Attention deficit hyperactivity disorder (ADHD) is one of the most common childhood disorders and at least one-third to one-half will continue through adolescence and adulthood. Moreover it is important the high comorbidity not only in children, but in adolescents and adults. Therefore ADHD becomes especially important when we observe it as a risk factor for the development of another psychopathology that add more complexity to the diagnosis of children and adolescents and also adults, and confers an evolutionary risk throughout the lifetime of the person who suffers from it. A correlational study with a sample of 378 patients diagnosed with ADHD in the childhood between 1988 and 2000 who had initiated treatment after been diagnosed was carried out. 88 patients were evaluated years after (2006) with ages between 18 and 33 years old. 85% of the patients in this study had had combined treatment. The data found in this study show lower comorbidity than other published studies (36.4%), as well as a lower persistence of the complete diagnosis of ADHD in the adulthood (15%). This is a treated population; the results may lead to a possible protector role of the early treatment of ADHD.