The philosopher of science Ian Hacking writes that our world is one of classifications, and these classifications, or names, have a particular effect when they refer to the behavior of people. This article seeks to present what Attention-Deficit Hyperactivity Disorder (ADHD) is and how it appeared in children. Then, it discusses the conversion of undesirable behaviors into symptoms which underlies the identification of ADHD as a disease. From these considerations, a more general model about the interaction between classifications and classified people is proposed, based on Hacking's distinction between indifferent and interactive kinds, and also on the concept of looping effect proposed by that author. Finally, the model is applied to ADHD, and some considerations are made regarding the concept of social control put forth by Peter Conrad.
ADHD; Looping effect; Classifying people; Childhood medicalization
