Familial clustering of executive functioning in affected sibling pair families with ADHD.
OBJECTIVE
To investigate familial clustering of executive functioning (i.e., response inhibition, fine visuomotor functioning, and attentional control) in attention-deficit/hyperactivity disorder (ADHD)-affected sibling pairs.


METHODS
Fifty-two affected sibling pairs aged 6 to 18 years and diagnosed with ADHD according to DSM-IV performed the Stroop test, go/no-go task, two different fine visuomotor tracking tasks, and a sustained-, divided-, and focused attention task.


RESULTS
Significant correlations (r = 0.4) were found between siblings for response inhibition and attentional control and for fine visuomotor skills that made high demands on executive functioning.


CONCLUSIONS
Response inhibition, higher order controlled fine visuomotor functioning, and attentional control seem to cluster in ADHD-affected siblings. This suggests that these aspects of executive dysfunctioning may reflect an endophenotype of ADHD. Measurement of these executive functions may facilitate the identification of genes involved in ADHD by forming more homogeneous subgroups.
Slaats-Willemse
Dorine
D
Department of Psychiatry, Radboud University Medical Center, and The Academic Center for Child and Adolescent Psychiatry Oost-Nederland, Nijmegen, the Netherlands. dorine.slaats@skjpon.nl
Swaab-Barneveld
Hanna
H
De Sonneville
Leo
L
Buitelaar
Jan
J
D000293:Adolescent; D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology*; D002648:Child; D003072:Cognition Disorders / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D010641:Phenotype; D011597:Psychomotor Performance; D035781:Siblings