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Cognitive Efficiency in Stimulant Abusers With and Without Alcohol Dependence
Author(s) -
LawtonCraddock Andrea,
Nixon Sara Jo,
Tivis Rick
Publication year - 2003
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1097/01.alc.0000056620.98842.e6
Subject(s) - stimulant , cognitive flexibility , cognition , psychology , substance abuse , neuropsychology , effects of sleep deprivation on cognitive performance , clinical psychology , alcohol abuse , audiology , psychiatry , developmental psychology , medicine
Background: Although previous studies have found stimulant (i.e., cocaine, methamphetamine) abusers and alcoholics to have neuropsychological deficits, research examining which cognitive abilities are most affected by concurrent exposure to these substances is lacking. To address this issue, detoxified men and women who met criteria for dependence of (a) alcohol only (ALC) ( n = 15); (b) stimulants only (STIM) ( n = 15); and (c) both alcohol and stimulants (A/STIM) ( n = 15) were compared with age‐ and education‐matched community controls ( n = 15). Methods: Tasks that measured visual spatial skills, problem‐solving and abstraction, short‐term memory, cognitive flexibility, and gross motor speed were administered to participants. For each test, both speed and accuracy were assessed and an efficiency ratio (accuracy/time) was derived. Based on an average of these efficiency ratios, an overall performance index of cognitive efficiency was obtained. Results: Overall, controls performed more efficiently than all other groups. However, they were statistically significantly better only in relation to the A/STIM and STIM groups ( p < 0.01). Individual comparisons revealed that the ALC group performed significantly better than the STIM group, although the ALC group did not differ from either the control or A/STIM groups ( p ≤ 0.05). This pattern of results was relatively consistent across the individual subtests of problem‐solving/abstraction, short‐term memory, and cognitive flexibility. Conclusions: As expected, substance abuse was associated with cognitive inefficiency. More importantly, these findings suggest that the cognitive effects of chronic stimulant abuse are not additive with those of alcohol abuse. That is, singly addicted stimulant abusers demonstrated similar or greater neurocognitive impairments than individuals who abuse alcohol and stimulants concurrently. The reason for this pattern is speculative but may be attributed to alcohol's opposing actions on cerebrovascular effects brought on by stimulant abuse.