How does DSM-5 define intellectual disability?
A deficit in intellectual and adaptive functioning of an individual (American Psychiatric Association, 2013)
| What are the signs and symptoms of intellectual disability according to DSM-5? | How common is intellectual disability? | |
| ¾ Limitation in spoken language – vocabulary and grammar – conceptual domain¾ Limitation in conceptual skills such as understanding written language – social domain
¾ Dependence for activities of daily living – dressing, bathing, cooking meals, elimination – practical domain ¾ Other criteria: symptoms begin during the period of development (American Psychiatric Association, 2013) |
¾ Affects one percent of the population (American Psychiatric Association, 2013)¾ In the US, it affected about 3.5% (CDC, 2019)
¾ More common among males than females, with 1.6/1 for mild to 1.2/1 for severe cases (American Psychiatric Association, 2013) ¾ About six in every thousand cases are severe ¾ Commonly diagnosed among older children (CDC, 2019) ¾ No significant racial predilection |
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| What are the risk factors for intellectual disability? | What is the Development and course of intellectual disability | |
| · Can be classified as genetic or physiological· Genetic factors – chromosomal disorders, inborn errors of metabolism, maternal disease
· Physiological factors can be antenatal, natal, or postnatal · Antenatal – toxins and alcohol · Natal – traumatic labor, neonatal encephalopathy · Postnatal – infections (meningitis), traumatic brain injury, child abuse, hypoxic-ischemic injury, toxic metabolic syndromes, seizure disorders, demyelinating disorders, and chronic social deprivations |
· Deficient brain development leading to slow or absent neurodevelopment· Deficits in language and motor development are diagnosed first
· The disease does not progress, but there is absent development of neurological and behavioral milestones · Diagnosis can be made as early as 2 years of age (American Psychiatric Association, 2013) · Lack of achievement of social and behavioral skills are seen · Sometimes, the risks lead to the loss of achieved milestones |
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| Diagnostics and lab | How do I evaluate further the suspected cases? | |
| · Clinical and mental state examinations are required· Standardized intelligence tests are used to assess the intelligence quotient (IQ)
· Chromosome analysis to screen chromosomal diseases · Urine and blood analysis to screen comorbidities · Metabolic screening |
· Family pedigree – three generations· Evaluate associated medical illnesses – seizures, cerebral palsy
· Cultural evaluation · Assess the home environment · Assess the availability of community reserves |
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| What are the possible differential diagnoses for intellectual disability? SCAM -mnemonic |