Thank you for mentioning this.

This is a very important thing to keep in mind indeed. Dementia sufferers often are not cognizant of when the illness starts creeping on them. It is, usually, more obvious to outsiders. My both parents suffered from dementia, which manifested more heavily in my mom, so I've seen how unaware people with this condition may be.

When this is the case, people who are close to the person-family, friends, colleagues should have a conversation with them as soon as they see the signs of illness. The sooner it happens, the greater the chance is that the person would be able to be receptive to the feedback and to take some protective measures for the future that would prevent potential harm they could inflict on others and on themselves if their mental health continues to deteriorate.

In psychotherapy, for better or for worse, age is not considered a limitation but rather an asset, as the old age is often associated with wisdom. Because of that and because the work is not physically or intellectually demanding, many therapists are old, and, I mean, REALLY old. And, since they often practice in isolation, oftentimes, there aren't many people around who could let them know that they are starting to lose it..

In the ethical code it says that it is ethical responsibility of each professional to have an honest and compassionate conversation with a colleague, who is becoming or has become incapacitated and unfit to practice. Unfortunately, ethics don't mandate professionals to report such colleagues in case if they are not receptive to the feedback and not willing to address their condition.