People with symptoms of anxiety or depression – known as psychological distress – have a higher risk of death from several major causes, according to a study published online today by the BMJ.
Even people with lower levels of distress who would not usually come to the attention of mental health services were found to have a 20% higher risk of mortality after adjusting for age and sex, said the authors of the UK study.
It is estimated that around a quarter of the general population suffer from these minor symptoms of anxiety and depression.
Previous studies investigating the association between psychological distress and mortality have been small and unable to reliably measure thresholds of risk.
In the new study, partially funded by the Wellcome Trust, a team of researchers from University College London and the University of Edinburgh analysed data from 68,222 adults aged 35 years and over who took part in the Health Survey for England from 1994 to 2004.
The researchers’ aim was to measure the role of psychological distress as a risk factor for death from all causes, cardiovascular disease, cancer and external causes occurring over an eight-year period.
They measured psychological distress using a recognised scale ranging from no symptoms to severe symptoms of stress and anxiety. Death certificates were used to record cause of death.
Over the eight years, there were 8,365 deaths overall and of those, 3,382 involved cardiovascular disease, 2,382 from external causes.
The authors found that psychological distress was a risk factor for death from all causes, cardiovascular disease, and external causes—the greater the distress, the higher the risk.
Dr Tom Russ, lead author and clinical research fellow for Alzheimer Scotland Dementia Research Centre at the University of Edinburgh, said: “Even people with low distress scores were at an increased risk of death.
“Currently these people—a quarter of the adult population—are unlikely to come to the attention of mental health services due to these symptoms and may not be receiving treatment.”
Dr David Batty, senior author, added: “These associations also remained after taking into account other factors such as weight, exercise, smoking, alcohol consumption and diabetes. Therefore this increased mortality is not simply the result of people with higher levels of psychological distress smoking or drinking more, or taking less exercise.”
The study is the largest so far to show a dose-response relation between psychological distress and mortality and has potentially important implications for treatment, say the authors.
Dr Russ concluded: “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 modify this increased risk of death.”