Disorganization is independent of general intelligence. It is quite possible for an individual to be extremely bright on standard measures of intelligence and still have severe impairments of executive functions, such as those often seen in ADD.
An individual's overall level of "smarts," as measured by standard IQ tests, appears to have little to do with whether he or she meets the diagnostic criteria for ADD. Some of my ADD patients are extremely bright, employed as university professors, scientists, physicians, attorneys, and senior executives.
This article comes from the April/May 2006 issue of ADDitude.