摘要：Attention Deficit Hyperactivity Disorder is a multidetermined phenomenon of high incidence affecting children, adolescents and adults worldwide, resulting in impairment in several areas of development such as social relationships, academic performance, professional and romantic relationships. The objective of this study was to review systematically the literature to verify the epidemiological picture of the disorder under three main aspects: 1) what is the ADHA definition; 2) what is the epidemiology of the disorder; and 3) what are the instruments used for diagnostic evaluation. The search was performed in the database Periódicos CAPES, PsicInfo, and MedLine using the keywords “Epidemiology and ADHD” and its correlation in English and Spanish. 331 articles, of which only 21 met the inclusion criteria, were retrieved. The results suggest that there is a consensus on the ADHD definition; however epidemiological data ranged from 0.04% to 24.5%. The studies also varied as to the use of diagnostic instruments, being more used the DSM-IV criteria.
