PATTERNS OF COGNITIVE IMPAIRMENT AMONG ALCOHOLICS - ARE THERE SUBTYPES

The mild generalized dysfunction hypothesis of alcohol abuse's deleter ious effects on cognitive processes has gained support from a number o f studies in which detoxified alcoholics have a lower mean performance level than peer controls on a variety of neuropsychological tests. Th is approach might obscure consistent but different patterns of preserv ed and impaired cognitive performance among subgroups of alcoholics, s uggestive Of alternative hypotheses. To test this possibility, neurops ychological test data from two large, independent samples of alcoholic s (sample 1, n = 143; sample 2, n = 130) and controls (sample 1, n = 9 7; sample 2, n = 83) were subjected to separate centroid hierarchical cluster analyses. For both samples, the majority of alcoholics (94% an d 94%) exhibited a pattern of impaired verbal and nonverbal performanc e and deficits in memory and perceptual motor skill, with normal motor skill. The alcoholics who did not fit this pattern showed more severe or wide-ranging impairments. These findings indicate that empirical s upport for the mild generalized dysfunction hypothesis of alcoholics' cognitive deficits is not an artifact of averaging.