title: Familial association and frequency of learning disabilities in ADHD sibling pair families.
abstract: In a sample of 235 families with at least two children with Attention-Deficit/ Hyperactivity Disorder (ADHD), the frequency and familial association of learning disabilities (LD) were assessed. Familiality was examined both between sibling pairs and between parents and their children. Two methods for defining LD, a discrepancy-based and a low-achievement model, were employed to examine the occurrence of LD in this sample. The specific types of LD examined included Reading Disability (RD), Math Disability (MD), and Writing Disability (WD). The prevalence rates were highest for RD, followed by WD then MD. The two definitions of LD yielded similar prevalence rates but identified different groups of children with vastly different IQ scores. Strong familial association was demonstrated for RD both between sibling pairs and between parents and children, with weaker association for WD. There was evidence of nonrandom mating for LD among parents, but not for ADHD or for ADHD + LD. Despite the high comorbidity of ADHD and LD among parents, the presence of ADHD in the parents did not predict child LD supporting independent familial factors underlying ADHD and LD.
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, Semel Institute of Neuroscience and Human Behavior, University of California, 300 UCLA Medical Plaza, Suite 1416, Los Angeles, CA 90095-6967, USA. mdelhomme@mednet.ucla.edu
authors.forename: Melissa
authors.initials: M
authors.lastname: Del'Homme
authors.forename: Tae S
authors.initials: TS
authors.lastname: Kim
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Loo
authors.forename: May H
authors.initials: MH
authors.lastname: Yang
authors.forename: Susan L
authors.initials: SL
authors.lastname: Smalley
mesh_terms: D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000523:psychology*; D002648:Child; D004522:Educational Status; D005190:Family; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D007407:Interviews as Topic; D007859:Learning Disabilities / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D010287:Parent-Child Relations; D011932:Reading; D035781:Siblings; D014888:Wechsler Scales; D014956:Writing