Article Abstract

Intellectual disability: definitions, evaluation and principles of treatment

Authors: Dilip R. Patel, Roger Apple, Shibani Kanungo, Ashley Akkal


Intellectual disability is clinically recognized in childhood and adolescence by deficits in cognitive and adaptive abilities. The prevalence of intellectual disability is 1% in the general population. While most individuals have mild intellectual disability, 6 per 1,000 individuals have severe intellectual disability. In persons with mild intellectual disability a specific underlying etiology is generally not recognized; whereas, a specific genetic or biologic etiology is more likely to be recognized in persons who have severe intellectual disability. The diagnosis of intellectual disability requires clinical evaluation and judgment as well as a formal testing of the cognitive and adaptive functions. Such formal testing is done by individually administered standardized tests. The treatment of persons with intellectual disability at an individual level depends on the identified underlying cause, if any, and appropriate support to allow optimal functioning and independent living. Persons who have severe intellectual disability require life-long intensive supports. In addition to general medical care, persons who have intellectual disability also need interventions in the educational settings, provision of educational remediation and accommodations, and appropriate level of community based support. The management, quality of life and longevity vary depending up on the severity of intellectual disability and adequacy of community based support systems.