The Search for Biochemical Markers

Scientists are searching for biochemical markers for alcoholism that would allow researchers to distinguish easily and reliably between alcoholics and nonalcoholics or between people at risk for alcoholism and those not at risk. Two proposed markers that have been studied intensively are the activity levels of the enzymes platelet monoamine oxidase (MAO) and platelet adenylyl cyclase (AC). Levels of MAO activity, which are genetically determined, often are significantly lower in alcoholics than in nonalcoholics. Recent studies indicate that low MAO activity levels may be a marker for a subtype of alcoholism that is characterized by an earlier age at onset. AC activity levels also are genetically determined and frequently reduced in alcoholics, compared with nonalcoholics, even after alcoholics experience long periods of abstinence. Thus, AC activity levels also may be a marker for alcoholism, although research findings indicate that low AC activity may be characteristic of a different alcoholism subtype than low MAO activity. Further studies will analyze in more detail the significance of MAO and AC activity levels as markers for alcoholism and investigate their potential role in the diagnosis, disease process, and treatment of alcoholism.