The vast majority (85 percent) of adults with AD/HD are undiagnosed and untreated.

Compared with adults who don't take medication for AD/HD, those taking medication are less likely to get into a car accident (29 percent vs. 20 percent), a fight (24 percent vs. 11 percent) or abuse drugs (15 percent vs. 7 percent), according to a recent survey by Harris Interactive.

In addition, AD/HD affects other major aspects of adults' lives, including their ability to follow through on things (85 percent), succeed in the workplace (64 percent) and handle stress (64 percent).

AD/HD affects three percent to seven percent of school-age children. About 60 percent of children with the disorder carry their symptoms into adulthood.