Timing of the Diagnoses of Attention Deficit Hyperactivity Disorder and Autism Spectrum Disorder in Taiwan.

Wei et al. (2021) looked at medical records in Taiwan. They wanted to know if getting an ADHD label first changes when a child hears "autism."

The team compared kids who had only autism with kids who got an ADHD diagnosis first. They checked how many in each group were older than six when autism was finally spotted.

Children who carried an ADHD tag first were almost 11 times more likely to learn about their autism after age six. The extra wait did not happen when autism was noticed first.

In plain words, the ADHD label pushed the autism discovery back by years.

Green et al. (2015) already showed that elementary students with ADHD score higher on autism symptom checklists. Han-Ting now adds the timing piece: those same symptom elevations are being missed for years.

Reus et al. (2013) found that parent interviews inflate autism severity when ADHD is also present. The Taiwan data say this inflation may hide the need for an autism evaluation until the child is well into grade school.

Noterdaeme et al. (2010) and Shrestha et al. (2014) described long waits for autism diagnosis in Germany and Nepal. Han-Ting narrows the problem, pointing to one clear driver—an earlier ADHD diagnosis—that teams can act on.

If a child on your caseload has ADHD, do not wait for "obvious" autism red flags. Run an autism screener like the SCQ at intake and re-check every six months. Catching both labels sooner lets you write goals that target social, executive-function, and attention needs together instead of playing catch-up later.