Assessment & Research

IQ, parent- and self-reports of child anxiety and salivary cortisol in a sample of children with autism spectrum disorder.

Varela et al. (2023) · Research in developmental disabilities 2023
★ The Verdict

Parent and child anxiety reports do not match cortisol levels in kids with autism, so use both surveys and spit tests.

✓ Read this if BCBAs working with autistic children in clinic or school settings.
✗ Skip if BCBAs who only serve adults or do not assess anxiety.

01Research in Context

01

What this study did

Varela et al. (2023) worked with the kids who have autism.

They checked each child’s IQ, asked parents and kids about anxiety, and took spit samples for cortisol.

The team wanted to see if IQ and anxiety reports matched the body’s stress hormone.

02

What they found

Higher IQ went hand-in-hand with more parent-reported anxiety.

Yet higher IQ also linked to lower cortisol, the stress hormone.

Parent anxiety ratings did not line up with cortisol levels at all.

03

How this fits with other research

Prigge et al. (2013) showed that adults with mild ID can give spit samples just fine, proving the method works.

Ljubičić et al. (2025) found parents of autistic kids have high evening cortisol, extending the cortisol story from child to caregiver.

Rzepecka et al. (2011) found sleep and anxiety together predict behavior, but they used only parent reports.

Enrique’s work now shows parent reports alone may miss the child’s true stress load, creating an apparent contradiction that is solved by adding cortisol data.

04

Why it matters

When you assess anxiety in a child with autism, do not trust only parent or self-report. Add a quick spit test for cortisol. This gives you a fuller picture and helps you plan better supports.

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→ Action — try this Monday

Add a morning spit sample to your next anxiety screening for an autistic client.

02At a glance

Intervention
not applicable
Design
pre post no control
Population
autism spectrum disorder
Finding
not reported

03Original abstract

This study examined the relation between IQ, parent-reported child anxiety, and salivary cortisol levels in youth with autism spectrum disorder (ASD) with a wide range of intellectual abilities using a prospective design. Results showed that IQ at time 1 (T1) positively predicted parent-reports of child anxiety at time 2 (T2); however, IQ at T1 negatively predicted cortisol levels from saliva samples taken at a research laboratory at T2. Parent reports of child anxiety at T1 and T2 were not associated with cortisol levels at T2. Implications for the assessment of anxiety in youth with ASD are discussed.

Research in developmental disabilities, 2023 · doi:10.1016/j.ridd.2023.104604