Dear Eric: I am 75 years old. My wife and I have been married for 45 years. My wife suffers from treatment-resistant depression and/or bipolar disorder. My wife has been undergoing treatment of various kinds for 30 years without success.

Mental health professionals and close friends have told me that my wife is damaging my mental health and advise me to leave. I have not left her because I vowed not to do so, and she is dependent on me. She would be devastated.