My father passed away more than 20 years ago, and my mother has never remarried. She was never serious about trying to remarry, and only had one serious relationship after my father's death. Now that her children are married and gone, I worry that her loneliness in aging is causing a depression. She makes comments that worry me and my family, like how she has nothing left to look forward to. How can I help my mother find purpose again, and how can I encourage her to get help if she needs it?