A "stressed" carer who killed her sick mother by giving her an overdose of insulin and smothering her with a pillow has been admitted to a psychiatric hospital indefinitely.
Devoted Shirley D'Silva, 55, had looked after Martha Pereira at home after she began suffering from dementia, lung cancer and diabetes.
But on the afternoon of October 25 last year, the married mother-of-two called 999, saying: "I murdered my mother ... I've given her insulin and then I put a pillow on the top of her mouth."
Asked why she did it, the trained nurse said: "It's the world we live ... The war around the world."
When police arrived at the family home in Morland Road, Croydon, south London, they found 77-year-old Mrs Pereira dead.
D'Silva (pictured) told police she heard a voice in her head telling her to kill her mother, the Old Bailey heard.
A post-mortem examination found that none of Mrs Pereira's illnesses contributed to her death, which was found to be consistent with D'Silva's explanation.
Prosecutor Oliver Glasgow QC told the Old Bailey that D'Silva had a history of mental illness and was sectioned in 1996 after she tried to commit suicide.
A psychiatric report found she had been "actively psychotic" at the time of the killing and had paranoid schizophrenia.
Dr Frank Farnham wrote in his report that D'Silva's psychotic symptoms had "fluctuated in intensity since her original overdose in 1996 but that her mental state has deteriorated in recent months as a result of the stress of caring for her mother".
On Monday, D'Silva pleaded guilty to manslaughter on the basis of diminished responsibility, which was accepted by the prosecution.
Her husband, Joe D'Silva, who attended court with other family members, described her as "devoted to her mother".
He wrote: "She never asked for help and she was very close to her mother."
The family, who supported the defendant, found it "very difficult to comprehend this has happened", said Judith Khan QC, mitigating.
Judge Nicholas Hilliard QC handed D'Silva a hospital order with a restriction order without limit of time and returned her to River House at Bethlem Royal Hospital in south London.
On her care for Ms Pereira in the past, the judge told the defendant: "There is nothing to suggest you did not ordinarily look after her properly.
"She had lived with you for a number of years and there is evidence you were devoted to her.
"But on 25 October last year you gave her insulin, having set the administration device to maximum, and then smothered her with a pillow.
"But for mental illness for which you are not responsible, you would not have committed this offence."
Detective Sergeant Brendan Ward, from the Metropolitan Police, said: "This is a very sad case and our thoughts and sympathies are with the family at this difficult time."
Copyright (c) Press Association Ltd. 2017, All Rights Reserved. Pictured (c) Met Police / PA Wire.