Preliminary evidence of reduced cognitive inhibition in methamphetamine-dependent individuals.
Chronic methamphetamine abuse is associated with disruption of frontostriatal function involving serotonin and dopamine circuitry. Clinically, methamphetamine-dependent (MD) individuals are highly distractible and have difficulty focussing. Here, we used a computerized single-trial version of the Stroop Test to examine selective attention and priming in MD. Subject groups comprised eight MD men (31.7+/-7.2 years of age), who had used methamphetamine for 15.75+/-8.4 years but were currently abstinent for 2-4 months, and 12 controls (35.7+9.7 years of age). Compared with the control group, the MD group exhibited significantly greater interference (P<0.05) despite intact priming. Error rates did not differ between the groups. This preliminary finding of reduced cognitive inhibition in MD individuals is consistent with the distractibility they show clinically. Furthermore, the dissociation between explicit attentional performance and priming effects suggests that some attentional functions are not as affected by long-term methamphetamine use as others.
Department of Psychiatry, UC Davis Medical Center, 2230 Stockton Blvd, Sacramento, CA 95817, USA. resalo@ucdavis.edu
Ruth
R
Salo
Thomas E
TE
Nordahl
Kate
K
Possin
Martin
M
Leamon
David R
DR
Gibson
Gantt P
GP
Galloway
Neil M
NM
Flynn
Avishai
A
Henik
Adolf
A
Pfefferbaum
Edith V
EV
Sullivan
D000328:Adult; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D003342:Corpus Striatum / Q000503:physiopathology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D008297:Male; D008694:Methamphetamine; D009483:Neuropsychological Tests; D010259:Paranoid Disorders / Q000209:etiology / Q000503:physiopathology; D011930:Reaction Time; D012720:Severity of Illness Index; D019966:Substance-Related Disorders / Q000150:complications*; D011795:Surveys and Questionnaires
D008694:Methamphetamine