Cortical Gyrification Morphology in ASD and ADHD: Implication for Further Similarities or Disorder-Specific Features?

Area of Science:

• Neurodevelopmental disorders
• Brain morphology
• Cortical development

Background:

• Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) share high comorbidity, phenotypic overlap, and genetic susceptibility, suggesting common etiological pathways.
• Cortical gyrification expansion peaks during early development, coinciding with the emergence of ASD and ADHD symptoms, making it a potential area of investigation for these conditions.

Purpose of the Study:

• To investigate gyrification morphology in children and adolescents with ASD and ADHD compared to typically developing controls.
• To explore the role of gyrification in the etiopathology of ASD and ADHD.
• To examine the effects of IQ and functional implications of gyrification on ASD and ADHD symptomatology.

Main Methods:

• Utilized the local Gyrification Index (lGI) to assess gyrification morphology in 539 children and adolescents (6-17 years).
• Compared individuals with ASD (n=197), ADHD (n=96), and typically developing controls (n=246).
• Employed General Linear Models to analyze group differences, age effects, sex differences, and IQ variability, and explored associations with symptom severity.

Main Results:

• No significant group differences in lGI were found between ASD, ADHD, and control groups.
• An age-related decrease in lGI and higher lGI in females compared to males were observed across all groups.
• No significant associations were found between lGI and social communication deficits, repetitive behaviors, inattention, or adaptive functioning.

Conclusions:

• The study found no evidence of atypical cortical gyrification, as measured by lGI, in children and adolescents with ASD or ADHD.
• Gyrification patterns were influenced by age and sex but did not correlate with specific symptom domains or adaptive functioning in these neurodevelopmental disorders.
• These findings suggest that gyrification differences may not be a primary etiological factor contributing to ASD and ADHD.