conditions that arise in the same circumstances in which RAD arises, such as institutionalization or maltreatment. These are principally developmental delays and language disorders associated with neglect. Conduct disorders, oppositional defiant disorder, anxiety disorders, post-traumatic stress disorder and social phobia share many symptoms and are often comorbid with or confused with RAD. Attachment disorder behaviors amongst institutionalized children are correlated with attentional and conduct problems and cognitive levels but nonetheless appear to index a distinct set of symptoms and behaviors. History Reactive attachment disorder first made its appearance in standard nosologies of psychological disorders in DSM-III, 1980, following an accumulation of evidence on institutionalized children. The criteria included a requirement of onset before the age of 8 months and was equated with failure to thrive. Both these features were dropped in DSM-III-R, 1987. Instead, onset was changed to being within the first 5 years of life and the disorder itself was divided into two subcategories, inhibited and disinhibited. These changes resulted from further research on maltreated and institutionalized children and remain in the current version, DSM-IV, 1994, and its 2000 text revision, DSM-IV-TR, as well as in ICD-10, 1992. Both nosologies focus on young children who are not merely at increased risk for subsequent disorders but are already exhibiting clinical disturbance. The broad theoretical framework for current versions of RAD is attachment theory, based on work conducted from the 1940s to the 1980s by John Bowlby, Mary Ainsworth and René Spitz. Attachment theory is a framework that employs psychological, ethological and evolutionary concepts to explain social behaviors typical of young children. Attachment theory focuses on the tendency of infants or children to seek proximity to a particular attachment figure (familiar caregiver), in situations of alarm or distress, behavior which appears to have survival value. This is known as a discriminatory or selective attachment. Subsequently, the child begins to use the caregiver as a base of security from which to explore the environment, returning periodically to the familiar person. Attachment is not the same as love and/or affection although they are often associated. Attachment and attachment behaviors tend to develop between the ages of six months and three years. Infants become attached to adults who are sensitive and responsive in social interactions with the infant, and who remain as consistent caregivers for some time. Caregiver responses lead to the development of patterns of attachment, that in turn lead to internal working