Autism diagnosed later in life could be different form: Study

One is that all people with autism have a similar underlying genetic profile, but some are not diagnosed during their youth because their symptoms might be milder or subtle, and only become more noticeable later on.

The other explanation could be that autism diagnosed during childhood and later on are actually different forms of the condition.

The study published in the journal Nature supports the latter theory.

After comparing the genetic profiles of thousands of people with autism in Denmark and the United States, the researchers determined there were significant genetic differences between those diagnosed earlier or later.

“People diagnosed with autism later in life are genetically more similar to those with attention deficit hyperactivity disorder (ADHD),” Thomas Bourgeron, a study co-author and researcher at France’s Pasteur Institute, told AFP.

Those diagnosed later in life also appear to be more at risk of mental health conditions such as depression, the study said.

People with autism are “very different from one another”, Bourgeron emphasised, calling for each patient to receive care tailored to their particular needs.

Uta Frith, an emeritus professor of cognitive development at University College London, not involved in the study, said she was hopeful that in the future even more subgroups within autism “will come to light, and each will find an appropriate diagnostic label”.

“If there is talk about an ‘autism epidemic’, a ’cause of autism’ or a ‘treatment for autism’, the immediate question must be: which kind of autism?”