Researchers at the National Institute on Aging say their study suggests a link between depression and cancer in elderly people RELATED VIDEO CNN's Louise Schiavone reports on a new study on depression Windows Media 28K 56K

December 15, 1998
Web posted at: 8:15 p.m. EST (0115 GMT)

WASHINGTON (CNN) -- A new study by researchers at the National Institute on Aging suggests a link between chronic depression and cancer among older patients.

"When present for at least six years, depression was associated with a generally increased risk of cancer," the researchers wrote in the Journal of the National Cancer Institute.

They analyzed the case histories of about 4,800 women and men over age 70 from Massachusetts, Connecticut and Iowa. All patients were interviewed in 1982, 1985 and 1988, and none had cancer at the time.

However, 146 of those interviewed were found to be chronically depressed.

The cancer rate among those depressed -- after accounting for age, sex, smoking and other habits -- was 88 percent higher than the other patients.

The researchers were cautious about drawing any conclusions.

"We're not saying that this is a cause and effect, that the depression directly caused the cancer and that if we treat depression we will eliminate cancer in older persons," said Dr. Richard J. Havlik.

Other scientists don't think depression and cancer are related

His colleague, Dr. Brenda Penninx, noted that other studies have shown that depression can suppress immune function by hindering the production of lymphocytes and other natural cancer-killing cells. It may also increase the release of adrenal corticosteroids, which affect blood pressure and the immune system.

Critics point out that most cancer patients are not depressed and say suggesting otherwise is dangerous.

"Stress and depression really are not scientifically established as carcinogenic factors.... You don't have to feel guilty that you're stressing or depressing yourself into a case of cancer," said Dr. John Potter, founder of the Lombardi Cancer Center at Georgetown University Hospital.

CNN Correspondent Louis Schiavone contributed to this report.