Today, the concept of stages of grief or the idea that grief follows a standard pattern is not widely embraced by experts. Colin Murray Parkes, a psychiatrist who has written extensively on bereavement, proposed a variation: that people who have experienced a loss undergo phases of numb disbelief, yearning for the deceased, disorganization and despair, and finally reorganization, during which they carve out a new life. The road to this new life may be long. According to Parkes, people must go through a painful period of searching for what has been lost before they can release their attachment to the person who died and move forward. When enmeshed in disorganization and despair, people find themselves repeatedly going over the events preceding the death as if to set them right.
J. William Worden, a psychologist who taught at Harvard Medical School, suggested a model of grieving that includes certain tasks. The first three tasks are to accept the loss, experience and work through the resulting pain, and adjust to a changed world without the person who has died. The fourth and final task is to alter ties with the deceased enough that you're able to invest your love and energy in others. People may shuttle back and forth among these tasks, but Worden warns that failing to complete all of them is like healing only partially from a wound.