RESUMEN
BACKGROUND: Attention-deficit hyperactivity disorder (ADHD) is the most common behavioral disorder in children. It affects not only the subjects but also their families and society. The purpose of this study was to determine the prevalence of ADHD in primary school children in South Vietnam, especially Vinh Long province. METHOD: Children were chosen randomly from primary schools in Vinh Long from February to March in 2009 in a cross-sectional study to determine the prevalence of ADHD using the ADHD Rating Scale-IV for parents/caregivers and teachers. ADHD Rating Scale-IV was based on DSM-IV for diagnosis of ADHD. RESULTS: A total of 600 children were chosen and 1200 reports were collected from parents/caregivers and teachers. The prevalence rate of ADHD was 7.7%. The rates of the predominantly inattentive type, predominantly hyperactive type and combined type were 1.7%, 5% and 1%, respectively. The difference in sex was not significant across all subtypes. The prevalence of ADHD in urban children was 2.2-fold that in rural children. CONCLUSION: The prevalence of ADHD in primary school children in Vinh Long, southern Vietnam, is in the same range as other regions in the world. Therefore, awareness of ADHD needs to be raised, to ensure suitable psychiatric care for children.