Disinhibited attachment disorder (DAD) according to the International Classification of Diseases (ICD-10), is defined as:"A particular pattern of abnormal social functioning that arises during the first five years of life and that tends to persist despite marked changes in environmental circumstances, e.g. diffuse, nonselectively focused attachment behaviour, attention-seeking and indiscriminately friendly behaviour, poorly modulated peer interactions; depending on circumstances there may also be associated emotional or behavioural disturbance." – F94.2 of the ICD-10.
Disinhibited attachment disorder is a subtype of the ICD-10 category F94, "Disorders of social functioning with onset specific to childhood and adolescence". The other subtype of F94 is reactive attachment disorder of childhood (RAD – F94.1). A similar disorder is institutional syndrome.
Within the ICD-10 category scheme, disinhibited attachment disorder specifically excludes Asperger syndrome (F84.5), hospitalism in children (F43.2), and attention deficit hyperactivity disorder (F90.-).