A test of alcohol dose effects on multiple behavioral measures of impulsivity.
BACKGROUND
Acute alcohol administration affects impulsive behavior, although these effects vary as a function of alcohol dose, assessment instrument, and time of measurement following administration.


METHODS
We concurrently examined the dose-dependent effects of alcohol on three distinct types of impulsivity tasks (continuous performance [IMT], stop-signal [GoStop], and delay-discounting [SKIP] tasks). Ninety healthy alcohol drinkers were assigned to one of the three task groups (n=30 each), each group experienced placebo, 0.2, 0.4, 0.6, and 0.8 g/kg alcohol doses across 5 experimental days, and task performance was assessed at 0.5h before and 0.25, 1.0, and 2.0 h after alcohol administration. We hypothesized that impulsive responding on all tasks would be increased by acute alcohol administration both across time and during the peak BrAC, but the magnitude would depend on the task being tested. Analyses included the time course and the peak BrAC effects. Task comparisons of peak behavioral changes following each dose are illustrated using standardized scores.


RESULTS
While alcohol consumption increased impulsive responding during all three tasks to some extent, our hypothesis was only partially supported. During the IMT, the 0.6 and 0.8 g/kg doses produced increased impulsive responding across time and at the peak BrAC. However, during the GoStop and SKIP, impulsivity increased across time regardless of the alcohol dose size, with no differences in impulsive responding among dose conditions at peak BrAC.


CONCLUSIONS
This study demonstrated alcohol-induced changes in impulsivity are not uniformly affected by alcohol. These data, in conjunction with previous studies, further support that impulsivity is not a unitary construct.
Dougherty
Donald M
DM
Neurobehavioral Research Laboratory and Clinic, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA. doughertyd@uthscsa.edu <doughertyd@uthscsa.edu>
Marsh-Richard
Dawn M
DM
Hatzis
Erin S
ES
Nouvion
Sylvain O
SO
Mathias
Charles W
CW
D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects / Q000097:blood / Q000523:psychology*; D000434:Alcoholic Beverages / Q000706:statistics & numerical data; D001944:Breath Tests / Q000379:methods; D002492:Central Nervous System Depressants / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000009:adverse effects* / Q000032:analysis / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000097:blood / Q000139:chemically induced* / Q000523:psychology*; D008297:Male; D008568:Memory / Q000187:drug effects; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010919:Placebos; D011597:Psychomotor Performance / Q000187:drug effects; D013647:Task Performance and Analysis; D013997:Time Factors
D002492:Central Nervous System Depressants; D010919:Placebos; D000431:Ethanol