Yes, I agree.  It is unfortunate that there are such horrible diseases out there.  My mother is suffering from dementia now and her personality has shifted 180 degrees due to it.  But when you think about it, any contract signed by an individual who is not in their right state of mind is considered null and void.  You are correct, it is not that simple and there is definitely no black and white in our line of work.  There are many gray areas which we need to use our best judgment to make decisions on, but it needs to be done.  And when firing a client, we don't necessarily need to be mean or rude.  The only client I fired, I showed respect even though he was very rude, abusive, and always found ways to take advantage of my patience.