[Biological trait markers of alcohol dependence]

The early detection of individuals at high risk for the future development of alcohol dependence and the identification of trait markers for alcoholism may be useful for taking necessary measures to protect the individuals from alcoholism, for enlightening the aetiology of the illness, and even for the development of the new treatment methods. This paper reviews in detail the results of studies of trait markers in alcoholism, which have intensified particularly in recent years. Some data of the investigations indicate that a trait marker for alcoholism or a subgroup of alcohol-dependent patients may be developed: with abnormal adenylyl cyclase (AC) activity, reduced monoamine oxidase (MAO) levels, hypothalamo-pituitary-adrenal (HPA) axis abnormalities, b-endorphin abnormalities, reduced amplitude of P300 event-related potential, D2 receptor down-regulation, and decreased sensitivity to alcohol challenge as risk factors; and abnormal aldehyde dehydrogenase isoenzyme patterns as a protective factor. The review concludes that although a comprehensive trait marker for alcoholism has not yet been identified, one can hope for the identification of some consistent biological markers in a subgroup of alcohol dependents over the course of time.