Dear Carolyn: Any advice on how to deal with my single, middle-aged, mentally ill sibling who will be attending family holiday dinners? Sibling is difficult to get along with, is out of touch with reality, and — even though aware of mental illness — won’t do anything about it. Sibling can’t be excluded because it would upset elderly parents. However, sibling drives my spouse and kids crazy. It takes a lot of restraint not to engage with sibling in an angry way. What should be a lovely family celebration will be strained at best.