Thank you very much for your reply. I think it is certainly worth trying and I do try to change the subject and make 'small talk ' with him when I visit. My mum finds it very difficult to take, though, because he doesn't remember they are married. (He sometimes thinks he is a prisoner and she is his warder!!.) However, no matter how many times she repeats the truth to him about his family and where he lives, he still keeps asking and does become very distressed. I will gently pass this advice on to her and see if it makes things a little easier for them both.