Doctors have known for years that depression and anxiety can increase a person's risk of dying at an early age—especially if the symptoms are serious or stem from a devastating life event, such as the loss of a loved one. But what about the run-of-the-mill sadness and worry so many of us carry around?
These everyday problems may take a toll as well. According to a new study published today in the British Medical Journal, even mild symptoms of depression and anxiety that would generally escape a doctor's attention are associated with a higher risk of premature death.
Researchers in the U.K. pooled data from 10 previous studies involving more than 68,000 British adults ages 35 and up. All of the study participants answered a list of questions about so-called psychological distress in their day-to-day life, such as whether they felt unhappy, were sleeping poorly due to stress, or had feelings of worthlessness or low self-esteem.
People who reported the most psychological distress were two-thirds more likely than happy people to die during the various studies, which lasted for an average of about 8 years. But even those with the lowest levels of distress had a 16% higher risk of dying compared to distress-free people.
The participants with only mild distress "would not have sufficient symptoms to be diagnosed with an anxiety disorder or a depressive illness were they to present to a doctor," says lead author Tom Russ, MD, a researcher and Alzheimer's disease specialist at the University of Edinburgh, in Scotland.
"However," he adds, "even these individuals are at an increased risk of dying from various major causes. [This] means that even these minor symptoms of anxiety and depression should be taken seriously."
The risk of dying prematurely varied by cause of death. Compared to happy people, those with low levels of psychological distress were 23% more likely to die from accidents or injuries and 25% more likely to die from heart disease, strokes, or heart failure. By contrast, an increased risk of fatal cancer was apparent only among the most distressed people.
What explains these relationships? The extenuating factors the researchers took into account—such as smoking, body mass index, physical activity, alcohol consumption, and social class—didn't appear to play a large role, so the answer probably lies elsewhere.
One possibility, the authors say, is that psychological distress promotes inflammation and the release of stress hormones, which have a demonstrated ill effect on heart health as well as cancer.
For instance, surges of adrenaline and other stress-related body chemicals can cause the fatty plaques in narrowed arteries to rupture, leading to blood clots, heart attacks, and strokes, says Christopher Cove, MD, a cardiologist and associate professor of medicine at the University of Rochester Medical Center, in Rochester, N.Y.
Being distracted by psychological distress could even contribute to fatal car accidents and injuries, says Cove, who was not involved in the study.
Almost everyone experiences some feelings of depression or anxiety, and the study authors emphasize their goal is not to recast normal distress as a dire medical condition.
"We are not advocating widespread medicalization or pathologizing of such distress, and certainly would not suggest that medication would be appropriate for these people," Russ says.
But non-drug remedies for depression and anxiety—such as exercise or lifestyle changes—may prove beneficial to people with mild psychological distress, Russ says. More research will be needed to test whether these and other treatment strategies can boost overall health and affect longevity.