Childhood Autism Rating Scale (CARS) and Autism Behavior Checklist (ABC) correspondence and conflicts with DSM-IV criteria in diagnosis of autism.

Connell et al. (2004) compared two checklists used to spot autism.

They looked at the Childhood Autism Rating Scale (CARS) and the Autism Behavior Checklist (ABC).

Both tools were checked against the official DSM-IV rules for autism.

CARS matched the DSM-IV diagnosis every time.

ABC missed almost half of the children who truly had autism.

In short, CARS gave far fewer false negatives.

Udhnani et al. (2025) later warned that any screen, including CARS or ABC, can misread kids who also have ADHD.

Howard et al. (2023) scanned dozens of ABA-linked tests and found weak backing for many; their point echoes here—pick tools with solid data.

La Malfa et al. (2004) ran a similar horse-race that year, showing ABC-C beat DASH-II for tracking change, underlining that checklist choice always matters.

When you screen a new client, start with CARS to lower the chance of a missed diagnosis.

If the child has ADHD traits, remember Manisha’s tip and gather extra data before you decide.

One smart move: keep ABC for other uses, but don’t rely on it alone for the autism label.