Depression in older adults appears to significantly
increase the risk of a stroke, even after depression
symptoms have gotten better, a new study suggests. The
researchers found that people who had severe symptoms of
depression were more than twice as likely to have a
stroke as those with no symptoms. People who had
symptoms at the first interview, but had gotten better
by the second interview still had a 66 percent higher
stroke risk, the study authors said. "The surprising
finding that stroke risk remains elevated even if
symptoms seem to have gone away make replicating this
study urgent," lead researcher said. "If replicated,
these findings suggest that doctors should seek to
identify and treat depressive symptoms before harmful
effects on stroke risk start to accumulate," she said.
It's important to note, however, that this study only
found an association between depression and stroke risk.
It can't prove a cause-and-effect relationship between
these conditions, due to the study's design. Although
how stroke and depression might be linked isn't clear,
other research has shown that depression increases the
risk of high blood pressure, abnormalities in the
nervous system and increased inflammation, the
researchers said. Moreover, depression might trigger
conditions such as infection and an abnormal heart
rhythm known as atrial fibrillation, which can increase
the risk of stroke, the study authors said. In addition,
depressed people are more likely to smoke and be less
physically active, they added. For the study, researcher
and her colleagues collected data on more than 16,000
men and women. They were all 50 and older. And they were
part of the Health and Retirement Study that ran from
1998 to 2010. Over 12 years, nearly 1,200 people had a
stroke. Throughout the study period, between 10 and 12
percent of participants had high levels of depressive
symptoms. Another 8 to 10 percent of study volunteers
reported depression that had recently remitted. The
researchers didn't ask whether depressive symptoms
lessened because of treatment or for other reasons. In
addition to the overall increased risk of stroke for
people with depression, the findings suggested that
stroke risk remains elevated even when depression has
eased, especially for women, the researchers said. They
also noted that people under 65 who had depressive
symptoms had a greater risk of stroke compared to those
over 65 with depression. The study also found that
people with recent-onset depression -- depressive
symptoms that started in-between the study interviews --
didn't have a significantly increased stroke risk. The
researchers said that suggests that depression may
contribute to physiological changes over the long-term. |