Assessment & Research

Do communication and social interaction skills differ across youth diagnosed with autism spectrum disorder, attention-deficit/hyperactivity disorder, or dual diagnosis?

Salley et al. (2015) · Research in autism spectrum disorders 2015
★ The Verdict

ADOS social-communication scores fall on a clear ladder—ASD worst, then ASD+ADHD, then ADHD and typical kids about equal—giving you a fast, objective way to separate the three groups.

✓ Read this if BCBAs doing differential diagnosis for school-age kids who may have ASD, ADHD, or both.
✗ Skip if Practitioners working solely with infants or with genetic syndromes outside the ASD-ADHD overlap.

01Research in Context

01

What this study did

Salley et al. (2015) compared ADOS social-communication scores across four groups of youth: autism spectrum disorder, ADHD, both ASD and ADHD, and no diagnosis.

They used a quasi-experimental design. Each child completed the same ADOS module so scores could line up.

02

What they found

Scores lined up like steps: ASD worst, then ASD+ADHD, then ADHD about equal to typical youth.

The pattern gives clinicians a clear, number-based way to tell the conditions apart.

03

How this fits with other research

Stadnick et al. (2015) extends this work into the real world. Their community clinics got the same clean split, but stress you must watch for other mental-health flags or you risk over-calling ASD.

Perez et al. (2015) looks almost contradictory at first. They found no heart-rate difference between ASD+ADHD and ADHD-only teens. The trick: they measured biology, not behavior. ADOS catches social gaps; cardiac reactivity does not.

Zayat et al. (2011) adds another clue. Kids with ASD alone show a unique downward stair on WISC-IV verbal subtests, unlike ADHD kids. Pair that pattern with high ADOS social scores and your diagnosis gets even safer.

04

Why it matters

If you test a child who is chatty yet scores high on ADOS social reciprocity, pause before you label straight ADHD. Check for the ASD+ADHD stair-step profile. Add a brief cognitive scan for the WISC-IV verbal drop. These free, quick checks cut referral errors and keep treatment plans focused on the right targets.

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Pull up the last three ADOS reports you wrote; check if social-communication totals line up with the stair-step pattern and adjust your risk statements before finalizing.

02At a glance

Intervention
not applicable
Design
quasi experimental
Sample size
209
Population
autism spectrum disorder, adhd, mixed clinical
Finding
positive
Magnitude
medium

03Original abstract

Given the well-documented symptom overlap between Autism Spectrum Disorder (ASD) and Attention Deficit/Hyperactivity Disorder (ADHD), careful evaluation of potential differentiation and overlap is critical for accurate diagnostic decisions. Although research has considered the use of symptom checklists and parent/teacher report questionnaires for symptom differentiation, standardized observational methods, typically utilized in the context of ASD evaluation, have received less attention. The present study examined the continuum of communication and social interaction impairment for youth diagnosed with ASD and ADHD, as indexed by the Autism Diagnostic Observation Schedule (ADOS). Participants were 209 youth ages 3 to 18 years with ASD, ADHD, Dual Diagnosis (ASD+ADHD) or No Diagnosis. Differences across diagnostic groups were observed for mean communication and social interaction total scores on the ADOS, with the highest scores (i.e., greater impairment) observed for the ASD group and lowest scores for the ADHD and No Diagnosis groups. Results provide the first evidence for use of the ADOS for distinguishing youth who have ADHD alone versus ASD alone or co-occurring ASD+ADHD. Findings are discussed in light of implications for clinical practice and future research.

Research in autism spectrum disorders, 2015 · doi:10.1016/j.rasd.2015.08.006