title: [The frequency of some factors in pregnancy and delivery for Icelandic children with ADHD].
abstract: OBJECTIVE
  ADHD is a well known psychiatric disorder that begins in childhood and frequently persists into adulthood. In the last decade numerous studies have shown the importance of genetic factors in the etiology of ADHD. However other etiological factors seem to be involved. The aim of this study was to examine the frequency of some possible etiological factors for ADHD in Icelandic children diagnosed with ADHD. The study is descriptive.
  
  
  METHODS
  The participants were 196 children referred for suspected ADHD to the outpatient unit of the Department of Child and Adolescent Psychiatry, Landspitali University Hospital during a 2 year period 1998-1999. The participants had either ICD-10 or DSM-IV hyperkinetic disorder and/or ADHD and the information was obtained from patient case notes. Information provided by parents in a questionnaire concerning health in pregnancy and the perinatal period was retrospectively analysed.
  
  
  RESULTS
  The main results show statistically significant increased risk for ADHD associated with several factors such as low birthweight, young age of the mother at the time of the child's birth and Caesarean section, compared with reference groups such as mean values in all of the community. Other factors such as birthweight, alcohol or tobacco use in pregnancy, use of medication in pregnancy or vacuum extraction did not show statistically significant association with ADHD.
  
  
  CONCLUSIONS
  The results indicate as some studies from other countries have suggested that an association exists between a number of factors in pregnancy, delivery and perinatal period and ADHD, even though there is still not enough evidence to confirm definite etiological factors.
authors.affiliation: Dept of Child and Adolesent Psychiatry, Landspítali University Hospital, Hringbraut, 101 Reykjavík, Iceland. margval@landspitali.is
authors.forename: Margrét
authors.initials: M
authors.lastname: Valdimarsdóttir
authors.forename: Agnes Hulda
authors.initials: AH
authors.lastname: Hrafnsdóttir
authors.forename: Páll
authors.initials: P
authors.lastname: Magnússon
authors.forename: Olafur O
authors.initials: OO
authors.lastname: Gudmundsson
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology* / Q000209:etiology*; D002585:Cesarean Section; D002648:Child; D005260:Female; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D011248:Pregnancy Complications; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires