Differential effects of atomoxetine on executive functioning and lexical decision in attention-deficit/hyperactivity disorder and reading disorder.
OBJECTIVE
The effects of a promising pharmacological treatment for attention-deficit/hyperactivity disorder (ADHD), atomoxetine, were studied on executive functions in both ADHD and reading disorder (RD) because earlier research demonstrated an overlap in executive functioning deficits in both disorders. In addition, the effects of atomoxetine were explored on lexical decision.


METHODS
Sixteen children with ADHD, 20 children with ADHD + RD, 21 children with RD, and 26 normal controls were enrolled in a randomized placebo-controlled crossover study. Children were measured on visuospatial working memory, inhibition, and lexical decision on the day of randomization and following two 28-day medication periods.


RESULTS
Children with ADHD + RD showed improved visuospatial working memory performance and, to a lesser extent, improved inhibition following atomoxetine treatment compared to placebo. No differential effects of atomoxetine were found for lexical decision in comparison to placebo. In addition, no effects of atomoxetine were demonstrated in the ADHD and RD groups.


CONCLUSIONS
Atomoxetine improved visuospatial working memory and to a lesser degree inhibition in children with ADHD + RD, which suggests differential developmental pathways for co-morbid ADHD + RD as compared to ADHD and RD alone.


BACKGROUND
B4Z-MC-LYCK, NCT00191906; http://clinicaltrials.gov/ct2/show/NCT00191906.
de Jong
Christien G W
CG
Department of Clinical Neuropsychology, VU University Amsterdam, Amsterdam, The Netherlands. cgw.de.jong@psy.vu.nl
Van De Voorde
Séverine
S
Roeyers
Herbert
H
Raymaekers
Ruth
R
Allen
Albert J
AJ
Knijff
Simone
S
Verhelst
Helene
H
Temmink
Alfons H
AH
Smit
Leo M E
LM
Rodriques-Pereira
Rob
R
Vandenberghe
Dirk
D
van Welsen
Inge
I
ter Schuren
Liesbeth
L
Al-Hakim
Mazim
M
Amin
Azad
A
Vlasveld
Laurens
L
Oosterlaan
Jaap
J
Sergeant
Joseph A
JA
D018759:Adrenergic Uptake Inhibitors / Q000627:therapeutic use*; D000069445:Atomoxetine Hydrochloride; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000188:drug therapy* / Q000523:psychology; D002648:Child; D018592:Cross-Over Studies; D003657:Decision Making / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004410:Dyslexia / Q000150:complications / Q000188:drug therapy* / Q000523:psychology; D056344:Executive Function / Q000187:drug effects*; D006801:Humans; D007266:Inhibition, Psychological; D008568:Memory / Q000187:drug effects; D009483:Neuropsychological Tests; D011437:Propylamines / Q000627:therapeutic use*; D011932:Reading; D016896:Treatment Outcome
D018759:Adrenergic Uptake Inhibitors; D011437:Propylamines; D000069445:Atomoxetine Hydrochloride