Autism Spectrum Disorder (ASD) - Diagnostic criteria, Etiology, Prevalence, and Intervention Strategies

1Diagnostic Criteria for Autism Spectrum Disorder (ASD)

• Core characteristics of ASD:

  • Persistent deficits in social communication and interaction across multiple contexts.

  • Restricted, repetitive patterns of behavior, interests, or activities.

  • Difficulties in the social use of verbal and nonverbal communication.

Deficits in Social Communication and Interaction

• Manifestations:

  • Difficulty developing, maintaining, and understanding relationships.

  • Difficulty using nonverbal communication for social interaction.

  • Difficulty engaging in social reciprocity.

Repetitive and/or Restrictive Behaviors

• Examples:

  • Repetitive motor movements, use of objects, or speech.

  • Insistence on sameness, routines, and ritualized patterns of behavior.

  • Restricted interests that are abnormal in intensity or focus.

  • Over or under-sensitivity to sensory input or unusual interests in sensory aspects of the environment.

Difficulties in Social Use of Verbal and Non-Verbal Communication

• Examples:

  • Deficits in social communication, such as greeting others and sharing information appropriately.

  • Difficulties understanding ambiguous meanings of language (e.g., humor).

  • Difficulties following rules for conversation.

  • Difficulties understanding what is not explicitly stated.

Venn Diagram Representation

• Social deficits, language impairment, and repetitive behaviors are central to autism symptoms.

• These core symptoms overlap with associated neurological issues, systemic issues, and related disorders.

Etiology (Causes)

• Genetic Link:

  • Parents with one child with ASD have a $5\%$ chance of having another child with ASD.

  • In twins, if one child has ASD, there is a $90\%$ chance the other twin has ASD.

• Environmental Link:

  • Toxins, maternal age, maternal nutrition, maternal infection.

• Risk Factors:

  • Sex, family history, preterm infants, parental age.

• No single cause identified.

• Important Note: NO LINK TO VACCINATIONS.

Prevalence

• The CDC estimates that 1 in 31 children have ASD.

• Males are 4x more likely to have ASD than females.

• The continued increase is attributed to changes in diagnostic criteria and early detection.

Physical/Movement Characteristics

• Motor milestone delays.

• Hypotonia (decreased muscle tone).

• Motor processing issues; sensory processing issues.

• Fine motor delays.

• Motor apraxia - characterized by the inability to plan and execute purposeful movements.

Implications for Physical Activity

• Activity selection should be based on the person’s needs and interests.

• Individual and small-group activities are preferred over competitive team sports.

• Use an affinity-based approach: leverage the person’s special interests to promote active participation.

• Individuals may not initiate participation.

• They may be distractible due to high arousal, anxiety, and hyperactivity.

• Poorly developed movement skills and motor processing issues are common.

Instructional Strategies

• Start with "closed" skills - provide extra time to practice and process.

• Limit "open" skills – skills that require quick decision-making and adaptation.

• Reduce excess noise and distractions that can overload sensory input.

• Involve choice-making and goal setting.

• Use rewards with preferred activities.