Methylphenidate enhances prepulse inhibition during processing of task-relevant stimuli in attention-deficit/hyperactivity disorder.
ADHD is characterized by inattention, hyperactivity, and disinhibition, including the inability to screen out distracting stimuli. Prepulse inhibition (PPI) of startle indexes a related gating process and is enhanced during attended compared to ignored stimuli. We predicted that PPI during attended stimuli would be enhanced by the stimulant methylphenidate (MPH) and that this effect would be moderated by baseline PPI. Children with ADHD (n=36) completed a baseline day and a randomized, double-blind medication trial (placebo vs. sustained release MPH). Bilateral startle eyeblink EMG was measured during a tone discrimination task. MPH enhanced PPI during attended, but not during ignored stimuli. Extending findings that pretreatment functioning moderates stimulant effects on PPI, this effect tended to be inversely related to baseline PPI. These data fit with the clinical literature on ADHD and the hypothesis that MPH enhances interference control for important environmental stimuli.
Department of Psychology, University at Buffalo, SUNY, Buffalo, New York 14260-4110, USA.
Rebecca L
RL
Ashare
Larry W
LW
Hawk
Keri
K
Shiels
Jessica D
JD
Rhodes
William E
WE
Pelham
James G
JG
Waxmonsky
D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000523:psychology*; D001767:Blinking / Q000502:physiology; D000697:Central Nervous System Stimulants / Q000494:pharmacology* / Q000627:therapeutic use; D002648:Child; D003627:Data Interpretation, Statistical; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology* / Q000627:therapeutic use; D011597:Psychomotor Performance / Q000502:physiology*; D013216:Reflex, Startle / Q000187:drug effects*
D000697:Central Nervous System Stimulants; D008774:Methylphenidate