Early ASD Identification & Intervention

Overview

This review examines early identification, assessment, and treatment of young children (0-5 years) with Autism Spectrum Disorders (ASDs), diagnosed in approximately 1 out of 150 U.S. children. Evidence indicates most ASD cases have onset during the second year of life, making early detection and intervention critical for improving long-term outcomes.

Diagnostic Criteria and Classification

• ASD encompasses previously termed Pervasive Developmental Disorders (PDDs) including autistic disorder (AD), Asperger's disorder, and PDD-NOS
• Primary impairments affect social interaction, communication, and exhibit stereotyped behaviors with restricted interests
• Diagnosis before age 3 shows lower stability (50% PDD-NOS overdiagnosis, 22% underdiagnosis); stability improves significantly by age 4 (80-88%)
• DSM-IV criteria focus on three core domains but lack specific developmental guidelines for young children

Early Signs and Symptoms

• Parents typically first notice concerns between 18-24 months, most commonly regarding speech and language delays
• 10-50% of parents report regression in language and/or social-emotional relatedness during second year of life
• Additional concerns include extreme sensory reactivity, sleep/eating disturbances, and motor development delays

Behavioral Indicators at 12-18 Months:

• Reduced or unusual eye contact and social smiling
• Limited/delayed orienting to name being called
• Deficits in imitation and reciprocal social games
• Delayed language comprehension, production, and gesturing
• Atypical visual tracking and prolonged object fixation
• Decreased activity levels and delayed fine/gross motor skills

Distinguishing Features:

• Atypical word repetition (echolalia) with same intonation as speaker (questioning vs. emphatic tone)
• Unusual screeching, crying, or non-word utterances
• Repetitive movements with or without objects
• Visual inspection of objects at unusual angles or for prolonged periods
• Absence of typical social development markers (more significant than presence of atypical behaviors)

Screening and Early Detection

• American Academy of Pediatrics recommends routine ASD screening at 18 and 24 months during well-child visits
• Screening approaches use two levels: general population screening (Level 1) and targeted screening for at-risk children (Level 2)

Level 1 Screening Tools:

• Checklist for Autism in Toddlers (CHAT): 38% sensitivity at 18 months using less-stringent criteria
• Modified Checklist for Autism in Toddlers (M-CHAT): 85% detection rate; includes parent questionnaire and follow-up interview for 18-30 months
• Pervasive Developmental Disorders Screening Test-II (PDDST-II): surveys nonverbal communication, temperament, sensory responses, play, attachment; no published sensitivity/specificity data
• First Year Inventory: 63-item parent report for 12-month-olds assessing social/communicative and sensory/regulatory behaviors

Level 2 Screening Tools:

• Screening Tool for Autism in Two-Year-Olds (STAT): direct play-based assessment with high specificity, sensitivity, and predictive validity
• Communication and Symbolic Behavior Scales Developmental Profile (CSBS DP): includes 13 "red flag" items distinguishing ASD from other developmental disabilities

Best Practice Recommendations:

• Use broader first-stage screeners targeting language/developmental functioning and social-emotional/behavioral problems
• Follow positive screens with Level 2 assessment or referral to comprehensive evaluation
• Maintain clinical conversation with parents to determine appropriate next steps

Diagnostic Assessment

Gold Standard Tools:

• Autism Diagnostic Observational Schedule (ADOS): semistructured assessment of communication, social interaction, and play; four modules based on developmental/language level
• ADOS performs best with nonverbal mental age ≥15 months; excellent sensitivity but decreased specificity in younger children
• ADOS-Toddler Module (ADOS-T): for children 12+ months; indicates ranges of concern rather than diagnostic categories
• Autism Diagnostic Interview-Revised (ADI-R): standardized caregiver interview; modified administration for children under 4 years (excludes certain imaginative play items)

Comprehensive Assessment Requirements:

• Detailed developmental history across settings and caregivers
• Standardized assessments of language, communication, intellectual functioning, and adaptive functioning
• Evaluation of co-occurring conditions: social-emotional problems (anxiety), behavioral issues (aggression), regulatory problems (sleep, eating)
• Assessment must identify both diagnosis and child's strengths/weaknesses to inform treatment planning

Research Tools:

• Autism Observational Scale for Infants (AOSI): semistructured play-based assessment for high-risk infants; evaluates visual, social, communication, motor, and affective domains

Family Context and Adaptation

Parenting Stress Factors:

• Parents of young ASD children report elevated stress and depressive symptoms compared to parents of typically developing or developmentally delayed children
• Stress particularly high during diagnostic uncertainty period with long waiting lists and unclear presentations
• Maternal stress relates to child regulatory problems; paternal stress relates to child externalizing behaviors
• Mothers generally report more stress than fathers

Family Challenges:

