RESUMO
INTRODUCTION: Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioural disorder among schoolchildren. It may persist into adulthood and affect performance in the academic, social, occupational and familial spheres, and increase the use and abuse of alcohol and psychoactive substances and the risk of having an accident. Its prevalence throughout the world varies widely and further knowledge about this situation would be valuable for the development of policies in the sector of education. AIMS: The aim of this research was to determine the prevalence of ADHD and its distribution according to subtypes in schoolchildren from Sabaneta, Antioquia, Colombia, in 2001. SUBJECTS AND METHODS: The analysis involved a cross-sectional descriptive study using a representative randomised multistage sample (which was proportional to the size of the groups) of schoolchildren between 4 and 17 years old. Measurement was performed in two stages, first by application of a screening form according to DSM IV criteria, and later a structured interview, Conners' and Intelligence tests. RESULTS: Prevalence was found to be 20.4% and 15.8% if only children with an intelligence quotient of 80 or above were considered. The combined subtype was the most frequent, with 9.6%. In public schools it was 16.2%, private 15.3%, age group from 7-11 years 16.9%, 12-17 years old 14.2%, males 20.9%, females 10.1%, low 14.7%, medium 17.4% and high socioeconomic level 10.7%, with a male to female prevalence ratio of 3.88 to 1. CONCLUSIONS: Prevalence of ADHD in the school population in a municipality in the Metropolitan Area of Medellin, Colombia, is high. The most frequent subtype was the combined type, which was predominant in males, had repercussions on academic performance and low proportions of pharmacological interventions for the disorder (15%). Programmes must be developed for the detection of this problem and subsequent intervention in the school population.