Outcome Measures for Core Symptoms of Intellectual Disability: State of the Field.

Thurm et al. (2020) looked at every recent drug or therapy trial for people with intellectual disability. They asked a simple question: did the study use IQ or adaptive scores as the main yardstick of success?

The team read trial reports and conference posters. They noted which tests scientists picked and whether the tests showed change after treatment.

Most trials skip IQ and adaptive scales as end points. When the tests were used, they rarely caught real gains. Floor effects and slow change made scores look flat even when families saw progress.

The review warns that new medicines or teaching methods could look like failures simply because the ruler is too blunt.

Halladay (2025) extends this worry and offers a fix: use Vineland-3 plus person-ability scores instead of old IQ tests. This avoids the floor problem Audrey flagged.

Rieth et al. (2022) field-tested the new 15-minute ICD-11 behavioural indicators. The tool gave reliable diagnoses without long IQ batteries, showing one practical way to move past the limits Audrey described.

Goodwin et al. (2012) catalogued psychopathology scales for ID and also found gaps, hinting that measurement troubles go beyond IQ and adaptive scores.

If you run skill-building programs or track medication effects, pick tools that can actually move. Swap the full WISC for Vineland-3 or try out-of-age forms when standard ones bottom out. Log daily living skills, not just full-scale IQ. Your data will show change sooner and families will see the proof they need.