Objective: The purpose of this study was to examine the effects of a wide range of obstetrical and neonatal complications as well as socioeconomic variables on the behaviors characterized by attention-deficit hyperactivity disorder, conduct disorder, and oppositional defiant disorder.
Method: Data were collected on 7- to 8-year old twins, using multiple instruments assessing many areas of individual and family functioning. The influence of several aspects of prenatal care, labor and delivery, and early life were considered as well as indicators of socioeconomic status, such as family income and maternal education.
Results: The observed associations were stronger for attention-deficit hyperactivity disorder than conduct disorder symptoms and stronger for females than males. Family income and gender significantly predicted both behavioral outcomes, whereas birth weight predicted attention-deficit hyperactivity disorder symptoms only. However, the presence of attention-deficit hyperactivity disorder and conduct symptom behaviors were not associated with an occurrence of more obstetrical or neonatal complications as indicated by hierarchical linear modeling analyses.
Conclusions: By school age, behavioral problems related to inattention, impulsivity, hyperactivity, defiance, and conduct are relatively unaffected by general adversity in the neonatal and perinatal periods.