The Reiss Screen for Maladaptive Behaviour: its reliability and internal consistencies.

The team tested the Reiss Screen, a 36-item checklist for spotting mental health problems in adults with intellectual disability. They gave the form to 64 men and women living in a state institution. Two different staff members rated each resident, and the same raters repeated the form after two weeks.

Inter-rater agreement was strong (r = .80). Test-retest numbers were modest but acceptable (r = .60). Internal consistency was good (α = .85). In plain words, the tool gives similar scores when different staff use it and when the same staff use it again later.

Mazur et al. (1992) had already shown IQ scores stay steady over 2.5 years in the same group, so the Reiss Screen joins a line of reliable adult-ID tools.

Guest et al. (2013) later copied the same design with the French PAS-ADD Checklist and also found solid reliability, proving the approach travels across languages.

Cheves et al. (2026) flips the script: their new OWLS-ID lets adults with ID rate their own distress instead of staff doing it. Both studies end with positive internal-consistency numbers, showing the field has moved from observer forms to self-report without losing quality.

If you work in residential or day programs, you can trust the Reiss Screen to flag mood, anxiety, or behavior issues quickly. It takes 15 minutes and needs no PhD to score. Use it during intake, annual reviews, or when a new behavior pops up. Pair it with the newer OWLS-ID if your clients can self-report; together you get both sides of the story.