Studies | Sample | Epidemiology |
| 135 schoolchildren of 5th, 6th and 7th grades of elementary school. | 3.7% with Attention deficit disorder. 4.7% with Hyperactivity. |
| A cross-sectional with 2,452,107 adults patients aged between 18 and 44, enrolled in a primary care program. | 0.04% |
| Indians of the Karajá tribe aged between 7 and 16 years. | 24.5% |
| 2401 students of both sexes aged between 6 - 12 from 10 different educational centers in Barcelona and the Area of Vallès Occidental. | 12% |
| 84 children aged between 6 and 16 years. | 7% |
| 11,442 participants aged between 18 and 44, from 10 countries. | 3.4% |
| 461 students from 1st to 4th grade, aged between 6 and 12 years. | 13% |
| 7075 participants aged between 18 - 44, from 10 countries. | 3.5% |
| 3199 participants aged 18 - 44 years | 4.4% |
| 16,134 participants born between 1985 and 2000 in Sweden. | 5.3% |
| Students aged between 6 and 16 years old from the city of Lyon, France. | 6.6% |
| 657 schoolchildren between 3 and 13 years old. | 7.9% |
| 92 students aged between 9 to 19 years | 19.5% |
| 304 students of elementary school do College of Application of UFRJ | 8.6% |
| 341 students of both sexes, aged between 4 and 17 years. | 21.5% |
| 1898 students from grades 1 to 4, between the ages of 6 and 12. | 5% |
| 774 public school students aged 6 to 12 years. | 6.7% |
| 362 students in grades 1 to 5. | 16% |
| 801 students aged 6 to 9 years of primary school. | 4.99% |
| Parents and Teachers of 640 children aged between 6 and 11 years. Pais e Professores de 640 com idades entre 6 e 11 anos. | It varied between 5% and 15% depending on the informant. When agreement between parents and teachers was required, prevalence dropped to 2%. |
| 403 pupils from primary school | 17.1% |