Children born during China’s 1959-61 famine were twice as likely to develop schizophrenia, confirming a link between nutritional deficiency and the mental illness, according to new research.

Schizophrenia afflicts roughly 1 percent of the global population and tends to run in families, but the incidence of the illness has been found to have doubled during famines in China and the Netherlands.

The Chinese findings mirrored those from an earlier study of schizophrenia rates among people born in the Netherlands during the “Dutch Hunger Winter” of 1944-45.

Researchers from Shanghai Jiao Tong University, writing in the Journal of the American Medical Association, examined records from around the city of Wuhu in Anhui Province, where the famine was acute and people starved to death in large numbers. The famine followed a season of bad weather and rural upheavals created by the government’s “Great Leap Forward.”

Out of more than 600,000 births during the period studied there were 4,600 schizophrenia cases. During the famine years, the birth rate declined 80 percent and the percentage of children who went on to develop schizophrenia rose from less than 1 percent to as high as 2.2 percent.

Study author Dr. David St. Clair wrote that “extreme stress” on prenatal development such as from a famine results in schizophrenia among those genetically predisposed to the illness. He cited a theory that the normally tightly regulated development of the brain can be disrupted by a nutritional deficiency.

Schizophrenia usually manifests itself in late adolescence or early adulthood and is present in all societies and racial groups, as reflected in the similar outcomes of the Chinese and Dutch famines, St. Clair wrote.

Writing in an accompanying editorial, Richard Neugebauer of the New York State Psychiatric Institute said the challenge is pinpointing what is missing from diets that could be an underlying cause of schizophrenia - and whether the deficiency can be compensated for.