Can Brain Scans and Behavior Tests Identify New Subgroups of Neurodevelopmental Disorders?

What you need to know

• Researchers combined brain scans and behavioral tests to identify new subgroups that cut across traditional diagnostic categories for autism, ADHD, and OCD.
• Four new subgroups were found that showed more similar brain and behavior profiles within each group compared to the traditional diagnostic categories.
• The new subgroups differed in brain structure, symptoms, and everyday functioning in ways that could potentially inform treatment approaches.

A new approach to understanding neurodevelopmental disorders

Neurodevelopmental disorders like autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and obsessive-compulsive disorder (OCD) are typically diagnosed based on observable symptoms and behaviors. However, there is often significant overlap in symptoms between these disorders, as well as a lot of variation among individuals with the same diagnosis. This can make it challenging to understand the underlying biology and develop targeted treatments.

To address this challenge, researchers are exploring new ways of grouping individuals that go beyond traditional diagnostic categories. In this study, scientists used advanced brain imaging and behavioral assessments to identify new subgroups of children with ASD, ADHD, and OCD that cut across diagnostic boundaries.

Combining brain and behavior data

The study included 176 children aged 6-16 years who had been diagnosed with ASD, ADHD, or OCD. Each child underwent:

• MRI brain scans to measure brain structure
• Behavioral assessments of symptoms related to attention, social skills, repetitive behaviors, and other relevant areas
• Tests of cognitive abilities and everyday functioning skills

The researchers then used a technique called Similarity Network Fusion to integrate all of this brain and behavior data. This allowed them to group children who had the most similar overall profiles, regardless of their official diagnosis.

Four new subgroups identified

The analysis revealed four distinct subgroups of children that cut across the traditional diagnostic categories:

Group 1: Mostly children with OCD, plus some with ASD. This group showed:

• Fewer behavioral symptoms overall
• No major differences in brain structure
• Higher IQ scores
• Better everyday functioning skills

Group 2: Mostly children with ADHD or ASD. This group showed:

• Higher inattention symptoms
• Decreased thickness in certain brain regions involved in social skills, language, and executive function
• Altered brain network connectivity

Group 3: Mix of children with ASD and ADHD. This group showed:

• Higher hyperactivity symptoms
• Increased thickness in certain brain regions
• Younger average age

Group 4: Mostly children with ASD, plus some with ADHD. This group showed:

• More severe symptoms across multiple areas
• Decreased size of certain deep brain structures
• Altered brain network connectivity

Importantly, these new subgroups showed more similar brain and behavioral profiles within each group compared to the traditional diagnostic categories of ASD, ADHD, and OCD.

Why this matters

This study demonstrates that looking at a combination of brain structure and behavior can reveal new patterns that are not captured by our current diagnostic system. The subgroups identified here differed in meaningful ways that could potentially inform treatment:

• Group 1 showed better overall functioning, suggesting they may have a more favorable prognosis or respond differently to interventions.

• Groups 2 and 3 showed opposite patterns of brain structure changes, which could reflect different underlying mechanisms contributing to symptoms. This may call for different treatment approaches.

• Group 4 showed more widespread alterations, indicating they may benefit from more comprehensive interventions targeting multiple areas.

Additionally, some children with the same diagnosis ended up in different subgroups. For example, some children with ASD were in the higher-functioning Group 1, while others were in Group 4 with more severe impairments. This highlights the diversity within diagnostic categories and the potential value of more personalized approaches.

Limitations and next steps

It’s important to note that this was an initial study with a relatively small sample size. The findings will need to be replicated in larger, independent groups of children. Additionally, this study only looked at brain structure at one point in time. Future research tracking brain development over time in these subgroups could provide valuable insights.

The researchers also emphasize that these subgroups are not meant to replace current diagnostic categories. Rather, they offer a complementary way of looking at neurodevelopmental disorders that may enhance our understanding and ultimately lead to more targeted treatments.

Conclusions

• Combining brain imaging and behavioral data can reveal new subgroups of children with neurodevelopmental disorders that cut across traditional diagnostic boundaries.
• These subgroups show more similar brain and behavior profiles within each group compared to conventional diagnostic categories.
• This approach could potentially lead to a more nuanced understanding of neurodevelopmental disorders and more personalized treatment strategies.

While more research is needed, this study opens up exciting possibilities for improving how we classify and treat neurodevelopmental disorders in the future. By looking beyond diagnostic labels to underlying biology and behavior patterns, we may be able to better match individuals with the most effective interventions.