Stimulant drug effects on attention deficit/hyperactivity disorder: a review of the effects of age and sex of patients.
OBJECTIVE
As dopamine functioning varies by sex and age it might be expected that the effects of methylphenidate or amfetamine, the psychostimulants used for the treatment of Attention Deficit /Hyperactivity Disorder (ADHD), will also be moderated by these factors. Here we review the published literature on whether stimulant effects in ADHD symptoms vary by age and sex.


METHODS
We searched for studies published from 1989 until October 2009. Databases searched included U.S. National Library of Medicine (PubMed), Medline, EMBASE, PsycINFO and ISI Web of Knowledge. Firstly, we reviewed the effects of stimulant drugs on male and female patients and also patients of pre-school, middle childhood, adolescence and adulthood. Secondly, we reviewed studies that directly tested the moderating effect of age and sex on stimulant treatment outcome.


RESULTS
Randomised controlled trials confirm that stimulant medication is efficacious for, and well tolerated by, males and females and patients across the age range; although preschoolers appear to have a less beneficial response and more side effects. Few studies that specifically examined the moderating effect of age and/or sex were identified. For sex, no effects on overall response were found, although one study reported that sex moderated methylphenidate pharmacodynamics. The few effects found for age were small and inconsistent.


CONCLUSIONS
The available evidence suggests that stimulant medication, when appropriately administered, has efficacy as an ADHD treatment for both sexes and across all ages. There are currently too few published papers examining the effects of sex and age to draw strong conclusions about moderation. Further studies of the pharmacodynamics of stimulants on symptoms measured using objective tests in the laboratory or classroom setting need to be undertaken.
Institute for Disorders of Impulse and Attention, School of Psychology, University of Southampton, UK.
Christine
C
Cornforth
Edmund
E
Sonuga-Barke
David
D
Coghill
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000378:metabolism; D000697:Central Nervous System Stimulants / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D012727:Sex Characteristics; D016896:Treatment Outcome; D055815:Young Adult
D000697:Central Nervous System Stimulants