What is Intellectual Developmental Disorder (IDD) in DSM-5-TR?

A disorder with onset during the developmental period that includes both intellectual and adaptive functioning deficits in the conceptual, social, and practical domains.

Criterion A – What must be present regarding intellectual functions?

Deficits in intellectual functions (e.g., reasoning, problem solving, planning, abstract thinking, judgment, academic learning, learning from experience), confirmed by both clinical assessment and individualized, standardized intelligence testing.

Criterion B – What type of deficits must be present?

Deficits in adaptive functioning that result in failure to meet developmental and sociocultural standards for personal independence and social responsibility.

Criterion B – How do adaptive deficits affect daily life?

Without ongoing support, adaptive deficits limit functioning in one or more activities of daily life (such as communication, social participation, and independent living) across multiple environments (home, school, work, community).

Criterion C – When must the onset of intellectual and adaptive deficits occur?

The onset of intellectual and adaptive deficits must occur during the developmental period (childhood or adolescence).

What are the three domains of adaptive functioning in IDD?

The conceptual (academic) domain, the social domain, and the practical domain.

What does the conceptual (academic) domain involve?

Competence in areas such as memory, language, reading, writing, math reasoning, acquisition of practical knowledge, problem solving, and judgment in novel situations.

What does the social domain involve?

Awareness of others’ thoughts, feelings, and experiences; empathy; interpersonal communication skills; the ability to form and maintain friendships; and social judgment.

What does the practical domain involve?

Learning and self-management across life settings, including personal care, job responsibilities, money management, recreation, self-management of behavior, and organization of school or work tasks.

How is severity specified in IDD in DSM-5-TR?

Severity is specified as Mild (F70), Moderate (F71), Severe (F72), or Profound (F73), based on adaptive functioning in the conceptual, social, and practical domains, not on IQ score alone.