Time reproduction in children with ADHD and their nonaffected siblings.
OBJECTIVE
Time reproduction is deficient in children with attention-deficit/hyperactivity disorder (ADHD). Whether this deficit is familial and could therefore serve as a candidate endophenotype has not been previously investigated. It is unknown whether timing deficits are also measurable in adolescent children with ADHD and nonaffected siblings.


METHODS
These issues were investigated in 226 children with ADHD, 188 nonaffected siblings, and 162 normal controls ages 5 to 19. Children participated in a visual and auditory time reproduction task. They reproduced interval lengths of 4, 8, 12, 16, and 20 seconds.


RESULTS
Children with ADHD and their nonaffected siblings were less precise than controls, particularly when task difficulty was systematically increased. Time reproduction skills were familial. Time reproduction deficits were more pronounced in younger children with ADHD than in older children. Children with ADHD could be clearly dissociated from control children until the age of 9. After this age, group differences were somewhat attenuated, but were still present. Differences between nonaffected siblings and controls were constant across the age range studied. Deficits were unaffected by modality.


CONCLUSIONS
Time reproduction may serve as a candidate endophenotype for ADHD, predominantly in younger children with (a genetic risk for) ADHD.
Rommelse
Nanda N J
NNJ
Drs. Rommelse, Dr. Oosterlaan, and Dr. Sergeant are with the Department of Clinical Neuropsychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands; Dr. Buitelaar is with the Department of Psychiatry, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands; and Dr. Faraone is with the Departments of Psychiatry and Neuroscience and Physiology, SUNY-Upstate Medical University, Syracuse, NY. Electronic address: nnj.rommelse@psy.vu.nl.
Oosterlaan
Jaap
J
Drs. Rommelse, Dr. Oosterlaan, and Dr. Sergeant are with the Department of Clinical Neuropsychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands; Dr. Buitelaar is with the Department of Psychiatry, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands; and Dr. Faraone is with the Departments of Psychiatry and Neuroscience and Physiology, SUNY-Upstate Medical University, Syracuse, NY.
Buitelaar
Jan
J
Drs. Rommelse, Dr. Oosterlaan, and Dr. Sergeant are with the Department of Clinical Neuropsychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands; Dr. Buitelaar is with the Department of Psychiatry, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands; and Dr. Faraone is with the Departments of Psychiatry and Neuroscience and Physiology, SUNY-Upstate Medical University, Syracuse, NY.
Faraone
Stephen V
SV
Drs. Rommelse, Dr. Oosterlaan, and Dr. Sergeant are with the Department of Clinical Neuropsychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands; Dr. Buitelaar is with the Department of Psychiatry, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands; and Dr. Faraone is with the Departments of Psychiatry and Neuroscience and Physiology, SUNY-Upstate Medical University, Syracuse, NY.
Sergeant
Joseph A
JA
Drs. Rommelse, Dr. Oosterlaan, and Dr. Sergeant are with the Department of Clinical Neuropsychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands; Dr. Buitelaar is with the Department of Psychiatry, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands; and Dr. Faraone is with the Departments of Psychiatry and Neuroscience and Physiology, SUNY-Upstate Medical University, Syracuse, NY.
D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology*; D001307:Auditory Perception; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D010468:Perceptual Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D010641:Phenotype; D035781:Siblings; D013998:Time Perception; D014796:Visual Perception