Grief and depression overlap enough that they were once separated by a rule about elapsed time. That rule was abandoned, and the distinction now rests on the shape of the experience.
Why the old time rule was dropped
Earlier diagnostic frameworks excluded a depression diagnosis for a set period after bereavement, on the reasoning that low mood following a death is expected rather than disordered.
The exclusion was removed because it left people who had developed a treatable depression after a loss without a diagnosis, and because the interval chosen was arbitrary.
The change was contested and remains so. The underlying difficulty is that the two conditions can occur separately, together, or one following the other.
How the feeling behaves over time
Grief typically arrives in waves. Intense periods are triggered by reminders and are interspersed with stretches of ordinary functioning, including moments of genuine humor and pleasure.
Depression is generally described as more continuous — a flattening that persists across contexts and is less responsive to what is happening around the person.
Clinicians therefore ask about variation rather than intensity. Whether the mood moves at all across a week carries more information than how bad it gets.
What happens to self-worth
In grief, self-esteem usually remains intact. The person feels the loss acutely without concluding that they are worthless, and guilt attaches to specific events around the death.
Depression more often involves a global negative view of the self that is not tied to any particular event. Guilt becomes diffuse and self-directed.
This distinction is one of the more useful ones in practice, because it describes something a person can recognize in their own account of how they feel.
How the person responds to others
Bereaved people usually retain the capacity to be comforted. Contact with others may be painful, but it is generally wanted and does provide some relief.
In depression, connection often fails to register. Support is offered and lands on nothing, which can leave both parties feeling that the effort was pointless.
The pattern matters because withdrawal then reinforces itself, removing the contact that would otherwise interrupt the state.
Why prolonged grief was defined separately
A distinct condition has been described for grief that remains intense and disabling long after the loss, dominated by yearning and preoccupation rather than by the flattening of depression.
Defining it separately was intended to identify people who need specific treatment without pathologizing ordinary mourning, which is a difficult line to hold.
None of these distinctions are self-applied. Anyone struggling after a loss, or unsure which description fits, should be assessed by a physician or mental health professional.