Is it OK to fulfill someone's delusions to maintain peace?

An expose into how a close relative can drive a sane person to insanity all for the purpose of playing by their tune of illusion

In order to respect your elders, is it morally right to accept responsibility for mishaps in their life when you had no control, involvement or were not even born then?! How to handle such delicate situations when people are temperamental, upstrung & unwilling to seek professional help...