Different manifestations of NDs
- Unusual physical features
- Deficits in language
- Deficits in motor ability
- Patterns of behavior such as hyperactivity, aggressiveness, or stereotypy
Intellectual disability DSM-5 Criteria
- A disorder with onset during the developmental period that includes both intellectual and adaptive functioning deficits in conceptual, social, and practical domains
- The following 3 criteria must be met:
1. Deficits in intellectual functions
2. Deficits in adaptive functioning
3. Onset of intellectual and adaptive deficits during the developmental period
Assessments of intelligence
- Verbal comprehension index
- Working memory index
- Perceptual reasoning index
- Processing speed index
- Visual spatial index
Prevalence of intellectual disability
- 8 per 1,000 across all ages
Two parts in measuring intellectual disability
- IQ tests
- Vineland adaptive behaviour studies (test sensory, motor, and language skills)
Intellectual disability etiology (genetic)
- genetic inheritance
- chromosomal abnormalities
- metabolic disorders
Down Syndrome
- trisomy 21
- intellectual impairment can range from mild to severe
- delayed nonverbal cognitive development, deficits in verbal abilities and auditory short-term memory
- higher risk for alzheimer-type demential
Fragile X Syndrome
- more common in boys than in girls
- in most girls the unaffected X chromosome protects them from developing symptoms
- children with more CGG sequences will have more severe cognitive impairments
- IQ scores vary from moderate to normal
- ADHD symptoms, anxiety, aggression, autistic behaviours (25% of males meet autism criteria)
Intellectual disabilities etiology (prenatal environment)
- drugs (consequences for the child)
- environmental pollutants
- nutrition
Potential results of hazards (FASD)
- When a mother’s alcohol consumption during pregnancy affects the fetus
- effects:
- facial deformities
- intellectual disabilities
- attention problems
- hyperactivity, and more
Maternal Factors (Diseases)
- Rubella:
- deafness, cataracts, heart defects, brain disorders, intellectual disabilities, etc.
- Zika virus can lead to microcephaly
- STIs can damage CNS of fetus; genital herpes, HIV infection, AIDS
- Infections such as influenza may lead to schizophrenia
- maternal infection during first trimester increases the risk x7
Maternal Factors (Maternal Emotional State)
- types of stressors:
- stressful life event
- traumatic stress
- chronic stress
» - childhood/youth:
- ASD & ADHD risk
- difficult or irritable temperament
- internalized & externalized problems
- adulthood:
- risk for schizophrenia & depression
Maternal Stress
- behaviour
- cognition
- circadian rhythm
- HPA-axis (exposure to cortisol reduces hippocampal plasticity)
- autonomic system
What are some impacts of maternal stress on the brain and nervous system?
- reduction of hippocampal plasticity -> learning and memory deficits
- amygdala -> mood disorders
- autonomic underarousal -> conduct problems & psychopathic traits
Maternal stress (1998 ice storm in Quebec)
- High levels of objective stress was linked to lower language abilities
Intellectual disability etiology (environmental causes)
Postnatal psychosocial disadvantage:
- psychological and social deprivation
- malnutrition
Study (roman orphanages):
- Lack of support, space, attachment
Autism Spectrum Disorder (ASD)
- 1943, Leo Kanner first identified autism as a childhood disorder
- innate disorder vs environment (frigid/refrigerator mothers)
ASD prevalence
- 1 per 66 children diagnosed in 2015
ASD diagnostic issues
- in the DSM-5, autism spectrum disorder represents a consolidation of disorders that were once diagnosed separately e.g., autism and asperger’s disorder
- asperger’s disorder:
- typical in the domains of language and cognition
- display odd or eccentric behaviours in social interactions
- hard to readily detect as people may be high functioning
ASD communication impairments
- one of the first signs of language impairment is inconsistent use of early preverbal communications
- use protoimperative (what you need to learn before you communicate) gestures rather than protodeclarative gestures
- about 50% do not generate any useful language skills
- qualitative language impairments:
- pronoun reversals
- echolalia (repeat what they just heard)
- perseverative speech (showing signs of OCD)
- impairments in pragmatics (know what people intend to say e.g. can you look at me?)
DSM-5 diagnostic criteria for ASD (A)
(A) Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history:
1. Deficits in social-emotional reciprocity - abnormal social approach, failure of normal back-and-forth conversation, to reduced sharing of interest, emotions, or affect, to failure to initiate or respond to social interactions
2. Deficits in non-verbal communicative behaviours - poorly integrated verbal and non-verbal communication, to abnormalities in contact and body language or deficits in understandings and use of gesture; to a total lack of facial expressions and non-verbal communication
3. Deficits in developing, maintaining, and understanding relationship - difficulties adjusting behaviour to suit various social contexts, to difficulties in sharing imaginative play or making friends, to absence of interest in peers
DSM-5 diagnostic criteria for ASD (B)
(B) Restricted respective patterns of behaviour, interest, or activities, as manifested by at least two of the following, currently or by history:
1. Stereotyped or respective motor movements, use of objects, or speech (handflipping or ticks)
2. Insistence on sameness - inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behaviours
3. Highly restricted, fixated interest
4. Hypo-or hyperactivity to sensory input (e.g. apparent indifference to pain/temperature)
DSM-5 diagnostic criteria for ASD (C,D,E)
(C) Symptoms must be present in early developmental period
(D) Symptoms cause clinically significant impairments in social, occupational, or other important areas of current functioning
(E) These disturbances are not better explained by an intellectual disability or global developmental delay - ID and ASD frequency co-occur, to make co-morbid diagnosis social communication should be below that expected for general developmental level
ASD scale
Needs some support:
- social communication (full sentences, conversation)
- repetitive/restrictive (difficulty switching activities)
»
Needs very substantial support:
- social communication (few words, rarely interact)
- repetitive/restrictive (extremely resistant to change, interferes with daily life)
