Mental Retardation (Intellectual Disability): DSM-5 EPPP Lecture Video

The video below is the section for Mental Retardation (Intellectual Disability) from Part 5 of TSM’s lecture series on DSM-5 and the EPPP, followed by a transcript. This lecture series aims to equip those preparing for the EPPP with everything you need to know about the impact DSM-5 will be having on the EPPP. To watch all of Part 5, click HERE. To watch earlier lectures in this series, or register for our webinar series on DSM-5 and the EPPP, click HERE.

Transcript of DSM-5 EPPP Lecture Video: Mental Retardation (Intellectual Disability)

NARRATIVE DEFINITION:
The new term for Mental Retardation in the DSM-5 is Intellectual Disability (Intellectual Developmental Disorder). Assessment will need to include both cognitive capacity (IQ) and adaptive functioning, and the severity specifiers are based on adaptive functioning rather than IQ. DSM-5 is meant to parallel the World Health Organization’s International Classification of Diseases (ICD) and though the current edition of the ICD uses the term Intellectual Disability, the new ICD-11, to be released in 2015, will use the term Intellectual Developmental Disorder. This is why the DSM-5 uses the current term Intellectual Disability with the future term (Intellectual Developmental Disorder) in parentheses to be changed when the ICD changes.

A diagnosis of Intellectual Disability (Intellectual Developmental Disorder) requires that three criteria be met: 1) deficits in intellectual functions confirmed by both clinical assessment and individualized, standardized testing (functions such as reasoning, problem-solving, abstract thinking, academic learning, learning from experienced); 2) marked deficits in adaptive functioning that lead to inability to meet developmental and sociocultural standards for personal independence and social responsibility (e.g., communication, social participation, independent living); and 3) onset of intellectual and adaptive deficits during the developmental period (childhood and adolescence; many consider 18 years of age the cut off point, although not specified in the DSM-5).

Cases of Intellectual Disability are classified on the basis of the severity of intellectual impairment, but this classification is no longer dependent upon an IQ score in DSM-5. Mild Intellectual Disability, which accounts for 85 percent of all Intellectual Disability cases, may not become apparent until a child is of school age and has difficulty meeting educational demands. Moderate Intellectual Disability occurs in approximately 10 percent of individuals with Intellectual Disability.  These individuals usually develop communication skills during early childhood, slightly later than those with Mild Intellectual Disability, who generally acquire both communication and social skills during the preschool years. Individuals with Moderate Intellectual Disability can be trained to perform unskilled work under close supervision. Individuals with Severe Intellectual Disability constitute 3 percent to 4 percent of the Intellectually disabled population. In Severe Intellectual Disability, communicative speech usually does not develop during early childhood, although it may be acquired during the school-age years. Individuals with Severe Intellectual Disability can learn basic self-care but need more supervision. Profound Intellectual Disability occurs in approximately 1 percent to 2 percent of people with Intellectual Disability. Communication skills and sensorimotor functioning are significantly impaired. These individuals need nearly constant supervision and generally benefit from a one-to-one relationship with a caregiver.

Although it is difficult to distinguish children with Mild Intellectual Disability from children without Intellectual Disability during infancy, early warning signs may be evident in more severe cases of Intellectual Disability. The most obvious signs include the infant’s lack of an age-appropriate interest in the environment and delays in motor development. Infants with Intellectual Disability may fail to make eye contact while feeding, may be less responsive to voice or movement, and may be less ready to interact with their parents or other stimuli.

When assessing for Intellectual Disability, it is important to note that the WISC-IV has a high floor, or a minimum possible score of about 50 (about three standard deviations below the mean). As a result, this test cannot provide an accurate assessment of the level of Intellectual Disability in someone with this disorder. As with giftedness, for which the Stanford-Binet has a higher ceiling than the Wechsler tests, the Stanford-Binet would be used to assess Intellectual Disability because its floor is much lower.

The causes of Intellectual Disability are varied, and etiology may be undetermined in approximately 30 percent to 40 percent of cases. Clear etiologies are easier to ascertain in individuals with Severe or Profound Intellectual Disability. Prenatal etiologies include genetic syndromes, such as, inborn errors of metabolism, brain malformations, or maternal disease; and environmental influences, such as, alcohol intake or other teretogens during pregnancy. Perinatal causes may relate to labor and delivery events and postnatal causes include hypoxic ischemic injury, traumatic brain injury, infections, seizure disorders and intoxications.

