New research links where children live with autism and ADHD symptoms

Children with autism spectrum disorder (ASD) who are born into ‘underserved’ communities are more likely to have attention-deficit/hyperactivity disorder (ADHD) symptoms than those born in communities with more resources, researchers from the UC Davis MIND Institute have found.  

 

This is the first time researchers have investigated how neighbourhood factors are associated with ADHD in autistic and non-autistic children, with the study providing new insights into mental health conditions. 

 

“We found that some neighbourhood factors are strongly related to ADHD symptoms in autistic children,” first author Professor Catrina Calub said.

 

“In this study, we didn’t find this effect in typically developing kids (sic.) or in kids with other developmental disabilities, only in the autistic children. It suggests that when autistic kids live in neighbourhoods with fewer resources, they tend to have more pronounced ADHD symptoms,” she added.

 

ADHD symptoms can include higher rates of inattention, hyperactivity and impulsive behaviour and are often associated with:

 

• Challenges in school performance and relationships with friends
• Lower self-esteem and greater risk for anxiety and depression
• Higher potential for substance use disorders and accidents
• Emotional dysregulation and conduct problems

 

The researchers used data from two studies: the decades-long Childhood Autism Risks from Genetics and the Environment (CHARGE) study led by Irva Hertz-Picciotto at the MIND Institute and the ReCHARGE follow-up project.

 

CHARGE and ReCHARGE assess how genetics, environment and other factors affect development from early childhood (2– 5 years of age) through adolescence (8-20 years of age).  

 

The team looked at 246 autistic children, 85 with developmental delays (without autism), and 193 who were neurotypical. Then, they applied the Child Opportunity Index, which uses census data to track over 30 neighbourhood traits. These traits include socioeconomics, green space, single-parent households and concentration of early childhood education centers.

 

The index encompasses three domains: education, health and environment, and social and economic resources. Higher scores are linked to better childhood health. Of the three domains, the education and social and economic resources scores were most strongly related to ADHD symptoms.

 

The analysis showed the Child Opportunity Index scores at birth were a strong predictor for ADHD symptoms in adolescence in the autistic children but not in the other groups, a finding which Professor Calub said was unexpected.

 

“These results are quite concerning,” she said candidly. “Those with both autism and ADHD are already more likely to have additional challenges — behaviourally, cognitively, emotionally and socially. Being born in a low-income neighbourhood puts them at an even greater disadvantage. This just adds to the evidence that more resources are needed for underserved areas and specifically for those who have conditions like autism.”

 

“ADHD is highly prevalent in the general population and is common in autistic youth. If we can find ways to increase resources in these neighbourhoods, we have the potential to improve academic, social, mental and physical health outcomes, particularly for autistic youth, and also decrease long-term economic costs.”

 

She would like to see more research to determine if the results would apply to a larger group.

 

“It will be important for future studies to be larger and more diverse. That should help us learn whether neighbourhood conditions might also influence ADHD symptoms in other groups such as youth without autism, or in Black, Asian and Native American individuals, who were under-represented in our sample,” she continued.

 

Read the full study here.