Incidence and trends in psychopathology symptoms over time in adults with severe to profound intellectual disability.

Max and colleagues tracked the adults with severe to profound intellectual disability for one full year. They used the PIMRA checklist every six months to see if psychiatric symptoms stayed the same or shifted.

All adults lived in staffed group homes and could not speak in full sentences. Most had at least one extra mental health label on file.

Total psychiatric symptom scores barely budged. The only exception was the PDD/Autism subscale, which showed a small but clear change over the year.

Other subscales like depression, anxiety, and mania stayed flat. In short, expect stability unless you are watching autism-related behaviors.

Fecteau et al. (2003) saw autistic traits improve over time, while Max found only the autism subscale moved. The gap makes sense: Shirley studied people with a wide range of IQs; Max looked only at severe-profound ID. Lower IQ may lock symptoms in place.

Edgin et al. (2017) also saw milder autism diagnoses in later birth years, but their registry data covered the whole spectrum. Again, Max’s narrow, more impaired sample explains why they saw less change.

Totsika et al. (2010) adds a twist: once you control for adaptive skills, adults with ASD plus ID show the same psychiatric levels as ID-only adults. This supports Max’s main finding that most symptom areas stay steady.

If you serve adults with severe-profound ID, do not expect global psychiatric flare-ups or quiet-downs across the year. Instead, watch autism-related behaviors closely; those can drift and may need plan tweaks. Use brief PIMRA re-screens twice a year to catch the shift without wasting time on stable domains.