A fragmented mind being pieced back together, representing understanding autism.

Decoding Autism: How ADOS-2 Scores and IQ Impact Understanding

Elliot Brynn in Mind & Education August 2025 • 4 min read.

"Exploring the Relationship Between Autism Severity Scores and Cognitive Abilities"

The Autism Diagnostic Observation Schedule (ADOS) is a standardized assessment used to evaluate and diagnose autism spectrum disorder (ASD). It involves observing an individual's social interactions, communication, and behavior to identify patterns indicative of autism. Think of it as a structured playbook an examiner uses to observe and score behaviors.

The ADOS-2, Module 4, is specifically designed for verbally fluent adults. After assessment, the person gets an ADOS-2 score. A high ADOS-2 score typically indicates more pronounced autism-related symptoms, this score doesn’t always tell the whole story. Researchers have been working to understand what these ADOS-2 scores truly mean in relation to other aspects of an individual's abilities, particularly their intellectual abilities and everyday social skills.

A recent study delved into the relationship between ADOS-2 scores and other clinical measures in adult males diagnosed with ASD. This study aimed to determine how well the ADOS-2 Calibrated Severity Scores (CSS) align with standardized assessments of social aptitude and non-social behaviors. By exploring these relationships, the researchers hoped to shed light on the usefulness and limitations of the ADOS-2 CSS in clinical evaluations.

Key Findings: Untangling the Web

A fragmented mind being pieced back together, representing understanding autism.

The study involved 40 adult males with a pre-existing ASD diagnosis. Each participant underwent a comprehensive assessment battery, including the ADOS-2 Module 4, measures of core ASD symptoms, and assessments of co-occurring conditions. Researchers then analyzed the data to identify any significant correlations between the ADOS-2 CSS and other measures.

Here's where it gets interesting. The researchers discovered that the ADOS-2 CSS did not correlate with measures that assessed core social deficits or general psychiatric co-morbidity. In layman's terms, this means that the ADOS-2 score didn't necessarily align with other established ways of measuring social skills or mental health issues common in ASD. However, there was a notable negative correlation between the ADOS-2 CSS and intellectual quotient (IQ). This suggests that individuals with higher ADOS-2 scores (indicating more severe autism symptoms) tended to have lower IQ scores.

To recap the finding are:

ADOS-2 CSS doesn't correlate with measures of core social deficits.
ADOS-2 CSS doesn't align with other established ways of measuring social skills or mental health issues common in ASD.
There was a notable negative correlation between the ADOS-2 CSS and intellectual quotient (IQ).
Individuals with higher ADOS-2 scores (indicating more severe autism symptoms) tended to have lower IQ scores.

This negative correlation raises important questions. Does a lower IQ directly influence the expression of autism-related behaviors observed during the ADOS-2 assessment? Or, conversely, do more pronounced autism symptoms impact cognitive development and measured intelligence? These are complex questions that warrant further investigation. Also of note is that this study looked at adult males. Results may be different in females, or in a younger population.

What This Means for Understanding Autism

The findings provide valuable insights into the complexities of autism assessment. While the ADOS-2 CSS can be a useful tool, it's essential to consider its limitations and interpret scores in the context of an individual's overall cognitive profile. The study highlights the importance of comprehensive evaluations that incorporate multiple measures of social skills, cognitive abilities, and co-occurring conditions.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.1007/s10803-017-3293-z, Alternate LINK

Title: Brief Report: Relationship Between Ados-2, Module 4 Calibrated Severity Scores (Css) And Social And Non-Social Standardized Assessment Measures In Adult Males With Autism Spectrum Disorder (Asd)

Subject: Developmental and Educational Psychology

Journal: Journal of Autism and Developmental Disorders

Publisher: Springer Science and Business Media LLC

Authors: Michael J. Morrier, Opal Y. Ousley, Gabriella A. Caceres-Gamundi, Matthew J. Segall, Joseph F. Cubells, Larry J. Young, Elissar Andari

Published: 2017-09-05

Everything You Need To Know

What is the ADOS-2, and how is it used in the evaluation of autism spectrum disorder?

The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) is a standardized assessment tool used to evaluate and diagnose autism spectrum disorder (ASD). It involves observing an individual's social interactions, communication, and behavior to identify patterns indicative of autism. Module 4 of the ADOS-2 is specifically designed for verbally fluent adults, providing a structured way for examiners to observe and score behaviors relevant to autism diagnosis in this population. It is important to remember that the ADOS-2 provides only one measure of behavior and does not tell the whole story.

What does a high ADOS-2 score indicate, and how does it relate to other measures of social skills and IQ?

A high ADOS-2 score generally suggests more pronounced autism-related symptoms. However, a recent study indicates that the ADOS-2 Calibrated Severity Scores (CSS) doesn't necessarily correlate with other established measures of social aptitude or mental health issues common in ASD. Interestingly, the study found a negative correlation between the ADOS-2 CSS and intellectual quotient (IQ), suggesting that individuals with higher scores (more severe symptoms) tend to have lower IQ scores. This indicates that while ADOS-2 scores are valuable, they should be interpreted alongside other cognitive and adaptive measures.

What is the correlation between ADOS-2 scores and IQ, and what are the potential implications of this relationship?

The study revealed a notable negative correlation between ADOS-2 CSS and IQ. This means that, within the study's sample of adult males with ASD, individuals with higher (worse) ADOS-2 scores tended to have lower IQ scores. However, the study did not explore the reasons behind this correlation. It remains unclear whether a lower IQ directly influences the autism-related behaviors observed during the ADOS-2 assessment, or if more pronounced autism symptoms impact cognitive development and measured intelligence. Further research is needed to understand the nature and direction of this relationship.

Why is it important to consider multiple assessments when evaluating autism, and what other factors should be taken into account besides the ADOS-2 score?

The study's findings highlight the importance of comprehensive evaluations when assessing autism. While the ADOS-2 CSS is a useful tool for evaluating autism-related symptoms, it shouldn't be the sole basis for understanding an individual's abilities and challenges. The results showed that ADOS-2 scores did not align with other established measures of social skills or mental health issues. Comprehensive assessments should incorporate multiple measures of social skills, cognitive abilities (like IQ), and assessments for co-occurring mental health conditions to create a complete profile.

Are the findings about ADOS-2 scores and IQ applicable to all individuals with autism, and what future research is needed to further understand this relationship?

The study specifically focused on adult males diagnosed with ASD. The findings may not be directly generalizable to other populations, such as females or younger individuals with ASD. Future research should investigate whether the relationship between ADOS-2 scores and IQ differs across genders and age groups. Additionally, more research is needed to explore the underlying reasons for the negative correlation observed between ADOS-2 scores and IQ, and whether interventions targeting specific autism-related symptoms can impact cognitive development and measured intelligence.