Ambiente familiar e transtorno de déficit de aten？？o e hiperatividade

objective: to analyze factors associated with attention-deficit and hyperactivity disorder in children. methods: this is a longitudinal study about behavior problems in schoolchildren that was carried out in the city of s？o gon？alo (southeastern brazil) in 2005. a total of 479 students from public schools was analyzed, selected through three-stage cluster sampling. the child behavior checklist was used to measure the outcome. a questionnaire was administered to parents/guardians concerning the exposure factors, which were: child's and family's profile, family relationship variables, physical and psychological violence. the log-binomial regression model with a hierarchical approach was employed in the analysis. results: higher intelligence quotient was inversely associated with the frequency of the disorder (pr=0.980 [95%ci 0.963;0.998]). the prevalence of the disorder in the children was higher when there was family dysfunction than among families with a better way of relating (pr=2.538 [95%ci 1.572; 4.099]). children who suffered verbal abuse from the mother had a prevalence 3.7 times higher than the ones not exposed to this situation in the last year (pr=4.7 [95%ci 1.254;17.636]). conclusions: negative family relationships are associated with symptoms of attention-deficit and hyperactivity disorder. its association with the intelligence quotient reiterates the importance of the genetic and environmental basis at the origin of the disorder.