Acute effects of cocaine in two models of inhibitory control: implications of non-linear dose effects.
OBJECTIVE
This study examined dose-response effects of oral cocaine on the inhibitory control of behavior in adult cocaine users using two different behavioral models of inhibitory control.


METHODS
Adults (n = 12) with a history of cocaine use performed the stop-signal and cue-dependent go-no-go task to measure inhibitory control of behavior in response to a range of oral cocaine HCl doses (0, 100, 200 and 300 mg).


RESULTS
Although both tasks showed cocaine-induced facilitation of inhibitory control, dose-response functions differed depending on the measures. The stop-signal measure revealed a quadratic dose-response function and the cued go-no-go measure showed a more orderly, linear improvement as a function of dose.


CONCLUSIONS
The evidence suggests a two-phasic dose-response in which facilitating effects of stimulant drugs on inhibitory control might be limited to a range of intermediate doses, above which improvement is no longer evident and impairing effects could possibly emerge.
Fillmore
Mark T
MT
Department of Psychology, University of Kentucky, Lexington, KY 40506-0044, USA. fillmore@uky.edu
Rush
Craig R
CR
Hays
Lon
L
D000328:Adult; D003042:Cocaine / Q000009:adverse effects*; D019970:Cocaine-Related Disorders / Q000523:psychology*; D003463:Cues; D018765:Dopamine Uptake Inhibitors / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged
D018765:Dopamine Uptake Inhibitors; D003042:Cocaine