I think I've mentioned before that there is fMRI evidence that children with ADHD have brain development in the frontal lobes that resembles that of much younger children (often about 3 years younger), which lags for many years, until it appears to "catch up" around late adolescence. If you think of their executive functions as being typical of a child about 3 years younger, then the level of scaffolding that you may have to do for daily living skills is not particularly strange, especially since their age-appropriate tasks require a much higher degree of organization and self-monitoring than would those for a younger child. (The later brain development, btw, is also postulated to contribute to the higher degree of creative and entrepeneurial thinking found in persons identified as ADHD, as it's like having age-appropriate (i.e., older) cognition, but with the fertile creativity of a young child.)
