This article from Scientific American covers two proposed changes to the DSM-V that would classify grief differently:
In the less controversial change, the manual would add a new category: Complicated Grief Disorder, also known as traumatic or prolonged grief. The new diagnosis refers to a situation in which many of grief’s common symptoms—such as powerful pining for the deceased, great difficulty moving on, a sense that life is meaningless, and bitterness or anger about the loss—last longer than six months. The controversial change focuses on the other end of the time spectrum: it allows medical treatment fordepression in the first few weeks after a death. Currently the DSM specifically bars a bereaved person from being diagnosed with full-blown depression until at least two months have elapsed from the start of mourning.
There is much talk about the new DSM-V, and this proposal will likely ensure that the discussions continue.