Background: Alcoholics report persistent alcohol craving that is heightened by cognitive cues, stressful situations, and abstinence. The role of endogenous cannabinoids in human alcohol craving--though long suspected--remains elusive.
Materials and methods: We employed laboratory exposure to stress, alcohol cue, and neutral relaxed situations through guided imagery procedures to evoke alcohol desire and craving in healthy social drinkers (n = 11) and in treatment-engaged, recently abstinent alcoholic subjects (n = 12) and assessed alcohol craving, heart rate, and changes in circulating endocannabinoid levels. Subjective anxiety was also measured as a manipulation check for the procedures.
Results: In healthy social drinkers, alcohol cue imagery increased circulating levels of the endocannabinoid anandamide, whereas neutral and stress-related imagery had no such effect. Notably, baseline and response anandamide levels in these subjects were negatively and positively correlated with self-reported alcohol craving scores, respectively. Cue-induced increases in heart rate were also correlated with anandamide responses. By contrast, no imagery-induced anandamide mobilization was observed in alcoholics, whose baseline anandamide levels were markedly reduced compared to healthy drinkers and were uncorrelated to either alcohol craving or heart rate.
Conclusions: The results suggest that plasma anandamide levels provide a marker of the desire for alcohol in social drinkers, which is suppressed in recently abstinent alcoholics.