And the greater the level of psychological distress, the higher the odds of death from heart disease, the researchers say.
“The fact that an increased risk of mortality was evident, even at low levels of psychological distress, should prompt research into whether treatment of these very common, minor symptoms can reduce this increased risk of death,” said lead researcher Tom Russ, a clinical research fellow at the Alzheimer Scotland Dementia Research Center of the University of Edinburgh.
For the study, published online July 31 in BMJ, Russ and colleagues analyzed 10 studies of men and women enrolled in the Health Survey for England from 1994 to 2004. Data on more than 68,000 adults aged 35 and older was included overall.
Each study looked for connections between chronic psychological distress and the risk of dying from heart disease and other causes, including cancer.
Pooling data in this way is called a meta-analysis. In such a study, researchers look for common patterns across several studies.
Over eight years’ follow-up, the researchers found even very mild depression or anxiety — subclinical levels — raised the risk of all-cause death, including cardiovascular disease, by 20 percent. Looking specifically at death from heart disease, mild psychological distress raised this risk 29 percent, the study found.
For the highest level of depression or anxiety, the risk of all-cause death rose 94 percent, the researchers found.
Risk of death from cancer was increased 9 percent in cases of very severe depression or anxiety, the investigators found. Lower levels of psychological distress were not associated with increased risk of cancer death.
An individual’s actual risk of death remains small, however, and people shouldn’t assume they are doomed to an early death if they suffer from a psychological disorder.
Dr. Glyn Lewis, a professor of psychiatric epidemiology at the University of Bristol in England and author of an accompanying journal editorial, said evidence linking stress to heart disease continues to mount.
“If we can reduce the psychological impact, then this should reduce the biological response,” he said. But how to accomplish that remains a puzzle.
A type of psychological treatment called cognitive behavioral therapy is designed to help people change the way they respond to potentially stressful events, Lewis said. Cognitive behavioral therapy teaches
patients to change their thinking about situations and to react less emotionally.
“This might help people with [clinical] depression, but there is no evidence that this might help the much larger numbers of people who have low-level symptoms that are below the diagnostic threshold for depression,” he said.
While antidepressants might improve depression, previous studies have linked their use to greater risk of heart disease, according to background research in the study. About 7.5 percent of United Kingdom residents have depression and anxiety disorders, Lewis said.
Changing this stress-disease dynamic might also involve keeping common risk factors for cardiovascular disease in check, another expert said.
Dr. Gregg Fonarow, a professor of cardiovascular medicine at the University of California, Los Angeles, said many studies have demonstrated an association between depression and anxiety and cardiovascular events, cardiovascular deaths and all-cause mortality.
But so far, no evidence has shown that treating depression or anxiety reduces the risk of heart disease, Fonarow said.
Many different mechanisms may connect psychological distress to cardiovascular disease, including increased sympathetic nervous system activity, stress hormones such as cortisol, chronic inflammation, unhealthy lifestyle factors and inattention to early symptoms, he said.
“For people with depression or anxiety, focusing on proven cardiovascular risk factor interventions, including maintaining healthy blood pressure, body weight, cholesterol levels, engaging in regular exercise and not smoking, may represent the best course of action to lower their cardiovascular risk,” he advised.
