The authors have traced the developmental course of ADHD from childhood to adulthood, showing that it is a bumpy road for many. In early and middle adolescence, relative deficits are seen in academic and social functioning, ADHD symptoms remain problematic in two thirds to three quarters of these children, and antisocial behaviors, in some cases amounting to CD, are common. Many of these same difficulties persist into the late teenage years. Deficits continue to be observed in academic and social domains (compared with controls, probands exhibit lower grades, more courses failed, worse performance on standardized tests, have fewer friends, and are rated less adequate in psychosocial adjustment). About two fifths continue to experience ADHD symptoms to a clinically significant degree. One quarter to one third have a diagnosed antisocial disorder, and two thirds of these individuals are arrested. Also, drug abuse is observed in a significant minority of these youths. Importantly, the greatest risk factor for the development of antisocial behavior and substance abuse by the late teenage years is the maintenance of ADD symptoms. When evaluated in their mid-twenties, dysfunctions are apparent in these same areas. Compared with controls, probands complete less schooling, hold lower-ranking occupations, and continue to suffer from poor self-esteem and social skills deficits. In addition, significantly more probands than controls exhibit an antisocial personality and, perhaps, a substance use disorder in adulthood. Furthermore, many do not outgrow all facets of their childhood syndrome. These relative deficits, however, do not tell the whole story of the ADHD child's adult fate. Indeed, nearly all probands were gainfully employed. Furthermore, some had achieved a higher-level education (e.g., completed Master's degree, enrolled in medical school) and occupation (e.g., accountant, stock broker). In addition, a full two thirds of these children showed no evidence of any mental disorder in adulthood. In conclusion, although ADHD children, as a group, fare poorly compared with their non-ADHD counterparts, the childhood syndrome does not preclude attaining high educational and vocational goals, and most children no longer exhibit clinically significant emotional or behavioral problems once they reach their mid-twenties.