Abstract: The proposed changes to DSM-5 will create new categories of mental disorder (referred to here generically as Prolonged Grief Disorder’’ [PGD]) to diagnose individuals experiencing prolonged intense grief reactions to the loss of a loved one. Individuals could be diagnosed even if they have no depressive or anxiety symptoms but only symptoms typical of grief (e.g., yearning, avoidance of reminders, disbelief, feelings of emptiness). The main challenge for such proposals is to establish that the proposed diagnostic criteria validly discriminate a genuine psychiatric disorder of grief from intense normal grief. With this test in mind, I evaluate the soundness of four empirical arguments and one conceptual argument that have been put forward to support such proposals: (1) PGD has discriminant validity because distinctive, pathognomonic symptoms distinguish it from normal grief; (2) PGD has discriminant validity because it identifies grief symptoms that are of greater absolute severity than in normal grief; (3) PGD has predictive validity because it implies a chronic, interminable process of grieving, thus a derailment of the normal process of grief resolution; (4) PGD has predictive validity because it predicts negative mental and physical health outcomes unlikely in normal grief; and (5) PGD has conceptual validity because grief is analogous to a wound or, alternatively, lengthy grief is analogous to a wound that does not heal. Upon close examination, each of these arguments turns out to have serious empirical or conceptual deficiencies. I conclude that the proposed diagnostic criteria for PGD fail to discriminate disorder from intense normal grief and are likely to yield massive false-positive diagnoses. Consequently, the proposal to add pathological grief categories to DSM-5 should be withdrawn pending further research to identify more valid criteria for diagnosing PGD.