John Bowlby, the developer of attachment theory, said, “There are few blows to the human spirit so great as the loss of someone near and dear.”
Undoubtedly, the best-known grief theory is Elizabeth Kübler-Ross’s five-stage theory described in her book On Death and Dying. While the book was about facing one’s own death or that of a loved one, the stages can often apply to losses that arise from any life-changing event in which a person experiences a profound loss, such as trauma, the loss of one’s home or job, or divorce—and, specifically, for adult children, the feelings of loss brought on by their parent’s “gray divorce” (the term for a split that occurs in a couple over 50). Kübler-Ross explained that these stages are not linear, as people may often move back and forth between them: