The dearth of care is most evident when it comes to individuals who commit violent crimes. For example, after Liu Yalin killed and dismembered an elderly couple cutting firewood in a Guangdong Province forest, he was judged to be schizophrenic and released to his brother. Unable to afford treatment, the brother flew Mr. Liu to the island province of Hainan, in the South China Sea, and abandoned him, a Chinese nongovernment organization, Shenzhen Hengping, said in a recent report.

Last year, Mr. Liu killed and dismembered an 8-year-old Hainan girl.

“The government doesn’t want to cough up the money to treat these people, so they just give them back to their families,” said Huang Xuetao, a mental health lawyer and one of the authors of the report.

Left to their own devices, some relatives resort to heartbreaking solutions. In 2007, He Jiyue, a government psychiatrist, discovered a 46-year-old man locked behind a metal door in a stinking room in a rural Hebei Province home. The man was mentally ill, his aged parents told Dr. He. They had locked him up after he attacked his uncle.

That was 28 years earlier. The man, a high school graduate, could no longer speak. “I said to the parents: ‘How could you do this to somebody?’ ” Dr. He recalled. They replied, “We had no choice.”

In the past three years, Chinese mental health workers have rescued 339 other people whose relatives were too poor, ignorant or ashamed to seek treatment. Some, shackled in outdoor sheds, were “treated just like animals,” said Dr. Liu Jin, of the Peking University mental health institute.

Chronic shortages of both doctors and facilities ensure that what care exists is limited. China averages just one psychiatrist for every 83,000 people  one-twelfth the ratio in the United States  and most lack a university degree in any subject, much less mental health, Dr. Ma said.

“Professional psychiatrists in China are like pandas,” said Zhang Yalin, assistant director of the mental health research institute at Central South University’s medical school. “There are only a few thousand of us.”