Cancer mortalities linked to depression

New studies show depression decreases cancer survival rates. Tuweimei

People with cancer who are depressed are more likely to die than patients with good mental health, psychologists report in the science journal Cancer.

The study reports that death rates from cancer "were up to 25 percent higher in patients experiencing depressive symptoms and up to 39 percent higher in patients diagnosed with major or minor depression".

"In both of those groups, you can predict cancer mortality," says lead researcher Jillian Satin, of the University of British Columbia.

While the study's main conclusion is a call for more research on the links between cancer and mental health, Satin says the results also prove the link is significant.

"I think depression should always be taken seriously," she adds. "It would be my wish that this line of research fuels adding psychological social treatment into standard cancer care."

The study by Satin and co-authors Wolfgang Linden and Melanie Phillips was an overview, called a meta-analysis, of 26 previous studies on the effect of depression on the progression of cancer and survival rates of 9,417 patients.

Satin says the researchers controlled for the chicken-or-egg factor: Do people become depressed because they are sick with cancer? Or does cancer kill them more often when they have depression independent of the cancer?

"That's the million-dollar question," she says. "Even after correcting for that, we still see the positive relationship between depression predicting mortality."

But Satin warns, "I want people to be cautious about this. We have not shown that depression itself causes mortality - but we have a suggestion that this is possible."

Satin cautions against trying to match a specific patient's likelihood of death with the startling finding that death rates can be up to 39 percent higher with depression that is serious enough to be diagnosed.

"I know people want to know numbers, but I find them kind of misleading," she says. "What this is saying is that somebody's depressive status shortly after they are diagnosed with cancer predicts cancer outcomes."

The published study says its goal was to determine whether empirical evidence supports the widespread belief by both the public and cancer specialists that a patient's state of mind affects the outcome of disease.

"The field of psycho-oncology has experienced exponential growth," notes the study. "Eighty-five percent of cancer patients and 71.4 percent of oncologists endorse the belief that psychological variables affect cancer."

Satin and her co-authors note that other researchers earlier linked heart disease, depression and higher risk of death.

"Depressed patients with coronary heart disease have a two-times greater risk of mortality than non-depressed patients after adjusting for clinical factors," they note, citing another study.

AFP

taken from : China Daily