Intellectual disability

Intellectual disability refers to a disorder with onset during a patient’s developmental period that affects their intellect and adaptive functioning (i.e. functioning independently). It is graded by the DSM-5 as mild, moderate, severe, and profound.

Mild

• Conceptual domain: support needed in academic skills to match peers; adults have impairment in abstract thinking, executive function, memory, functional use of academic skills (as with reading and money management); problems are approached concretely
• Social domain: Immature compared to peers, may miss social cues, tend to be more concrete, there may be difficulties regulating emotion/behavior; at risk for being manipulated by others
• Practical domain: May function age appropriately in personal care, need some support with complex daily living tasks (grocery shopping, transportation, home and child-care organizing, money management; may be employed in jobs that do not require conceptualization; require help with medical and legal decisions

Moderate

• Conceptual domain: academic skills are that of an elementary school level; requires assistance with conceptual tasks required in daily life, others may take over this responsibility fully
• Social domain: markedly different from peers, spoken language is much less complex. May not perceive social cues accurately. Capacity for relationships in family and friends, sometimes romantic. Significant communicative support is needed for work settings.
• Practical domain: after extended teaching can care for personal needs (eating, dressing, elimination, hygiene), and basic chores, though reminders may be needed. Independent employment in jobs with limited conceptual / communication skills with significant support from coworkers. Recreational skills can be developed.

Severe

• Conceptual domain: limited conceptual skills, little understanding of written language or concepts involving numbers, time, money; requires extensive supports for problem solving
• Social domain: speech is limited to certain words or phrases; understand simple speech and gestures; relationships w/ familiar people are a source of pleasure and help
• Practical domain: requires support for all ADLs, requires supervision at all times, cannot make responsible decisions regarding their well-being or safety

Profound

• Conceptual domain: conceptual skills are limited to physical rather than symbolic content; limited use of basic objects, matching and sorting skills may be acquired
• Social domain: nonverbal, nonsymbolic communication; limited understanding of speech or gestures; enjoys relationships w/ well known people (i.e. parents)
• Practical domain: dependent on others for all aspects of daily physical care, health, and safety (though can participate in some activities)

Down syndrome

Fragile X syndrome

Rett syndrome

References

American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-5 (5th ed.). (American Psychiatric Association).