My dad keeps asking about my brother, and always imaging the worse, (my brother works in another city) and keeps complaining about how bad his life is, and sometimes he wishes death! He also refuses to get help thinking it won’t work. Are these a signs of depression? And can it be prevented?
Many elderly people feel the way your dad does. They resent their illness or their decline. They resent needing help. And that resentment can turn into depression.
Take your dad to his Dr. and talk to the Dr. about this. He may put your dad on an anti-depressant and while you wait for several weeks for it to kick in get your dad out and about doing things if he is able.
However, a pill won't fix what's broken with your dad. It won't give him back his youth or his health but it may improve his mood.