Assessment & Research

Comorbidity rates of autism spectrum disorder and functional neurological disorders: A systematic review, meta-analysis of proportions and qualitative synthesis.

Vickers et al. (2025) · Autism : the international journal of research and practice 2025
★ The Verdict

Expect functional neurological disorders in about one in ten autistic kids with seizures—screen early to cut needless medical workups.

✓ Read this if BCBAs who assess or treat autistic children in medical or school settings.
✗ Skip if Practitioners working solely with adult neurological rehab or single-diagnosis ADHD caseloads.

01Research in Context

01

What this study did

The team pulled every paper on kids who have both autism and functional neurological disorders. These are problems like seizures or tremors that show no clear medical cause.

They counted how often the two conditions travel together. They also looked at the quality of each study to see which numbers we can trust.

02

What they found

About one in ten children with functional seizures also meet criteria for autism. That rate is higher than you would expect by chance.

The same pattern showed up across other functional disorders, not just seizures. The authors say early autism screening could spare families extra tests and worry.

03

How this fits with other research

Rosello et al. (2022) and Casseus (2022) found that autism plus ADHD is also common and brings extra cognitive and behavioral load. The new review extends that line by showing functional seizures are another red-flag pair.

Sorenson Duncan et al. (2021) looked at autism and borderline personality disorder. They concluded the two rarely co-occur above base rates. Fradet et al. (2025) now show the opposite is true for functional neurological disorders, so the field is not seeing blanket comorbidity; it is condition-specific.

Caçola et al. (2017) separated autism from developmental coordination disorder. Their message—do not blame every motor quirk on autism—fits neatly here. Some “mystery” movements may be functional neurological signs that deserve their own care plan.

04

Why it matters

When a child with autism presents with shaking, limping, or non-epileptic seizures, think FND first instead of ordering another MRI. Add a quick autism screener to your intake for any young patient already diagnosed with functional seizures. Catching both labels early lets you craft behavior plans that account for possible stress-related triggers and avoid unnecessary medication.

Free CEUs

Want CEUs on This Topic?

The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.

Join Free →
→ Action — try this Monday

Add the SCQ or another brief autism tool to your intake packet for any child referred for functional seizures.

02At a glance

Intervention
not applicable
Design
systematic review
Population
autism spectrum disorder, mixed clinical
Finding
not reported

03Original abstract

Autism spectrum disorder (ASD) and functional neurological disorders (FND) are relatively common conditions, and there has been recent interest in the overlap between them. Both conditions share core features of alexithymia, impaired interoception and deficits in attentional focus. To date, relatively little is known about the comorbidity rates between ASD and FND. This is the first meta-analysis and qualitative synthesis on the subject. We found that around 10% of children presenting with functional seizures have a comorbid ASD diagnosis. People with ASD are more likely than the neurotypical population to have functional somatic disorders, and there is also evidence that ASD rates are higher for other FNDs such as functional motor disorders. Since FND comes with risks of unnecessary medical procedures and investigations, it is important to recognize the potential for people with ASD to have an FND comorbidity.

Autism : the international journal of research and practice, 2025 · doi:10.1177/13623613241272958