Can autism be misdiagnosed as ADHD?
Yes, autism can be misdiagnosed as ADHD, particularly in girls and adults. Research from UC Davis (2025) found that 30% of children initially diagnosed with ADHD were later diagnosed with autism, with delays averaging 3 years (Harvard Health, 2015). Overlapping symptoms like impulsivity and social challenges contribute to diagnostic confusion.
Key facts
- 30% of children with ADHD diagnoses later receive autism diagnoses (UC Davis, 2025).
- Autism diagnoses in girls are often delayed until adulthood due to misdiagnosis as ADHD (Autism Speaks, 2026).
- ADHD and autism co-occur in 40-70% of cases (Child Mind Institute, 2026).
- Adult autism diagnoses increased by 300% from 2010-2026, with many previously misdiagnosed (Psychology Today, 2026).
- Boys are 4x more likely than girls to receive childhood autism diagnoses (Child Mind Institute, 2026).
Why does autism get misdiagnosed as ADHD?
Shared symptoms like difficulty focusing, social challenges, and emotional dysregulation often lead to confusion. The Child Mind Institute (2026) notes that ADHD's hyperactive traits may overshadow autism's social communication deficits, especially in girls who mask symptoms. UC Davis researchers (2025) found autism's restricted interests can mimic ADHD's hyperfocus, while sensory overload may be misattributed to inattention.
Who is most at risk for misdiagnosis?
Women and girls face the highest rates: 80% of autistic women report prior misdiagnoses (Autism Speaks, 2026). The Guardian (2026) found gender diagnosis gaps narrow by age 20 as masking behaviors become unsustainable. Adults seeking ADHD evaluations are 5x more likely to discover undiagnosed autism (Psychology Today, 2026).
How does co-occurring ADHD and autism (AuDHD) complicate diagnosis?
40-70% of autistic individuals meet ADHD criteria (Child Mind Institute, 2026). Medical Xpress (2026) notes overlapping genetic risks, while UC Davis (2025) found autism often emerges before ADHD symptoms. The Telegraph (2026) cautions that diagnostic incentives may exacerbate overlabeling without thorough evaluation.
Frequently asked
Can you have both ADHD and autism?
Yes, 40-70% of autistic people also have ADHD (Child Mind Institute, 2026). This co-occurrence is called AuDHD.
What's the average delay between ADHD and autism diagnoses?
3 years, per Harvard Health (2015), with many cases missed until adulthood (Psychology Today, 2026).
Why are girls more likely to be misdiagnosed?
They often mask symptoms and present with less obvious repetitive behaviors (Child Mind Institute, 2026).
Sources
- 01Why Many Autistic Girls Are Overlooked
- 02People diagnosed with ADHD and autism more recently show lower genetic risk than earlier cases
- 03Your Autism Might Be Misdiagnosed as One of These 6 Disorders
- 04Why more women are being diagnosed with autism later in life
- 05Man Diagnosed with Autism at 42 Felt Like a 'Zombie' After Doctors 'Misdiagnosed and Mismedicated' Him for Years (Exclusive)
- 06Why so many adults are missed, and what a late diagnosis actually changes.
- 07What Is AuDHD?
- 08Autistic girls much less likely to be diagnosed, study says
- 09Autism, ADHD or both? Research offers new insights for clinicians
- 10Is it ADHD—or Autism? - Harvard Health
Related on The Spectrum Brief
Further reading
- The Overlapping Worlds of Autism and ADHD: Why 'AuDHD' Is Changing How We Think About Neurodiversity
- New Studies Explore the Complex Link Between Autism and the Gut Microbiome
- The Overlapping Worlds of Autism and ADHD: What 'AuDHD' Means for Diagnosis and Support
- ADHD and Autism (AuDHD): Co-Occurrence, Shared Features, and Management