lecture 12 Flashcards
Neurodevelopmental Disorders
What are Neurodevelopmental Disorders
Disorders of early brain development including ADHD, Autism Spectrum Disorder, Learning Disorders, and Communication Disorders
What are the ABCDE Characteristics of Attention-Deficit/Hyperactivity Disorder
A) A persistent pattern of inattention and/or hyperactivity that interferes with functioning or development, as characterized by (1) and/or (2):
1) Inattention
2) Hyperactivity and Impulsivity
B) Several inattentive or hyperactive-impulsive sxs were
present prior to age 12
C) Several inattentive or hyperactive-impulsive sxs are
present in 2+ settings
D) Sxs clearly interfere with life functioning
E) Sxs are not better explained by another mental disorder1
What are the differences between characteristics A1 and A2 for ADHD
Both levels must involve 6+ symptoms that have
persisted for at least 6 mos and are inconsistent with
developmental period and significantly impact
social/academic/work functioning
A1) Inattention symptoms:
a. Often fails to give close attention to details or makes careless mistakes
b. Often has difficulty sustaining attention
c. Often does not seem to listen when spoken to directly
d. Often does not follow through on instructions and
fails to finish schoolwork, chores, or duties in the workplace
e. Often has difficulty organising tasks and activities
f. Often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort
g. Often loses things necessary for tasks or activities
h. Is often easily distracted by extraneous stimuli
i. Is often forgetful in daily activities
A2) Hyperactivity and impulsivity: symptoms
a. Often fidgets with or taps hands or feet or squirms in seat
b. Often leaves seat in situations when remaining seated is expected
c. Often runs about or climbs in situations where it is
inappropriate
d. Often unable to play or engage in leisure activities
quietly
e. Often on the go, acts as if driven by a motor
f. Often talks excessively
g. Often blurts out answers before a question has been completed
h. Often has difficulty waiting their turn
i. Often interrupts or intrudes on others
What specifications must be made when characterising ADHD
Specify whether:
* Combined presentation: Both A1 and A2 are met
* Predominantly inattentive presentation: A1 is met, but
not A2
* Predominantly hyperactive/impulsive presentation: A2 is
met, but not A1
What is the prevalence of ADHD
- Occurs in 5% of school-aged children globally
- In general population (including adults), 5 to 11% meet criteria
- ADHD most commonly diagnosed in USA
- prevalence ratio boys:girls = 3:1
- symptoms usually appear around 3-4yrs
- 65-80% continue having symptoms in adolescence
- Half of children with ADHD continue to have symptoms as
adults, but only 15% may continue to have the diagnosis
Why might the diagnosis of ADHD be higher in USA
- Could be the result of children
getting a diagnosis that isn’t warranted due to a limited
assessment - May also be due to some individuals preferring to
diagnosis ADHD rather than oppositional defiant
disorder or conduct disorder
What are the Biological Influences on ADHD
Genetic contributions: Heritability estimates as high as 80%
- most notable gene contributors are those associated with dopamine including DAT1 (dopamine transporter gene) and Dopamine receptors DRD4 and DRD5
- other important genes include Norepinephrine, GABA, and serotonin
Neurobiological correlates of ADHD include:
- smaller brain volume
- inactivity of the frontal cortex and basal ganglia
- abnormal frontal lobe development and functioning
What are the Environmental Influences on ADHD
- role of toxins such as lead intoxication
- food additives (e.g., dyes, pesticides) may play very
small role in hyperactive or impulsive behavior among children - maternal smoking increases risk
- Family factors including parent-child relationships which interact with neurobiological factors to influence symptom expression
- Parents of kids with ADHD give more commands and
have more negative interactions with their kids
What are the treatment options for ADHD
Goal of biological treatments: reduce impulsivity and
hyperactivity, improve attention
- Stimulant medications (methylphenidate) - e.g. Ritalin, Dexedrine, Adderall
- Drugs appear to work by interacting with the dopamine
system - 80% of children with ADHD are prescribed stimulants
- drugs are better than placebo and other active treatments (SHORT TERM)
- Behavioral treatment for children
- Reinforcement programs increase appropriate behaviors, decrease inappropriate behaviors
- May also involve parent training
- In Adults: Cognitive behavioral therapy to increase attention and organization
- Combined bio-psycho-social treatments: May be superior to medication or behavioral treatments alone in the short-term—more research needed
What disorders does the label “Autism Spectrum Disorder” encompass
- Autistic disorder
- Asperger’s disorder
- Childhood disintegrative disorder
- Rett syndrome
What are the ABCDE Characteristics of Autism Spectrum Disorder
A) Persistent deficits in social communication and social
interaction across multiple contexts, as manifested by:
1. Deficits in social-emotional reciprocity
2. Deficits in nonverbal communicative behaviour used for social interactions
3. Deficits in developing, maintaining, and understanding relationships
B)Restricted, repetitive patterns of behaviour, interests, or activities, as manifested by:
1. Stereotyped or repetitive motor movements, use of
objects, or speech
2. Insistence on sameness, inflexible adherence to
routines, or ritualized patterns of verbal or nonverbal
behavour
3. Highly restricted, fixated interests that are abnormal in
intensity or focus
4. Hyper- or hyporeactivity to sensory input or unusual
interest in sensory aspects of the environment
C) Sxs must be present in the early developmental period
D) Sxs cause clinically significant impairment in important areas of life functioning
E) Sxs are not better explained by another mental disorder—
note—intellectual disabilities often co-occur—to give both dxs social communication should be below that expected for the general developmental level
What specifications need to be made when characterising Autism Spectrum Disorder
Specify current level of severity:
* Level 1— “Requiring support”
* Level 2— “Requiring substantial support”
* Level 3— “Requiring very substantial support”
What is the prevalence of Autism Spectrum Disorder
- 1 in 50-68 school-aged children meet criteria
More commonly diagnosed in males (Gender ratio: 5:1) - 38% show intellectual disabilities
What are the genetic biological influences on Autism Spectrum Disorder
Genetic contributions
* Heritability estimates as high as 80%
* An identical twin has a 47-90% chance of having ASD if
the other twin has ASD
* For non-twin siblings, if one child has ASD, the chance
of having a second child having ASD is 20%
* Even if siblings do not meet criteria for ASD, they will
likely show some deficits in social communication and
interactions
* Numerous genes on several chromosomes involved e.g. deletion on Chromosome 16
What are the neurobiological biological influences on Autism Spectrum Disorder
- Brains become significantly larger between the ages of
two and four than those of nonASD individuals, but not
all individuals with ASD have larger brains - Brain growth appears to slow abnormally in later childhood
- Larger amygdala at ages 3 and 4 related to more social
and communication difficulties at age 6 - Enlarged cerebellum associated with less exploration of surroundings
- Low levels of oxytocin in individuals with ASD which effects bonding and social memory
VACCINATIONS DO NOT INCREASE THE RISK OF AUTISM THIS IS A MISCONCEPTION
