Verbal learning and memory in alcohol abusers and polysubstance abusers with concurrent alcohol abuse.

To define the combined effects of drug and alcohol abuse on verbal learning and memory, 70 alcoholic and 80 polysubstance abuse (PSA) individuals with concurrent alcohol abuse were compared on a list learning task, the California Verbal Learning Test (CVLT). Despite demonstrating similar learning strategies, response styles, and error patterns, the PSA group nontheless exhibited significantly greater recall deficits than the alcoholic group on the CVLT. These deficits were particularly evident in those who were heaviest abusers of cocaine. PSA participants did not, however, evidence greater recognition memory deficits. This pattern of greater deficits on recall than on recognition memory, as well as poor consolidation, is consistent with the initiation-retrieval difficulties of patient groups with subcortical dysfunction. It is concluded that the combined use of alcohol and drugs, cocaine in particular, may compound memory difficulties beyond what is typically observed in alcoholic individuals.