Children and adolescents with an autism spectrum disorder(ASD) are more likely to have co-occurring conditions such as developmental delay and speech problems, researchers in the US have claimed.

Writing in the journal Pediatrics, researchers at the Johns Hopkins Bloomberg School of Public Health examined the relationship between co-occurring conditions in children with ASD and whether their ASD diagnosis remained stable or changed The study, 'Co-occurring Conditions and Change in Diagnosis in Autism Spectrum Disorders', found that the type and number of co-occurring conditions vary by children's age. These conditions include anxiety, depression, developmental delay, speech problems and seizures. 

"Our study found that children with a current ASD aremore likely to have co-occurring conditions compared to children who no longer have an ASD diagnosis," said Heather Close, the study's lead author. The study analysed data of parent-reported ASD diagnoses from 1,366 children in the National Survey of Children's Health 2007 dataset by three age groups: young children (3-5years); children (6-11 years); and adolescents (12-17 years).

In the survey, parents of children in each age group were asked whether their child had a current ASD diagnosis, or had received the diagnosis in the past but no longer had one. The percentage of children found to have had a change in ASD diagnosis were 25%, 33%, and 35% for young children, children and adolescents, respectively.

Across all age groups, children with a current ASD diagnosis were more likely to have at least 2 co-occurring conditions, compared to children who no longer had the diagnosis. Co-occurring conditions of ASD varied by age. Among the youngest children, those with acurrent ASD diagnosis were more likely to have a moderate/severe developmental delay and moderate/severe learning disability compared to children who no longer had the diagnosis. At ages 6 to11, children with ASD had past speech problems, as well as current moderate/severe anxiety disorders, compared to children who no longer had the diagnosis.

Finally, in the adolescent group, those with ASD were more likely to have current moderate/severe speech problems and current seizures compared to children who no longer had the diagnosis. "Clinicians working with children with ASD need to recognise that certain co-existing conditions of autism differentiate children who continue having the diagnosis from children who no longer have the diagnosis," said senior author Li-Ching Lee, a psychiatric epidemiologist at the Bloomberg School of Public Health. 

"Beside the core symptoms of autism, the clinicians would need to evaluate the child on these conditions." 

The message is the same for parents. "They should have their child evaluated for possible co-existing conditions, in addition to core symptoms of ASD to make sure an ASD diagnosis is properly determined," Lee added. "That way, a more appropriate intervention for the child can be planned as early aspossible."