Appendix A: DSM-5 Diagnostic Criteria for Intellectual Disability (Intellectual Developmental Disorder)
Intellectual disability (intellectual developmental disorder) is a disorder with onset during the developmental period that includes both intellectual and adaptive functioning deficits in conceptual, social and practical domains. The following three criteria must be met:
- Deficits in intellectual functions, such as reasoning, problem solving, planning, abstract thinking, judgment, academic learning, and learning from experience, confirmed by both clinical assessment and individualized, standardized intelligence testing.
- Deficits in adaptive functioning that result in failure to meet developmental and socio-cultural standards for personal independence and social responsibility. Without ongoing support, the adaptive deficits limit functioning in one or more activities of daily life, such as communication, social participation, and independent living, across multiple environments, such as home, school, work and community.
- Onset of intellectual and adaptive deficits during the developmental period.
The diagnostic term intellectual disability is the equivalent term for the ICD-11 diagnosis of intellectual developmental disorders. Although the term intellectual disability is used throughout this manual, both terms are used in the title to clarify relationships with other classification systems. Moreover, a federal statute in the United States (Public Law 111-256, Rosa's Law) replaces the term mental retardation with intellectual disability, and research journals use the term intellectual disability. Thus, intellectual disability is the term in common use by medical, educational and other professions and by the lay public and advocacy groups.
The ICD-9-CM code for intellectual disability (intellectual developmental disorder) is 319, which is assigned regardless of the severity specifier. The ICD-10-CM code depends on the severity specifier (see below).
Specify current severity:
The various levels of severity are defined on the basis of adaptive functioning and not IQ scores because it is adaptive functioning that determines the level of supports required. Moreover, IQ measures are less valid in the lower end of the IQ range.
Reprinted with permission from the Diagnostic and Statistical Manual of Mental Disorders, Fifth edition, (Copyright 2013). American Psychiatric Association. All rights reserved. (see p. 33)
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