Autism Spectrum Disorder
- Neurodevelopmental disorder characterized by:
- Delays/impairments in development of social communication and social interaction
- Restricted, repetitive patterns of behavior, interests, or activities
- Symptoms present in early childhood
- Significant impairment in functioning
- Diagnostic criteria changes since 2013:
- DSM-IV previously included autistic disorder, Asperger disorder, Rett disorder, childhood disintegrative disorder, and pervasive developmental disorder, not otherwise specified within overall category
- DSM-5 has eliminated these separate diagnoses due to insufficient evidence.
- DSM-5 added severity levels (1 to 3) based on the level of support required.
- Associated with specific known genetic disorder (e.g., fragile X) in a minority (15%) of cases
- Behaviors exist along continuum with unclear boundaries between trait and disorder.
- Approximately 1 in 68 (14.6 per 1,000) of 8 year-old children, according to the Centers for Disease Control and Prevention (CDC) 2016 report
- Rate rising over past decades
- 4 times more common in males than females
- Females are more frequently severely impaired with intellectual disability.
- Strong genetic influence: risk in 1st-degree relatives 2–18%; identical twins 35–95%
- Multiple genes implicated (>100), suggesting polygenic risk. Approximately 15% of children with autism have identifiable genetic anomaly.
- Other risk factors: closer spacing of pregnancies, advanced maternal or paternal age, extreme premature birth (<26 weeks), possible maternal inflammation in utero
- Link to vaccinations not supported by scientific evidence
- Pathophysiology unknown but may be associated with abnormalities in cortical laminar architecture during prenatal brain development
Commonly Associated Conditions
- Intellectual disability
- Gastrointestinal (GI) problems
- Sleep disorders
- Anxiety, depression, mood disturbances
- Aggression and self-injury
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