Pre-linguistic Autism Diagnostic Observation Schedule adapted for older individuals with severe to profound mental retardation: a pilot study.

The team took the baby version of the ADOS and made it work for teens and adults who have severe or profound intellectual disability.

They tested 18 people who lived in a state facility. Two psychologists scored each session to see if they agreed.

The goal was to learn if a score of 15 or higher could flag autism in this group.

Raters agreed 96 % of the time, so the tool is reliable.

Using the 15-point cut-off, the test caught 82 % of true autism cases and correctly ruled out 85 % of non-autism cases.

In plain words, the adapted PL-ADOS works well for non-verbal adults with very low IQ.

Sappok et al. (2013) later tested the regular ADOS in adults with ID and saw the opposite problem: it over-diagnosed autism. The difference is severity. Kazak’s group used the baby version and a higher cut-off, which trimmed false positives.

Sasson et al. (2022) extended the same idea to deaf adults with ID. They also tweaked items and got good accuracy, showing the adapt-and-validate path keeps working.

Gallagher et al. (2003) warned that any sensory or developmental disability delays autism diagnosis. Kazak’s pilot is one of the first to answer that warning with a concrete tool fix.

If you assess adults who don’t speak and have IQs below 40, you now have a brief, play-based tool that gives clear numbers. Use the 15-point cut-off, double-score for reliability, and you can document autism for funding or placement without guessing.