Biological markers for alcoholism: a vulnerability model conceptualization

Abstract

As the foregoing review indicates, we have made considerable progress in identifying a number of promising metabolic, behavioral, and neurophysiological markers for assessing risks for developing alcoholism. As previously noted, the term "marker" has been extended beyond its current usage in genetic marker studies where typically a blood marker has been used to elucidate the genetic transmission of particular diseases. In these studies the "ideal" marker is one which is itself an inherited characteristic that is polymorphic (there exist two or more discrete forms that are commonly found in the population), has an established mode of inheritance, is unaffected by the presence of the episode (e.g., the ABO system is unaffected by presence of a disorder), and is localizable to a particular chromosome. Few potential markers satisfy all these requirements, yet it is important to keep this in mind as we search for "markers" for vulnerability to developing alcoholism. We have proposed a vulnerability model for alcoholism in an attempt to sort out which potential markers hold promise for identifying individuals who are at risk. We have chosen to look at vulnerability from both biological and psychosocial perspectives realizing that some people may carry biological markers as part of their genetic heritage yet never develop episodes of abusive drinking because they lack psychosocial vulnerability. For example, women appear less likely to develop alcoholism than men because of cultural factors that reduce the chance that they will become heavy drinkers. The greater risk for heavy drinking among men than women appears, however, to be independent of the particular cultures. As mentioned earlier, among the 30 cultures assessed for male and female drinking practices, in no instance did women drink more than men, and in 16 men drank more than women. In the vulnerability model proposed, we assume that alcoholism is not a continuous disorder but that vulnerability, whether biological or psychosocial, is. This vulnerability may remain latent throughout life or may become manifest when triggers sufficient to produce an episode occur. These triggers may be life events or changes in the internal milieu. For example, biological changes may well produce a major affective disorder which in turn may lead to alcohol abuse. That some individuals have only one major episode of abusive drinking and never return to excessive use of alcohol attests to the fact that alcoholism should not be conceived of as a lifelong disease. Therapeutic intervention should be aimed at preventing its initial occurrence or its recurrence.(ABSTRACT TRUNCATED AT 400 WORDS)