I have often thought that the mean, angry, selfish, cheap, entitled people who were some of Gregory's architecture clients (some were wonderful) helped bring on his Alzheimer's.
I first noticed the changes at the point of his dealing with one of his most manipulative, mean clients. Gregory had been hiding the client's dissatisfaction and threats and when it came out and I questioned him, told me "I thought that if I did a really good job they would come around."
Also during the last month before his psychotic episode, when he seemed to be reliving something in the past, he was talking about "those mean evil people" in very angry tones.
Being such a loving, accepting, calm person he worked so hard to be good to and for his clients and many took advantage of that. Could this have been what "broke" him?