I can confirm that Ashley is spot on. My Dad has dementia/Alzheimers and is now in a care home, I see an 'Ashley' everytime I go there, they are the ones in the first stages, who get very easily confused and upset. The latter stages are horrific, and that's the sad part, Ashley will continually deteriorate, probably over years.
However, off key a bit, but in my view, Ashley is played to perfection by John, it's very upsetting, but accurate.