Office of Research & Development

Feature Article

Study confirms that depression can shorten life

It's long been believed people with major depression and some other serious mental illnesses tend to live shorter lives than others—and die more quickly than expected when they develop illnesses such as cancer, heart disease, stroke, and diabetes.

However, the studies that contributed to this understanding were of patients who were under psychiatric care for their mental illness, not of all patients with depression. These included a 2008 VA study, published in the Journal of the American Medical Association, which found that depression led to heart disease because people who were depressed exercised less and smoked more than those who were not.ⁱ

A new VA study, published in the Aug. 1, 2012, issue of the journal Psychiatric Services, provides new information on the toll depression takes on all patients with the illness, not only those receiving psychiatric care. The study compared the ages at death among all VA patients with a diagnosis of depression, whether they were currently under treatment or not, with the ages at death of other VA patients. ⁱⁱ

Researchers found VA patients with depression died, on average, five years earlier than VA patients without that diagnosis. In addition, compared to other Veterans, people with depression lost more years of productive life they might otherwise have been expected to live.

"Our goal was to extend the prior research that's been done on depression and mortality [death], and to examine the specific causes and timing of mortality among depressed Veterans," explains Kara Zivin, PhD, lead author for the study. "We examined the years of potential life lost associated with 13 specific causes of death, as well as mortality from all causes among VA patients with and without depression."

Zivin is a researcher with VA's Health Services Research and Development (HSR &D)/Serious Mental Illness Treatment Resource and Evaluation Center (SMITREC) in Ann Arbor, Mich., and an assistant professor of psychiatry at the University of Michigan. The team's research was funded by HSR&D.

The team looked at the electronic health records of nearly five million VA patients, all of whom had used VA health care in fiscal year 2006 (from October 1, 2005 through September 30, 2006). They found that slightly more than 700,000 of those patients had a diagnosis of depression. In fiscal year 2007 (October 1, 2006 through September 30, 2007), just over 167,000 (3.38 percent) of these patients died.

The average age at death for patients with a diagnosis of depression was 71.0 years; those without such a diagnosis were 75.9 years old at the time of their deaths. By dividing the patient population into eight age groups, and using life expectancy tables developed by the Centers for Disease Control, they were able to calculate the years of potential life left those who had died could normally have anticipated.

The formula they used was to take the midpoint of each age group, add the number of years the CDC table estimated people of that age should live, and then subtract the actual age at death for Veterans in that group who had died in fiscal year 2007. This method allowed them to evaluate the impact of early death on an entire population, not just on those who died younger than a specified endpoint age, such as 65. They found that depressed patients who died in fiscal year 2007 lost, on average, 13.4 years of productive life—while non-depressed patients lost only 10.9 such years.

In fact, depression was associated with significantly earlier ages at death and more years of productive life lost for all of the 13 causes of death that were examined in the study. These included accidents, cerebrovascular issues, diabetes mellitus, heart disease, homicide, influenza and pneumonia, liver disease, malignant neoplasms (cancer), nephritis (kidney disease), respiratory disease, septicemia (blood infection), and suicide. All other causes of death were included in a 14^th category—and here, too, death came earlier for depressed patients.

"These findings highlight the importance of depression as a potential contributor to early mortality," says Zivin. "Since depression is treatable, such treatment could have a measurable impact on the risk of early death."

The paper also suggests that improvements in the quality of mental health care depressed patients receive could reduce mortality in those groups, and that better overall management of their care could also reduce their risk of early death.

In recent years, VA has enhanced services to its seriously mentally ill patients by integrating mental health care into the primary care setting, developing an extensive suicide prevention program, and increased the number of Veterans Readjustment Counseling Centers (Vet Centers.) VA's Veteran Crisis Line has received more than 600,000 calls, resulting in over 21,000 rescues of Veterans in immediate crisis.

At the direction of Secretary of Veterans Affairs Eric K. Shinseki, VA is in the process of adding approximately 1,600 mental health clinicians, including nurses, psychiatrists, psychologists, and social workers, to its existing workforce of more than 20,000 mental health staff as part of an ongoing review of mental health operations. VA is also adding 300 support staff members to help these clinicians accomplish their missions.

VA Research is doing its part to ensure that all Veterans receive world-class mental health care. VA investigators are pioneering advances in the understanding and treatment of mental health disorders. In addition to the study above, VA researchers are looking at potential approaches for treating and preventing mental health disorders, and also at related issues such as developing and evaluating collaborative primary care models and improving access to services from remote areas using the Internet and other technologies.