Intellectual Disabilities

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.

Two other diagnoses exist under the intellectual disability diagnostic category in the DSM-5: Global Developmental Delay and Unspecified Intellectual Disability.

The following three criteria must be met:

Criterion A

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.

Criterion B

Deficits in adaptive functioning that result in failure to meet developmental and sociocultural 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.

Criterion C

Onset of intellectual and adaptive deficits during the developmental period.

This diagnosis is for individuals under the age of 5 years when the clinical severity level cannot be reliably assessed during early childhood. The diagnosis is given when an individual fails to meet expected developmental milestones in several areas of intellectual functioning, and applies to individuals who are unable to undergo systematic assessments of intellectual functioning, including children who are too young to participate in standardized testing. This category requires reassessment after a period of time.

This diagnosis is for individuals over the age of 5 years when assessment of the degree of intellectual disability (intellectual developmental disorder) by means of locally available procedures is difficult or impossible because of sensory or physical impairments (like blindness, prelingual deafness, locomotor disability, presence of severe problem behaviors, or co-occurring mental disorder). This category should only be used in exceptional circumstances and requires reassessment after a period of time.

For Healthcare Providers