Have you had a similar experience?

Hello. My dad is 72 years old. Since more than one year he is experiencing several symptoms which are typical of a dementia condition like Alzheimer although he does not have some others that are as well important for such a diagnosis. He is being checked by a neurologist and psychologist but it would help me if someone has experienced similar cases and can provide good advises. The main symptoms are:
- loss of short term memory: sometimes he asks the same question that he has asked a few minutes before
- he does not participate to conversations, he is very passive for example when we seat around the table with relatives or friends
- he says that sometimes he knows well the word for something but he cannot simply say it
- he says that he prefers to stay home because he is afraid that people will ask him questions and then he will not be able to reply
- sometimes he starts telling a story but he cannot complete it
- very often he puts his hands on his head and/or face to cover them and does nothing but rubbing his head/face
- sometimes you ask him why he wants to do something and he replies "I don't know, I don't have anything to say"

He has no problems with walking or recognizing people or finding the way home. He had a major heart problem some years ago an he takes quite a lot of medicines, so maybe this plays also a role.

I don't know whether he has first symptoms of Alzheimer or if he has a serious form of depression (or both).

If some of you has experienced a similar situation, would be great if you could share some good advises or tips.

Thank you!

Mike