AUDs may transmit from one generation to other and have a high degree of familial association[5]. Many twin, adoption and family studies have provided consistent evidence for genetic predispositions to AUDs[6–8]. Heritable influences account for approximately 40% to 60% of the total variance to risk for alcoholism[6, 7]. A host of other social, cultural and personal factors also influence the drinking behaviors of an individual[9]. It is also important to remember that availability of alcohol is the most important factor that influences the outcome of AUD[1, 10]. A person who has never tried alcohol can not become alcohol dependent in spite of his/ her genetic susceptibility to alcoholism. Therefore it is pretty safe to assume that AUD results from a complex interplay of genetic susceptibility (genes associated with risk), environmental influences, and history of alcohol exposure[11, 12]. These combined factors likely contribute to system-wide epigenetic alterations, post-translational modifications, and long-term allostatic changes in brain regions that underlie the alcohol use disorder[12].
