Autism Spectrum Disorder

Description and Etiology of Autism Spectrum Disorder

• ASD is a disorder characterized by social communication deficits, restricted and repetitive behaviors, and unique strengths.
• The prevalence of ASD varies by gender, ethnicity, and socioeconomic status.
• Early deficits in social cognition typically shown by infants and toddlers who are later diagnosed with ASD include:
  • Social-emotional reciprocity deficits
  • Nonverbal communication deficits
  • Deficits in interpersonal relationships
• Restricted, repetitive behaviors, interests, or activities include:
  • Stereotyped or repetitive behavior
  • Excessive adherence to routines
  • Fixated interests
  • Unusual sensitivity to sensory input
• Comorbid disorders with ASD include:
  • Intellectual disability
  • Communication disorders

Epidemiology of Autism Spectrum Disorder

• Boys are more likely to be diagnosed with ASD than girls.
• Boys have higher IQ scores than girls with ASD.
• Boys have more profound deficits in IQ than girls with ASD.
• Girls have more social communication problems and sleep and mood problems than boys with ASD.
• Girls have better social linguistic functioning than boys with ASD.
• Hormone differences may contribute to the prevalence of ASD in boys.

Causes and Delays in Social Cognition

• Genetic and environmental factors contribute to ASD.
• The heritability of ASD is high.
• Advanced parental age and grandparental age are associated with an increased risk of ASD.
• Abnormalities in brain structure and functioning, including:
  • Social brain
  • Synaptic density and neural connections
  • Head circumference and brain density
  • Growth dysregulation hypothesis
• Three brain regions implicated in ASD:
  • Amygdala (social and emotional functioning)
  • Fusiform gyrus (face processing)
  • Prefrontal cortex (executive function)

Identification, Prevention, and Treatment

• Early signs of ASD include:
  • Social-emotional reciprocity deficits
  • Nonverbal communication deficits
  • Deficits in interpersonal relationships
• Routine screening is recommended for early diagnosis.
• Applied Behavior Analysis (ABA) is an evidence-based approach to treat ASD.
• Pivotal Response Treatment (PRT) addresses motivation and self-regulation.
• TEACCH is a comprehensive program for youth with ASD.
• The Developmental Social-Pragmatic Model focuses on social communication skills.
• The Early Start Denver Model (ESDM) combines two approaches to treat ASD.
• Augmentative and Alternative Communication (AAC) compensates for language deficits.
• Speech-Generating Devices (SGDs) provide new options for communication.
• Medications are used to treat ASD.
• Interventions with limited scientific support should be avoided.