Updated November 20, 2014.

Definition:
An anniversary grief response occurs when an individual experiences elevated feelings of grief, sadness, loss, depression, anxiety, fatigue, anger, sleeplessness, etc., as well an increase in distressing memories, during the period leading up to, on, or even after the date on which a loved one died.

While fairly common on the first anniversary of a death, people can experience an anniversary reaction many years later -- long after coping with the grief experienced in the immediate aftermath of losing a loved one.

Moreover, an anniversary response can occur without warning due to a consciously or unconsciously perceived "trigger," such as hearing a particular song, running across a forgotten photograph, smelling a particular perfume or cologne, attending a funeral or memorial service for someone else, a scene in a movie... or any of countless other ways.

Synonyms:
Also known as an anniversary grief reaction, anniversary response, anniversary reaction, or reawakened grief.

Additional Reading:
• Coping with Grief on the Holidays