This letter discusses the current challenge in classification and treatment of DSM-5-TR prolonged grief disorder. Prolonged grief disorder (PGD) is among the new mental disorders included in the DSM-5-TR section II, a chapter about trauma and stressor-related disorders. By definition, PGD is a maladaptive response to the death of a loved one characterized by a period of at least 12 months of persistent yearning for or preoccupation with the deceased and disabling symptoms such as disbelief about the death, avoidance, emotional numbness, identity disruption, intense emotional pain, loneliness, a sense that life is meaningless, and failure to move forward. This syndrome occurs in 9.8% of bereaved survivors and may be associated with increased risk of medical conditions (e.g., cardiovascular disease, cancer, and immunological dysfunction), substance use disorders (particularly increased tobacco and alcohol use), suicidality, and diminished quality of life. Given that PGD has clinical similarities with major depressive disorder (MDD) and posttraumatic stress disorder (PTSD), recent studies have evaluated selective serotonin reuptake inhibitors (SSRIs) in the treatment of this novel DSM-5-TR diagnosis. (PsycInfo Database Record (c) 2024 APA, all rights reserved).