Unfinished Goodbye

We are taught how to grieve when someone passes away. There are rituals, funerals, and a clear-albeit painful-understanding that a life has ended. But how do you mourn someone who is still physically present but psychologically absent, like a parent with severe dementia? How do you grieve a family member who has chosen estrangement, or a partner who simply walked away without a word? This agonizin...