ASD symptoms in adults with ADHD: a comparative study using ADOS-2

Area of Science:

• Neurodevelopmental Disorders
• Psychiatry
• Clinical Psychology

Background:

• Attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are distinct neurodevelopmental conditions.
• Comorbid presentation of ADHD and ASD is common, but the nature of overlapping symptoms requires further investigation.
• Understanding symptom overlap is crucial for accurate diagnosis and effective treatment in adults.

Purpose of the Study:

• To investigate the presence and nature of autism spectrum disorder (ASD) symptoms in adults diagnosed with attention-deficit hyperactivity disorder (ADHD).
• To compare ASD symptom presentation in adults with ADHD to that of neurotypical controls.
• To explore potential underlying mechanisms contributing to ASD-like symptoms in adult ADHD.

Main Methods:

• Utilized the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) Module 4 for symptom assessment.
• Administered the Autism Spectrum Quotient, Conners' Adult ADHD Rating Scale, and Wechsler Adult Intelligence Scale.
• Compared symptom scoring patterns between a group of 63 adults with ADHD and 31 neurotypical controls.

Main Results:

• Adults with ADHD exhibited significant autism spectrum disorder (ASD) symptoms compared to controls.
• Symptom analyses suggested two distinct mechanisms underlie ASD symptoms in adult ADHD.
• One mechanism appeared qualitatively similar to core ASD features, while the other was linked to ADHD characteristics.

Conclusions:

• Adults with ADHD demonstrate notable ASD symptoms, even without a clinical ASD diagnosis.
• The findings highlight the complex interplay and potential shared or distinct underlying mechanisms between ADHD and ASD.
• Further research is warranted to differentiate and address these overlapping symptom domains.