and cortisol, a hormone measuring the bodies hypothalamic-pituitary-adrenal stress system, have been correlated with time to relapse in individuals with AUD. But it is yet to be seen if these results are etiological factor of AUD or a result of prolonged drinking. The ventromedial prefrontal cortex (vmPFC), anterior insular cortex (AIC) and amygdala (AMYG) have been linked to cue responsivity through their roles in autonomic regulation, interoception, and craving/arousal, respectively. Furthermore, salivary alpha amylase (sAA), a digestive enzyme which correlates with sympathetic nervous system activation, an enzyme correlated with the bodies noradrenergic response to stress, has been linked with AUD. Yet, at this time a research study connecting sAA and alcohol cue reactivity has yet to be conducted. Forty-six MD (n = 20) or BD (n = 26) participants completed two functional magnetic resonance imaging (fMRI) scans during which alcohol or water cues were presented. Saliva samples were collected before and after each scan to measure sAA. We found group differences in that BD had greater levels of sAA at baseline suggesting heightened SNS arousal. We examined group differences in the vmPFC, AIC and AMYG and correlated them with sAA change scores . Group differences neural alcohol cue activity were not found, but trends between BOLD signal and sAA change across participants were. AIC BOLD signal during alcohol cues was positively correlated with sAA change, suggesting increased craving/arousal associated with SNS arousal. We found that the LAMYG and LvmPFC were both positively correlated with sAA change scores while the RAMYG and RvmPFC were negatively correlated with sAA change. Functional asymmetries such as these can be plastic or task dependent. Thus, this lateralization warrants further exploration to discover if a relationship between unilateral BOLD activity, SNS arousal and problem drinking contributes to BD