Cognitive enhancing effects of modafinil in healthy volunteers.
BACKGROUND
Modafinil, a novel wake-promoting agent, has been shown to have a similar clinical profile to that of conventional stimulants such as methylphenidate. We were therefore interested in assessing whether modafinil, with its unique pharmacological mode of action, might offer similar potential as a cognitive enhancer, without the side effects commonly experienced with amphetamine-like drugs.


OBJECTIVE
The main aim of this study was to evaluate the cognitive enhancing potential of this novel agent using a comprehensive battery of neuropsychological tests.


METHODS
Sixty healthy young adult male volunteers received either a single oral dose of placebo, or 100 mg or 200 mg modafinil prior to performing a variety of tasks designed to test memory and attention. A randomised double-blind, between-subjects design was used.


RESULTS
Modafinil significantly enhanced performance on tests of digit span, visual pattern recognition memory, spatial planning and stop-signal reaction time. These performance improvements were complemented by a slowing in latency on three tests: delayed matching to sample, a decision-making task and the spatial planning task. Subjects reported feeling more alert, attentive and energetic on drug. The effects were not clearly dose dependent, except for those seen with the stop-signal paradigm. In contrast to previous findings with methylphenidate, there were no significant effects of drug on spatial memory span, spatial working memory, rapid visual information processing or attentional set-shifting. Additionally, no effects on paired associates learning were identified.


CONCLUSIONS
These data indicate that modafinil selectively improves neuropsychological task performance. This improvement may be attributable to an enhanced ability to inhibit pre-potent responses. This effect appears to reduce impulsive responding, suggesting that modafinil may be of benefit in the treatment of attention deficit hyperactivity disorder.
Turner
Danielle C
DC
Department of Psychiatry, University of Cambridge, School of Clinical Medicine, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK.
Robbins
Trevor W
TW
Clark
Luke
L
Aron
Adam R
AR
Dowson
Jonathan
J
Sahakian
Barbara J
BJ
D000328:Adult; D001559:Benzhydryl Compounds / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D003071:Cognition / Q000187:drug effects*; D003657:Decision Making / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects; D000077408:Modafinil; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010147:Pain Measurement; D010364:Pattern Recognition, Visual / Q000187:drug effects; D011581:Psychological Tests
D001559:Benzhydryl Compounds; D018696:Neuroprotective Agents; D000077408:Modafinil