title: Perinatal complications in children with attention-deficit hyperactivity disorder and their unaffected siblings.
abstract: OBJECTIVE
  Genetic and nonshared environmental factors (experienced by 1 family member to the exclusion of the others) have been strongly implicated in the causes of attention-deficit hyperactivity disorder (ADHD). Pregnancy, labour/delivery and neonatal complications (PLDNC) have often been associated with ADHD; however, no investigations aimed at delineating the shared or nonshared nature of these factors have been reported. We aimed to identify those elements of the PLDNC that are more likely to be of a nonshared nature.
  
  
  METHODS
  We used an intrafamily study design, comparing the history of PLDNC between children diagnosed with ADHD, according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), and their unaffected siblings. Children with ADHD were recruited from the outpatient, day-treatment program of the Child Psychiatry Department, Douglas Hospital, Montreal. The unaffected sibling closest in age to the child with ADHD was used as a control. The history of PLDNC was assessed using the Kinney Medical and Gynecological Questionnaire and the McNeil-Sjostrom Scale for both children with ADHD and their siblings. Seventy children with ADHD along with 50 of their unaffected siblings agreed to participate in the study. Child Behavior Checklist (CBCL), Continuous Performance Test (CPT) and Restricted Academic Situation Scale (RASS) scores were also used as measures of ADHD symptoms in children with ADHD.
  
  
  RESULTS
  The children with ADHD had significantly higher rates of neonatal complications compared with their unaffected siblings (F4,196 = 3.67, p < 0.006). Furthermore, neonatal complications in the children with ADHD were associated with worse CBCL total and externalizing scores and with poorer performance on the CPT.
  
  
  CONCLUSIONS
  These results suggest that neonatal complications are probably a nonshared environmental risk factor that may be pathogenic in children with ADHD.
authors.affiliation: Department of Psychiatry, Laval University, Québec.
authors.forename: Leila
authors.initials: L
authors.lastname: Ben Amor
authors.forename: Natalie
authors.initials: N
authors.lastname: Grizenko
authors.forename: George
authors.initials: G
authors.lastname: Schwartz
authors.forename: Philippe
authors.initials: P
authors.lastname: Lageix
authors.forename: Chantal
authors.initials: C
authors.lastname: Baron
authors.forename: Marina
authors.initials: M
authors.lastname: Ter-Stepanian
authors.forename: Michael
authors.initials: M
authors.lastname: Zappitelli
authors.forename: Valentin
authors.initials: V
authors.lastname: Mbekou
authors.forename: Ridha
authors.initials: R
authors.lastname: Joober
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000209:etiology* / Q000523:psychology*; D002648:Child; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000523:psychology*; D008297:Male; D007744:Obstetric Labor Complications / Q000523:psychology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000523:psychology*