Intellectual Disability: Comorbidity

The core concept of comorbidity (derived from the Latin words co and morbidus, and approximately translated as “along with diseased condition”) is the presence of more than one distinct condition in an individual. However, comorbidity is more commonly defined in relation to one specific primary condition, referred to as the index condition, and includes any distinct additional entity that has existed or may occur during the clinical course of a patient who has the index condition under study. The choice of which condition to designate as “index” and which conditions to designate as “comorbid” may vary depending on the research question or clinical situation and does not imply causality, temporal relationship, or relative importance of the conditions. The nature of comorbidity may include diseases, disorders, ...