Identifying Unique Versus Shared Pre- and Perinatal Risk Factors for ASD and ADHD Using a Simplex-Multiplex...

Area of Science:

• Neurodevelopmental disorders
• Pediatric psychiatry
• Genetics and epigenetics

Background:

• Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) frequently co-occur, suggesting shared underlying mechanisms.
• Pre- and perinatal risk factors (PPFs) are hypothesized to influence the manifestation of these neurodevelopmental disorders.

Purpose of the Study:

• To investigate shared and unique PPFs for ASD and ADHD.
• To differentiate PPF involvement in single-incidence (SPX) versus multi-incidence (MPX) families.

Main Methods:

• Retrospective parent-report data on PPFs were collected from children in ASD families, ADHD families, and control groups.
• Sample stratification included affected/unaffected offspring and SPX/MPX family structures.

Main Results:

• No shared PPFs were identified for ASD and ADHD, except for large family size and increased firstborns in affected offspring.
• PPFs like maternal infections and suboptimal birth conditions were linked to ASD, while low parental age, maternal diseases, smoking, and stress were associated with ADHD.
• PPFs for ADHD appeared to indicate shared risk, whereas for ASD, they seemed more determinative.

Conclusions:

• The co-morbidity of ASD and ADHD is unlikely due to shared PPFs.
• PPFs may play distinct roles in the developmental pathways of ASD and ADHD.
• Family stratification (SPX/MPX) suggested potential etiological differences in ASD but not ADHD.