title: Simplex and multiplex stratification in ASD and ADHD families: a promising approach for identifying overlapping and unique underpinnings of ASD and ADHD?
abstract: Autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (ADHD) are highly heterogeneous neuropsychiatric disorders, that frequently co-occur. This study examined whether stratification into single-incidence (SPX) and multi-incidence (MPX) is helpful in (a) parsing heterogeneity and (b) detecting overlapping and unique underpinnings of the disorders. ASD and ADHD traits were measured in 56 ASD/31 ADHD SPX families, 59 ASD/171 ADHD MPX families and 203 control families. In ASD but not ADHD, behavioral traits were less elevated in SPX than MPX unaffected relatives, suggesting that SPX-MPX stratification may thus help parse ASD, but not ADHD heterogeneity. Particularly unaffected relatives from MPX ASD/ADHD families displayed elevated trait levels of both disorders, indicating shared (multifactorial) underpinnings underlying ASD and ADHD in these families. Cross-disorder traits were highest in MPX ASD unaffected siblings.
authors.affiliation: Karakter, Child and Adolescent Psychiatry University Centre Nijmegen, Reinier Postlaan 12, 6525 GC, Nijmegen, The Netherlands, Anoek.Sluiter-Oerlemans@radboudumc.nl.
authors.forename: Anoek M
authors.initials: AM
authors.lastname: Oerlemans
authors.forename: Catharina A
authors.initials: CA
authors.lastname: Hartman
authors.forename: Yvette G E
authors.initials: YG
authors.lastname: De Bruijn
authors.forename: Daphne J
authors.initials: DJ
authors.lastname: Van Steijn
authors.forename: Barbara
authors.initials: B
authors.lastname: Franke
authors.forename: Jan K
authors.initials: JK
authors.lastname: Buitelaar
authors.forename: Nanda N J
authors.initials: NN
authors.lastname: Rommelse
mesh_terms: D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000175:diagnosis / Q000523:psychology*; D002675:Child, Preschool; D005191:Family Characteristics; D005192:Family Health; D005260:Female; D006801:Humans; D008297:Male; D010290:Parents / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D035781:Siblings / Q000523:psychology*; D055815:Young Adult