Co-occurring conditions sometimes leads to a change in ASD diagnosis

Certain characteristics of autism spectrum disorder (ASD) may change as a child ages. An analysis of a national survey of children’s health found that children with a current diagnosis of ASD were more likely to have a co-occurring neurodevelopmental or psychiatric condition, such as learning disability or depression, than those with a past (but not current) diagnosis of ASD.

Investigators used the 2007 dataset from the US National Survey of Children’s Health to explore how co-occurring conditions differentiate children with a current diagnosis of ASD from those who were diagnosed with ASD in the past but no longer met the criteria for an ASD diagnosis.

The type of co-occurring condition depended on the age of the child:

Three- to 5-year-olds were more than 11 times likely to have ASD with moderate or severe learning disability or developmental delay compared with children with a past but not current ASD diagnosis. The presence of 2 or more co-occurring conditions in this age group was 5 times more likely with a current diagnosis of ASD versus a past but not current diagnosis.

Children 6 to 11 years old were almost 4 times as likely to have had a past speech problem and more than 3 times as likely to have current anxiety. Hearing problems, however, were significantly less common among children in this age group with a current diagnosis of ASD.

Children aged 12 to 17 years with a current ASD diagnosis had almost 4 times the odds of current speech problems and 10 times greater odds of seizures or epilepsy. Adolescents with current ASD were almost 3 times as likely to have 2 or more co-occurring conditions than children with a past but not current ASD diagnosis.

The researchers suggest that the natural history of co-occurring conditions may explain their increased likelihood that they’re diagnosed in conjunction with current ASD.

For example, anxiety tends to become more pronounced with age as children become accustomed to rigid schedules and fear change, and the onset of epilepsy peaks during early adolescence.

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