Kübler-Ross model

"The Kübler-Ross model, commonly known as the five stages of grief, was first introduced by Elisabeth Kübler-Ross in her 1969 book, On Death and Dying.
It describes, in five discrete stages, a process by which people allegedly deal with grief and tragedy, especially when diagnosed with a terminal illness or catastrophic loss. In addition to this, her book brought mainstream awareness to the sensitivity required for better treatment of individuals who are dealing with a fatal disease."