Intellectual Disability, Biology of

Formerly known as “mental retardation,” intellectual disability is the currently accepted term for individuals who have cognitive impairments as well as deficits in adaptive functioning. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) specifies that the symptoms must emerge during the developmental period (i.e., in infancy or childhood/adolescence) and consist of deficits in intellectual and adaptive functioning that occur in the following domains: conceptual, social, and practical. The presence of the symptoms in multiple domains assures that the deficits are not simply due to environmental or situational factors. The deficits in intellectual functioning may include [Page 834]reasoning, problem solving, planning, abstract thinking, judgment, academic learning, and learning from experience. Identification of intellectual deficits is a clinical process and includes the administration of ...