Modafinil improves cognition and response inhibition in adult attention-deficit/hyperactivity disorder.
BACKGROUND
Modafinil, a novel cognitive enhancer, has a clinical profile similar to conventional stimulants such as methylphenidate, despite a seemingly different mechanism of action. Modafinil selectively improves neuropsychological task performance in healthy volunteers, possibly through improved inhibitory control. We examined whether modafinil induced similar improvements in adults with attention-deficit/hyperactivity disorder.


METHODS
Twenty patients with a DSM-IV diagnosis of attention-deficit/hyperactivity disorder were entered into a double-blind, randomized, placebo-controlled crossover study using a single 200 mg dose of modafinil.


RESULTS
Modafinil produced a similar pattern of cognitive enhancement to that observed in healthy adults, with improvements on tests of short-term memory span, visual memory, spatial planning, and stop-signal motor inhibition. On several measures, increased accuracy was accompanied by slowed response latency. This alteration in the speed-accuracy trade-off may indicate that modafinil increases the ability to "reflect" on problems coupled with decreased impulsive responding. Improvements were also seen in sustained attention, which was unaffected in healthy subjects.


CONCLUSIONS
If these benefits are shown to be maintained with chronic administration, modafinil may have potential as an important therapy for attention-deficit/hyperactivity disorder with a similar effect to stimulants such as methylphenidate in improving stop-signal response inhibition but without the side effects commonly experienced with amphetamine-like drugs.
Turner
Danielle C
DC
Department of Psychiatry, University of Cambridge, School of Clinical Medicine, Cambridge, United Kingdom.
Clark
Luke
L
Dowson
Jonathan
J
Robbins
Trevor W
TW
Sahakian
Barbara J
BJ
D000328:Adult; D001288:Attention / Q000187:drug effects; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy*; D001559:Benzhydryl Compounds / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D003071:Cognition / Q000187:drug effects; D018592:Cross-Over Studies; D003657:Decision Making / Q000187:drug effects; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007266:Inhibition, Psychological; D007360:Intelligence / Q000187:drug effects; D007361:Intelligence Tests; D008297:Male; D008568:Memory / Q000187:drug effects; D000077408:Modafinil; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010147:Pain Measurement; D011581:Psychological Tests / Q000706:statistics & numerical data; D011597:Psychomotor Performance / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects
D001559:Benzhydryl Compounds; D000697:Central Nervous System Stimulants; D000077408:Modafinil