An old woman in a state of depression murdered her 8-month-old granddaughter in south China's Hunan Province last month, stirring up public concern regarding the mental health of the country's elderly population.

Psychologists confirmed that violent crimes perpetrated by elderly citizens have become more frequent in recent years, as the country's aging population has increased significantly.

No rhyme or reason

For most people, it is inconceivable to even think that a doting grandmother would be capable of killing her own granddaughter. However, that is precisely what happened on June 18 in a rented house in the city of Hengyang.

A 63-year-old woman surnamed Yang decapitated her 8-month-old granddaughter with a kitchen knife while her daughter, the baby's mother, was shopping for groceries.

The grandmother then washed the blood off of her hands and went to the police to confess to the crime.

Yang was arrested by the local procuratorate on July 7, according to the police.

Expert testimony has shown that Yang suffered from depression for about two years before the murder. She was also found to be taking psychotropic drugs after being discharged from a hospital last year following a suicide attempt.

"I was upset that day after taking some drugs," Yang recalled. " My son-in-law always quarrelled with my daughter about the baby. He took my daughter's money to use for gambling. I felt so angry that I sought revenge through the child," she said.

Yang's own son said that his mother preferred not to talk to others after the death of her husband in 2004.

"Our family moved to this district in 2009. Since then, my mother has stayed at home and cared about nothing," he said.

As time went by after her husband's death, Yang began to slip into depression, with her illness becoming so serious that she attempted suicide in 2010. She was sent to the hospital six times that year to receive treatment.

Yang's neighbor, a man surnamed Liu, said that he saw the old woman weeping by herself on several occasions.

"She is not local. She is a stranger here," Liu repeated several times in reference to Yang.

To him and Yang's other neighbors, it seemed difficult for Yang and her family to blend into the local community.

Wake-up call for mental health care

"In this case, dissatisfaction with her son-in-law and a period of depression drove the woman crazy and led to the tragedy," said Shi Yu, a psychology expert with the General Hospital of the Armed Police Force.

Chinese families have a tradition of asking their elders to help take care of the youngest family members. This can create additional stress and pressure for elderly people, who often have their own battles to wage against illness and old age.

Instead of only providing material necessities for elderly people, families should pay more attention to their parents' mental health and give them more care and attention, Shi said.

According to the results of last year's census, people aged 60 years or older accounted for 13.26 percent of China's total population as of the end of 2010, a 2.93-percent increase over the number recorded during the country's 2000 census.

The rapid increase in the size of the country's aging population has brought with it a wave of problems, including increasingly frequent cases of senility and other mental illnesses.

Experts say that economic backgrounds and a transformation in the traditional family structure, along with a lack of care from children and reduced communication with the outside world, are to blame for the mental health issues currently facing senior citizens.

"The mental health issues surrounding the elderly population need to be addressed not only by senior citizens and their families, but also through comprehensive measures put in place by the government and society," said Yang Fangru, a psychology professor at Central South University.

The government of central China's Hunan Province launched a campaign this month to encourage university students to show more respect and care for elderly people.