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A recent study from researchers at the University of Michigan offers a mixed report on the rate of depression among older Americans.
It found that between 1998 and 2008, the rate of people aged 50 and older who reported having symptoms of depression fell significantly. Most of that decrease, however, was among people over the age of 80. Among “late middle-agers” — people between the ages 55 and 59 — the rate of severe depression actually increased.
These findings suggest that “there may be a severely ill population subgroup that is either not being treated adequately” or not responding to treatment, the researchers conclude.
The study’s findings also contradict the prevailing belief that depression is highest among the very old.
Study’s design and findings
For the study, the researchers analyzed data from the National Health and Retirement Study, which surveys a representative sample of more than 26,000 Americans over the age of 50 every two years on a variety of topics. The survey includes eight questions designed to assess symptoms of depression. Based on their scores to those questions, respondents were placed in three groups: those with no depressive symptoms, those with elevated symptoms of depression, and those with severe symptoms of depression.
The analysis revealed the following key findings:
- The rate of people aged 50 and older who reported having no symptoms of depression increased from 40.9 percent in 1998 to 47.4 percent in 2008 — an overall increase of 16 percent.
- The prevalence of elevated symptoms of depression among people aged 50 and older declined 7 percent, from 15.5 percent in 1998 to 14.2 percent in 2008. That drop was most pronounced, however, among people aged 80 to 84, in whom the rate fell from 14.3 percent to 9.6 percent.
- The prevalence of severe symptoms of depression among people aged 50 and older increased from 5.8 percent in 1998 to 6.8 percent in 2008. But that increase was almost entirely driven by people in the 55- to 59-year-old age group, for whom the probability of having severe symptoms rose from 8.7 percent to 11.8 percent. No change in severe symptoms was seen among people aged 50 and above.
Overall rate still high
Although the study found that the overall rate of depression symptoms declined between 1998 and 2008, that rate was still high. More than 50 percent of the older people surveyed reported elevated or severe levels of symptoms.
The study also found that certain sub-groups of people over the age of 50 were at greater risk of reporting symptoms of depression. These sub-groups included women, Hispanics, smokers, and people with chronic or physically limiting health problems, as well as those who were unmarried or who had lower levels of education and/or income.
People who were retired were also at higher risk of being depressed, although why that is so is not clear. It may be that retirement makes some people more vulnerable to depression, or it may be that people who are depressed are more likely to retire, the authors of the study point out.
As for the troubling increased rate of symptoms of depression among people aged 55 to 59, the study’s authors say more research is needed to determine the cause of that trend. It may be that people in that age group had more limited access to treatment for depression in 2008 than in 1998.
It will be interesting to see if the trends revealed in this study have continued past 2008. That year, of course, marked the start of the Great Recession, when job losses, home foreclosures, and bankruptcies were beginning to mount. Research has suggested that middle-class, middle-aged people have been among the hardest hit by that economic downturn.
The U-M study was published in the July issue of the Journal of General Internal Medicine.