Even moderately depressed seniors, the University of Michigan study finds, require far more hours of care than those without any symptoms of depression, regardless of other health problems they may have.
If depressed seniors' "informal" caregivers were paid the wages of a home health aide, the cost to society would be $9 billion a year, the researchers estimate. That puts depression second only to dementia in the national annual cost for informal caregiving, based on previous studies of the same data. And the findings illustrate the major impact of depression on both seniors and their loved ones.
The findings, which will be published in the May issue of the American Journal of Psychiatry, are based on data from the U-M's Health and Retirement Study, a long-term survey of older Americans conducted by the U-M Institute for Social Research. The study's authors, from the U-M Health System's departments of Internal Medicine and Psychiatry and the VA Ann Arbor Healthcare System, analyzed data from 6,651 people over the age of 70 from around the nation. It's the first analysis of its kind.
In all, 18 percent of the seniors reported having had four to eight depressive symptoms in the last week on a standardized survey. Another 44 percent had one to three symptoms. These proportions are in line with previous estimates of depression's incidence among older people; about 1 to 5 percent are thought to have serious, major depression, while another 7 to 23 percent may have mild depression.
The survey showed that 38 percent of seniors who had many depressive symptoms, and 23 percent of those with a few symptoms, reported receiving informal care from family or friends -- but only 11 percent of those without depressive symptoms did.
"People with many depressive symptoms also had a significantly higher likelihood than others of needing help with tasks such as dressing, bathing, eating, grocery shopping, taking medicines, paying bills and using the telephone," says lead author Ken Langa, M.D., Ph.D., an assistant professor of general medicine and faculty associate of ISR. "Even those with just a few depressive symptoms were more likely to need help with these everyday activities than those without signs of depression."
In all, the seniors with many depressive symptoms required six hours a week, on average, of help from unpaid caregivers -- more than twice as much as the 2.9 hours for those with no symptoms. Those with few symptoms got 4.3 hours of care a week.
Even when the researchers took into account the other chronic health problems that the seniors faced -- from heart disease and diabetes to arthritis and vision problems -- those with depressive symptoms still needed more care than those without.
If the informal caregivers were paid the median home-health aide hourly wage from the year 2000, around $8.23 an hour, and if the incidence of symptoms and use of care in seen in the study were extrapolated to the entire U.S. population over the age of 70, the total bill for the informal care of seniors with depressive symptoms would be about $9 billion a year, the researchers calculate.
This is on top of the cost of formal paid care, medications, doctor visits, and other costs related to depression.
And, it's a conservative estimate based only on hours of direct care, not including time spent driving to doctor appointments or the store, or other indirect services.
"We feel we've been able to quantify for the first time what physicians and caregivers already know: that depression in older people leads to difficulty in getting through the day, and that they tend to rely on their families more for even basic tasks," says co-author Marcia Valenstein, M.D., a U-M psychiatrist who treats older people with depression at the VA Ann Arbor Healthcare System. "When there isn't a committed caregiver, the risk rises that a person's care needs will go unmet."
Adds Langa, "It's a sort of chicken-and-egg problem: the symptoms of depression make it harder to care for yourself, and those with illnesses that make them less independent often become depressed. But no matter which came first, better recognition and treatment of depression among the elderly could improve a patient's outlook and probably reduce the burden on the family. This is especially true for those with other health problems that require complex self-management."
Senior author Sandeep Vijan, M.D., M.S., adds, "Chronic diseases such as depression have an effect on society that extends beyond the patient. This study shows that the impact on families and caregivers is significant in terms of time and cost. The medical community often overlooks these factors when considering the best way to care for patients, but it is vitally important to consider the broad picture when making decisions on treatment and health policy."
Langa notes that the data used in the analysis are from 1993, before the new generation of anti-depressant medications became widely used and accepted, and before they were marketed directly to the public. The U-M team is now working to analyze data from the years 2000 and 2002, to see if there has been any change. All the data are from the Asset and Health Dynamics among the Oldest Old, or AHEAD, cohort of the Health and Retirement study.
The researchers found that older women, especially those without spouses, were more likely to have many symptoms of depression.
"This increased risk, combined with less social support and fewer financial means to pay for help, means they are especially likely to go without necessary care and assistance in everyday tasks," explains Langa. He and other U-M authors published a paper in 2000 in the Journal of the American Medical Association detailing dramatic differences in home care, social support and net financial worth for disabled women as compared with disabled men.
Langa and his colleagues hope their study alerts physicians to the importance of paying extra attention to the depressive symptoms and caregiving needs of older women living alone.
They also hope their results will give physicians, policy makers and others a better sense of the relative importance, and cost, of depression among the elderly. The U-M team previously studied the costs of informal caregiving for elderly people with other chronic conditions, including diabetes, urinary incontinence, stroke and dementia.
Although the estimated cost per person of informal care was highest for people with dementia and stroke, the high incidence of depression raises the total annual national cost. In all, depression's $9 billion cost is second only to dementia's $18 billion cost.
"Physicians have long been aware of the difficulties faced by caregivers of patients with dementia, and the time commitment of caring for them," says Valenstein. "This study shows that we also need to be tuned in to the time commitments and stress faced by caregivers of people with depression."
Besides Langa, Valenstein and Vijan, the authors are Mark Fendrick, M.D. and Mohammed Kabeto, M.S. The study was funded by the National Institute on Aging and the Alzheimer's Association.