Beginning of the year
Della suffered from cardiac and respiratory disorders, and her health condition began to get weaker.
So Gladys had settled at ther mother's house in Hawthorn .
The Consolidated Film Industries having merged with the Bennett Film Labs, had settled on Santa Monica Boulevard, which for Gladys, increased her travelling time (she had to change the trolley twice) to go to her work.
Moreover, she quickly quit her job.
End of Spring
Della was in bad condition. Her respiratory problems were worsened by her heart disease evolution, which dropped her in a deep nervous breakdown. The drugs only allayed her occasionally.Between the intervals, as many sick people affected by cardio-respiratory problems, she drifted in pleasant reveries, delirium and some moments of total exhilaration. Gladys couldn't keep her from thinking of the whimsical behaviour of her father, during his last years (he had died in 1909 from a dementia subordinate to the syphilis).
Della was convinced that it was the end of her life. The guiltiness and the memories alternated with
hallucinations : her parents, Tilford and Jenny Hogan () had buried the hatchet, she told Gladys. They would rescue her and bring her back to her home. She also complained about the return of her ex husband, Charles Grainger, who came, according to her, to rape her.
Shortly after, she get out of her house and walked toward the Bolenders house to see her grand-daughter.
She beat at the door then angry not to obtain an answer, she broke the window glass with her elbow.
It's reported that she tried to suffocate Norma Jeane with a pillow (a memory described by Marilyn herself)
On Thursay, August 4, Della was admitted to the Norwalk
State Hospital where an acute myocarditis was diagnosed.
She died on August 23 of a heart failure during a insane attack, that Gladys, then Marilyn herself, would consider as an inherited malediction.
As cause of death, her certificate mentioned a myocarditis and also "a manic-depressive psychosis"
This last word had been added because Gladys hadn't ceased to repeat to the Norwalk State Hospital doctors that her mother mood had varied in an unexpected way during the last weeks. But her medical file didn't mention any psychiatric or neurologocal analysis.So it seems that Della died from her cardiac illness which caused, by a lack of oxygen, a cerebral suffering manifested itself by acute behavior disorders.
Like for her first husband and Gladys father, Otis Monroe, nothing proves the existence of Della's mental disorders, but rather behavior disorders subordinate to a physical illness.
To Gladys, and with the elements she got at that time, the myth of a familial dementia was only growing stronger.
The death of her mother deeply depressed her. Locked in the bungalow of her mother, she meditated for a long time.