[Family environment and attention-deficit hyperactivity disorder].

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 São Gonçalo (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.