• Grief over loss of expected life trajectory for child and family
• Coordinating, advocating for, and making treatment decisions with limited evidence base
• Financial strain from reduced work hours or stopping employment to manage appointments
• Redirection of career expectations and personal identity
• Managing inconsistent child symptom presentations across settings, people, and time

Child Behavior Impact:

• Lack of reciprocity to parents increases stress
• Disruptive or embarrassing public behaviors restrict family activities and social interactions
• Severity of social/communication deficits, sensory sensitivities, and behavioral difficulties exacerbate parenting stress

Protective Factors:

• Effective coping strategies and informal social support
• Positive beliefs about intervention impacts
• Increased parent confidence and self-efficacy through learning intervention techniques
• Maternal acceptance of diagnosis and sense of resolution improves interaction style
• Parent-child relationship quality associates with language gains

Systems Perspective:

• Maternal stress predicted by child behavioral symptoms and partner's depressive symptoms
• Paternal stress predicted by maternal depressive symptoms
• Family members affect one another; comprehensive family assessment needed

Interventions for Young Children

General Principles:

• Interventions must be individualized to child's developmental and learning characteristics
• Early intervention improves long-term communication and adaptive outcomes
• For 12-24 month-olds: prioritize caregiver interactions, nonverbal communication, gestures, joint attention, exploration, imitation, and play skills
• Limited empirical evidence for children under 2 years; families may access speech-language therapy and other early intervention services

Home-Based Interventions:

• Applied Behavior Analysis (ABA): systemic teaching of new skills, reinforcement, imitation, discrimination learning, control of maladaptive behaviors; supported by substantial research
• Pivotal Response Training: naturalistic ABA approach where parents teach skills during daily routines; focuses on multiple-cue responding, initiating behaviors, responding to prompts
• Floortime: developmentally based intervention facilitating social communication; limited systematic study but case reports show language improvements

School-Based Programs:

• Treatment and Education of Autistic and Related Communication Handicapped Children (TEACCH): structured teaching emphasizing visual spatial understanding, object manipulation, incidental communication teaching; parent-delivered version effective for cognition and nonverbal perception
• Denver Model/Early Start Denver Model: developmental approach emphasizing play skills, positive affect, interpersonal relationships, language development; integrates behavioral teaching, language therapy, occupational therapy; targets 14 months-3 years; children show significant gains in symbolic play and language regardless of symptom severity

Skill-Specific Interventions:

• Joint Attention (JA) intervention: effective for initiating and responding to joint attention but not symbolic play
• Picture Exchange Communication System (PECS): teaches requesting through picture exchange; facilitates generalized requests in children with limited initiating joint attention
• Responsive Education and Prelinguistic Milieu Teaching (RPMT): teaches object exchange for turn-taking; facilitates turn-taking and initiating joint attention in children with some existing skills

Research Needs:

• Determine which interventions work best for specific children and families
• Address questions about treatment intensity, settings, caregiver integration, and different approaches
• Identify critical outcome variables and individual response patterns
• Balance parent co-therapist benefits (increased confidence, self-efficacy) with potential role-demand stress

Key Terms and Definitions

• Autism Spectrum Disorders (ASDs): Diagnostic category encompassing pervasive developmental disorders characterized by severe impairments in reciprocal social interaction and communication plus stereotyped behaviors and restricted interests
• Autistic Disorder (AD): Meets full DSM-IV criteria across all three symptom domains (social interaction, communication, repetitive behaviors)
• PDD-NOS: Assigned when marked impairments present but full AD criteria not met; less diagnostic stability than AD before age 3
• Joint Attention: Ability to coordinate attention between people and objects; includes following gaze/point, pointing to show objects, integrating gaze with vocalizations
• Echolalia: Repetition of words or phrases with same intonation as speaker; atypical when questioning tone preserved rather than declarative
• Sensitivity: Proportion of true cases correctly identified by screening tool
• Specificity: Proportion of non-cases correctly identified as negative by screening tool
• Mental Age: Level of cognitive functioning relative to chronological age; important for determining expected developmental behaviors
• Regression: Significant loss of previously acquired language and/or social-emotional relatedness, typically in second year of life
• Macrocephaly: Abnormally large head circumference; early increase evident in some children with autism during first year

Research Findings and Future Directions

• Prospective infant sibling studies reveal first-degree relative recurrence risk of 5-10%
• No consistent ASD markers identified before 12 months of age
• Heterogeneity in symptom presentation, severity, onset, course, and co-occurring conditions requires individualized assessment and treatment
• Early home videotapes show 80-93% of children later diagnosed with ASD evidence social/communication signs at first birthday
• Dismantling studies needed to illuminate intervention components most efficacious for specific populations
• Critical need for research informing treatment tailoring to individual children given heterogeneous presentation
• Improved long-term functioning through earlier detection and intervention represents promising direction for field