"The New York Times" has labeled Breggin as the nation's best-known Attention-deficit hyperactivity disorder (ADHD) critic. As early as 1991 he sardonically coined the acronym DADD, stating, "... most so-called ADHD children are not receiving sufficient attention from their fathers who are separated from the family, too preoccupied with work and other things, or otherwise impaired in their ability to parent. In many cases the appropriate diagnosis is Dad Attention Deficit Disorder (DADD)". Breggin has written two books specifically on the topic entitled, "Talking Back to Ritalin" and "The Ritalin Factbook". In these books he has made controversial claims, such as "Ritalin 'works' by producing malfunctions in the brain rather than by improving brain function. This is the only way it works".