Individuals with Intellectual Disability are up to three to four times more likely than individuals in the general population to experience other mental, neurodevelopmental and medical disorders or physical conditions. Associated comorbid disorders include Attention-Deficit/Hyperactivity Disorder, Mood Disorders, Anxiety Disorders, Autism Spectrum Disorder, Stereotypic Movement Disorder, Impulse-Control disorders and major neurocognitive disorder.

FLASHCARD:
Intellectual Disability (Intellectual Developmental Disorder) requires three criteria
1. Deficits in intellectual functioning, confirmed both by clinical assessment and individualized, standardized intelligence testing;
2. Marked deficits in adaptive functioning associated with inability to develop culturally expected standards of personal independence and social responsibility;
3. Onset during developmental period (childhood and adolescence)  (often considered age 18)

Classified on basis of severity of intellectual impairment
1. Mild Intellectual Disability:  accounts for 85 percent of all Intellecutal Disability cases; may not become apparent until a child is of school age and has difficulty meeting educational demands; generally acquire both communication and social skills during the preschool years
2. Moderate Intellectual Disability: approximately 10 percent of individuals affected; usually develop communication skills during early childhood; can be trained to perform unskilled work under close supervision
3. Severe Intellectual Disability: 3 to 4 percent of the affected population; communicative speech usually does not develop during early childhood, although it may be acquired during the school-age years; can learn basic self-care, but need more supervision
4. Profound Intellectual Disability: approximately 1 to 2 percent of individuals affected; communication skills and sensorimotor functioning are significantly impaired; need nearly constant supervision and generally benefit from a one-to-one relationship with a caregiver

Early warning signs
May be evident in more severe cases of Intellectual Disability: infant’s lack of age-appropriate interest in environment and delays in motor development; failure to make eye contact during feeding; may be less responsive to voice or movement; and may be less ready to interact with their parents or other stimuli

Assessing Intellectual Disability
1. WISC-IV has a high floor, or a minimum possible score of about 50 (about three standard deviations below the mean); this test cannot provide an accurate assessment of lower IQ scores.
2. Stanford-Binet: best to assess Intellectual Disability because its floor is much lower (also to assess giftedness)

Causes of Intellectual Disability
1. Varied and etiology may be undetermined in approximately 30 percent to 40 percent of cases
2. Clear etiologies: easier to ascertain with Severe or Profound Intellectual Disability
3. Most common identifiable cause: Prenatal etiologies include genetic syndromes, such as, inborn errors of metabolism, brain malformations, or maternal disease; and environmental influences, such as, alcohol intake or other teretogens during pregnancy. Perinatal causes may relate to labor and delivery events and postnatal causes include hypoxic ischemic injury, traumatic brain injury, infections, seizure disorders and intoxications.

Individuals with Intellectual Disability
1. Up to three to four times more likely to experience other mental, neurodevlopmental and medical disorders or physical conditions.
2. Associated comorbid disorders: Attention-Deficit/Hyperactivity Disorder, Mood Disorders, Pervasive Developmental Disorders, Stereotypic Movement Disorder, Impulse-Control Disorder, and Major Neurocognitive Disorder.

QUESTION:
A diagnosis of Intellectual Disability requires deficits in intellectual functioning and:

ANSWERS:
A. impairment in communication skills.
B. delayed motor development.
C. deficits in adaptive functioning.
D. patterns of stereotypic movement.

RATIONALE: Answer C is correct. A diagnosis of Intellectual Disability requires that three criteria be met: 1) deficits in intellectual functions, 2) deficits in adaptive functioning and 3) onset of deficits during the developmental period. Problems in adaptive functioning may limit communication skills (A), but this is not on the DSM-5 criteria for diagnosing. Motor delays (B) is not related to the diagnostic criteria for intellectual disability. Patterns of stereotypic movement (D) would be more related to autism spectrum disorder, often comorbid with intellectual disability.