Even Mild Anxiety May Shorten a Person's Life
Study: Low Levels of Anxiety or Depression Are Tied to an Increased Risk of Death
July 31, 2012 -- Psychological distress, even at relatively low levels, is linked to an increased risk of death, a large new study shows.
Distress is a measure of psychological health that takes into account symptoms of anxiety or depression.
The study found that people frayed by even slight distress, meaning they sometimes stayed awake at night worrying or had trouble concentrating on tasks, for example, were about 20% more likely to die over a 10-year period compared to people who reported no such symptoms.
That was true even after researchers adjusted their results to account for unhealthy behaviors that often accompany anxiety and depression, like smoking and excessive drinking. They also accounted for things like exercise, weight, and diabetes.
The study can't prove that being anxious or depressed leads directly to a person's death. Other studies looking into the connection have been unable to discover which comes first: Does a person get sick because they're depressed? Or do people get depressed because they're sick?
In this study, though, researchers discounted all early deaths -- those that happened in the first five years of the study. That makes it less likely that illness caused people to become worried and depressed.
"It is a very impressive study," says Glyn Lewis, PhD, professor of psychiatric epidemiology at the University of Bristol in the U.K. Lewis wrote an editorial on the study but wasn't involved in the research.
Anxiety, Depression, and the Risk of Death
For the study, which is published in the journal BMJ, researchers pooled information on more than 68,000 adults over age 35 who took part in England's National Health Survey from 1994 to 2004.
Each person who participated completed a 12-question mental health survey. The survey asked about things like having trouble concentrating; losing sleep over worry; feeling useful, capable, or under strain; having trouble overcoming difficulties; not enjoying activities; being able to face their problems; feeling unhappy, depressed or worthless; or lacking self-confidence.
Researchers then divided the scores into four groups. People with a score of zero weren't distressed at all. They were used for comparison. Those who scored one to three on the test were considered mildly distressed. These people had some symptoms of anxiety and depression, but they wouldn't necessarily have come to a doctor's attention for their troubles. Scores of four to six were in the range that people might be clinically depressed or anxious. Scores of seven to 12 were people who had been severely distressed.
Researchers then linked the information on the people in the study to British death records. More than 8,300 people in the study died, most from heart disease or stroke (3,382), followed by cancer (2,552) and so-called "external" causes -- mostly accidents and injuries (386).