Even if one denies the spiritual dimension, there’s no denying the power of the mind over the body, and as you pointed out, this can be exhibited in cases of grief. My Great-Grandmother tried to soldier on after her husband’s death, but a couple of weeks passed and she just slipped away.
Before my grandmother died int he 1970s, she was in a hospital room with another elderly woman.
I went to visit granny and asked how she liked her roomate.
Granny told me “That woman has done something awful in her life.” She said the woman was in mental agony, begging for forgiveness, constantly sobbing and begging for forgiveness.
Also I know someone who was married to a woman who had an abortion in England, before they were legal here. The woman later lost her mind, and would meet her husband at the door when he came home from work screaming at him “You told them, you told the TV and newspaper reporters.” She’d wave a newspaper at him and swear the stories in there were about her abortion.
I couldn’t imagine having to live knowing I had taken the life of an innocent child.