SUBTYPES OF ALCOHOL-DEPENDENT MEN - A TYPOLOGY BASED ON RELATIVE GENETIC AND ENVIRONMENTAL LOADING

Using scales that distinguish between relative genetic and environment al loading, cluster analysis was used to identify three subtypes of al cohol dependence in Caucasian men from the Epidemiologic Catchment Are a study (n = 911). Although all subjects met DSM-III criteria for alco hol dependence, only the severe subtype showed evidence of substantial genetic influence, When compared on a range of clinical characteristi cs, the mild subtype (53% of the sample) was typically least adversely affected and the severe subtype (17%) most affected, with the dyssoci al subtype (30%) falling between. Severe subtype subjects had signific antly greater comorbid drug dependence and were at least four times mo re likely than mild subjects to have sought treatment for alcohol prob lems, Ratio of genetic scale score to total symptom count (genetic rat io) was highest for the severe subtype (mean = 0.37), and negatively c orrelated with age of first alcohol problem (r(s) = -0.16) and years b etween first intoxication and first problem (r(s) = -0.19). No signifi cant correlations were found between these clinical features and genet ic ratio for the mild or dyssocial subtypes. Use of these scales and s ubtypes may improve our ability to detect specific gene effects in gen etic linkage studies and to identify environmental influences in behav ioral and epidemiological studies.