What is the correlation between specific scores and the development of Autism Spectrum Disorder (ASD)?

Correlation Between Scores and Development of Autism Spectrum Disorder

Developmental trajectories, rather than single-point measurements, serve as the most reliable risk indicators for Autism Spectrum Disorder (ASD), with atypical patterns in standardized developmental scores between 12-24 months showing the strongest correlation with later ASD diagnosis. 1

Key Developmental Score Patterns Associated with ASD

Early Development (0-12 months)

• No definitive behavioral or diagnostic markers have been consistently identified in infants younger than 12 months 1
• Some studies suggest potential differences between 6-12 months in:
  • Social attention (social gaze, orienting to name) 1
  • Atypical sensory behaviors 1
  • Repetitive or atypical motor behaviors 1
  • Differences in gesture use 1
• Eye-tracking technology has shown diminished orienting to eye regions from 2-6 months in infants later diagnosed with ASD, though these differences lack straightforward behavioral correlates detectable by clinicians or parents 1

Critical Period (12-24 months)

• The strongest correlation appears during the second year of life when:
  • Standard scores on developmental measures begin declining 1
  • Acquisition of new skills noticeably slows 1
  • Previously typical development begins to plateau or regress 1

Specific Score Trajectories

• Longitudinal studies have identified four distinct trajectory clusters in symptom severity scores 2:
  • Non-spectrum (~25%)
  • Worsening (~27%)
  • Moderately-improving (~25%)
  • Severe-persistent (~23%)

Domains of Assessment and Their Correlation with ASD

Research suggests the autism symptom phenotype comprises three primary factors that correlate with diagnosis 3:

1. Social-communication
2. Inflexible language and behavior
3. Repetitive sensory and motor behavior

These domains differ somewhat from the DSM classification but provide a more empirically-derived structure of the ASD phenotype 3.

Developmental Score Patterns by Domain

• Social-communication: May show improvement over time in some children 2
• Restricted and repetitive behaviors: Often remain stable or worsen even when social communication improves 2
• Language and verbal/nonverbal communication: May improve for many children while other symptoms persist 2

Biomarkers and Advanced Assessment Tools

• EEG measurements have shown promise as potential biomarkers, with some studies reporting prediction accuracy exceeding 95% at certain ages, even from measurements taken as early as 3 months 4
• However, no specific biomarkers have been definitively established for clinical diagnosis of ASD 5

Clinical Implications

• Developmental surveillance should be conducted during all well-child visits, with standardized developmental screening at 9,18, and 30 months 6
• When evaluating scores:
  • Focus on trajectories rather than single time-point measurements 1
  • Pay particular attention to plateaus or declines in previously normal development 1
  • Consider domain-specific changes, as they may not align with overall severity score trajectories 2

Common Pitfalls in Score Interpretation

• Relying on single time-point assessments rather than developmental trajectories 1
• Failing to consider that different symptom domains may follow different trajectories 2
• Not accounting for gender differences in presentation, which may affect scoring (females often show less disruptive behaviors) 1
• Overlooking the impact of comorbidities on developmental scores (approximately 75% of ASD patients have comorbid conditions) 7

The most reliable approach to early identification involves regular monitoring of developmental trajectories across multiple domains, with particular attention to changes in social communication, language development, and the emergence of restricted or repetitive behaviors between 12-24 months of age.