Disease Description (Causes and Symptoms)
- Definition: Intellectual disability is a condition that begins during the developmental period and involves deficits in intellectual functioning (such as IQ) and adaptive functioning (such as personal independence and social responsibility). Limitations in conceptual, social, and practical domains are also present (DSM-5 criteria).
- Pathophysiology summary: Genetic, metabolic, infectious, hypoxic, traumatic, and other factors that affect brain development and function interfere with neurodevelopment, resulting in reduced cognitive abilities and impaired adaptation to daily life.
- Main causes
- Congenital and genetic: Down syndrome, chromosomal abnormalities, metabolic disorders (e.g., phenylketonuria), congenital hypothyroidism, etc.
- Factors during pregnancy: Infections such as rubella and syphilis, exposure to certain medications, alcohol, or radiation
- Factors before and around delivery: Fetal hypoxia, brain injury during delivery
- Acquired factors: Encephalitis or meningitis during infancy or early childhood, poisoning, malnutrition, etc.
- In many cases, the cause is not clear
- Symptoms (main clinical manifestations)
- Developmental delay (motor skills, language, and learning)
- Impaired intellectual functioning (reasoning, problem-solving, abstract thinking, etc.)
- Limitations in adaptive behavior (self-care, interpersonal relationships, job performance, etc.)
- Emotional disorders, behavioral problems (impulsivity, aggression, withdrawal), language disorders, and social deficits
- Severity classification (general criteria): Mild (IQ 50–69), moderate (35–49), severe (20–34), profound (<20)
Treatment Methods
- Treatment goals: Improve functioning (adaptive abilities and independence), manage problem behaviors and co-occurring mental disorders, and connect the patient with family and social support
- Standard approach: Multidisciplinary and individualized intervention
- Educational intervention: Special education, individualized education programs (IEPs), learning support
- Behavioral therapy: Behavior modification techniques, social skills training
- Speech therapy, occupational therapy, and physical therapy: Improving communication, activities of daily living, and motor function
- Vocational rehabilitation and life-skills training: Support for independence and vocational connections in adulthood
- Family education and caregiving support: Setting realistic expectations and providing parenting-skills education
- Medication treatment
- There are no medications that improve intelligence itself
- For co-occurring psychiatric symptoms (depression, anxiety, ADHD, aggressive behavior, psychosis, etc.), medications appropriate for the symptoms (e.g., antidepressants, stimulants, antipsychotics, etc.) may be used cautiously
- Medication selection, dosage, effectiveness, and side-effect management should be discussed with a mental health specialist
- Procedures/Surgery
- When surgical treatment is required for a specific cause (e.g., hydrocephalus), surgery may be performed according to the cause
- Lifestyle management and precautions
- Safety management (preventing accidents such as falls, burns, and water-related accidents), infection prevention (vaccination), and maintaining regular sleep, nutrition, and daily routines
- Professional evaluation and intervention are necessary when behavioral problems are severe
- Provide information about and connect the patient with legal and social rights and services (educational support and welfare services for people with disabilities)
- Risk of complications
- Co-occurring psychiatric disorders (depression, anxiety, behavioral disorders), reduced learning and occupational functioning, and increased risk of abuse and exploitation
Checkpoints Before an Outpatient Visit (Including Sample Questions)
- Items to prepare
- A list of currently taken medications and dosages (including prescription and nonprescription medications and supplements)
- Copies of previous test results (intelligence tests, developmental assessments, genetic tests, brain imaging, etc.)
- School and therapy reports (IEP and evaluations by educational institutions)
- Developmental history (timing of first smile, rolling over, sitting, speaking, etc.) and records of symptom onset and changes
- Notes on the frequency and triggers of problem behaviors and attempted interventions
- Whether there is a history of seizures (epilepsy) and related records
- Caregiver contact information and information about needed support
- Examples of useful symptom records for the visit (prepare as questions)
- When did the developmental delays or behavioral problems begin, and what were they?
- What activities can the patient perform independently in daily life (getting dressed, eating, using the toilet, etc.)?
- Have there been recent changes in behavior, sleep, or appetite? Do symptoms worsen in specific situations?
- Have any tests or treatments (educational or medication) been received previously? How effective were they?
Examples of General Questions to Ask the Doctor
- How are this patient's intellectual level and adaptive functioning assessed?
- Are there any additional tests you recommend (genetic tests, metabolic tests, brain imaging, etc.)?
- What treatment do you recommend for the current symptoms (behavioral problems, emotional symptoms, etc.)?
- If medication is prescribed, what are the expected effects and main side effects?
- How can the patient be connected with school, welfare, and rehabilitation services?
- What is the long-term prognosis regarding education, employment, and the possibility of independent living?
Examples of Tailored Questions by Condition
- What are this child's (or patient's) IQ and level of adaptive functioning, and in which areas is independent-living training needed or possible?
- What additional tests do you recommend to identify the current cause (genetic, metabolic, or structural abnormality) (e.g., chromosomal testing, a gene panel, metabolic testing, or brain MRI)?