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 nonetheless 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.
(JINS, 1998, 4, 319–328.)