Environmental influences that affect attention deficit/hyperactivity disorder: study of a genetic isolate.
Three independent complex segregation analyses found that the cause of Attention Deficit/Hyperactivity Disorder (ADHD) was the presence of major genes interacting with environmental influences. In order to identify potential environmental risk factors for ADHD in the Paisa community--a very well described, genetically isolated group--we randomly selected a sample of 486 children between 6 and 11 years of age. This group included 200 children with ADHD (149 males and 51 females) and 286 healthy controls (135 males and 151 females). The ADHD DSM-IV diagnosis was obtained using the DICA and BASC evaluation instruments, and the children's mothers or grandmothers filled out a questionnaire on each child's exposure to prenatal, neonatal, and early childhood risk factors. The data were analyzed using cross tabulation and stepwise logistic multiple-regression analyses. Cross tabulation associated ADHD with a variety of factors, including miscarriage symptoms, premature delivery symptoms, maternal respiratory viral infection, moderate to severe physical illness in the mother during gestation, prenatal cigarette and alcohol exposure, neonatal seizures, asphyxia or anoxia, severe neonatal illness, mild speech retardation, moderate brain injury, and febrile seizures (odds ratio >or= 2, P < 0.05). Stepwise logistic multiple-regression analysis also uncovered a block of variables, including male gender, maternal illnesses, prenatal alcohol exposure, mild speech retardation, febrile seizures, and moderate brain injury (odds ratio >or= 2.0, P < 0.05). Future studies on the risk of developing ADHD must include these environmental factors as covariates.
Pineda
David A
DA
Neuropsychology and Conduct Disorder Group, Faculty of Psychology, Master Program of Neuropsychology, University of San Buenaventura, Medellin, Colombia.
Palacio
Luis Guillermo
LG
Puerta
Isabel C
IC
Merchán
Vilma
V
Arango
Clara P
CP
Galvis
Astrid Yuleth
AY
Gómez
Mónica
M
Aguirre
Daniel Camilo
DC
Lopera
Francisco
F
Arcos-Burgos
Mauricio
M
D000328:Adult; D001238:Asphyxia Neonatorum / Q000453:epidemiology; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics*; D002648:Child; D003072:Cognition Disorders / Q000453:epidemiology; D003105:Colombia / Q000453:epidemiology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D006304:Health Status; D006801:Humans; D000860:Hypoxia / Q000453:epidemiology; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors