Neurodevelopmental Disorders

when do most neurodevelopmental disorders develop

early childhood (before they start school)

3 requirements for intellectual disability

1- deficits in intellectual functioning via an eval (2 or more SD below the mean)

2- deficits in adaptive functioning
3- onset of deficits during developmental period

intellectual disability specifiers

based on adaptive functioning

includes: mild, moderate, severe, profound

stats on causes of intellectual disability

cause is known in 25-50% of cases.

of those that are known:

• 80-85% prenatal factors (e.g., genetic causes. usually down syndrome [most common] and fragile X [second most common]) *note that down syndrome is a chromosome-related genetic disorder but fragile X is the most common inherited genetic disorder

• 5-10% perinatal (e.g., asphyxiatia)

• 5-10% postnatal

when is prognosis best for ASD (3 factors)

• IQ over 70

• functional language by age 5

• absence of comorbid mental health problems

study on ASD face and emotion recognition

children w/out ASD:

• reacted different to novel and familiar faces and objects

children w/ ASD:

• reacted different to novel and familiar objects

• reacted SIMILAR to novel and familiar faces

• trouble recognizing basic + complex emotions in 3 forms of expression (face, voice, body)

rates of ASD in the US and other countries

• global: 1%

• US:

  • children under 8 = 3.2% (1 in 31)

  • 18+ = 2.2% (1 in 45)

diagnosed 3X more often in males than females

causes of ASD (results of twin studies)

cause is both hereditary and environmental (e.g., birth before 26 weeks gestation, exposure to certain drugs or teratogens such as valproic acid, during prenatal development, and advanced parental age).

• twin studies:

  • concordance (both having it) = 59-84% for monozygotic VS 3.5-29% for dizygotic

  • heritability estimate = 62%

brain studies on ASD

Found:

• accelerated brain growth by ~6 months of age then plateaus by preschool years (corresponds to a larger-than-normal head circumference and increased brain volume and weight during that period)

• abnormalities in cerebellum, corpus callosum, and amygdala

• lower-than-normal levels of serotonin in several areas of the brain but elevated levels of serotonin in the blood

goals of behavioral treatment of ASD

minimize symptoms, maximize independence, reduce behaviors that interfere with functional skills

treatments for ASD

• early intensive behavioral intervention (EIBI): evidence-based treatment that uses ABA (40 hours/week of behavioral interventions including shaping and discriminating training for nonspeaking children to communicate verbally).

  • greatest impact on intelligence and language but smaller/less consistent impact on adaptive skills, social functioning, and severity of symptoms

  • no medications have been found effective for the core symptoms of ASDH but sometimes methylphenidate and other psychostimulants are used to alleviate the executive functioning symptoms, SRRIs to treat mood/anx, atypical antipsychotics (usually riseridone and aripiprazole) to reduce irritability and aggressive, self-injurious, or disruptive behaviors

types of neurodevelopmental disorders

ASD, ADHD, tic disorders, communication disorders, SLDs