People with mental health problems have a lower life expectancy, according to a large-scale population based study published July 31 in the British Medical Journal. The findings may prompt further research into the way doctors treat patients with even mild psychological problems.

A team of researchers from UCL (University College London) and the University of Edinburgh analysed data from over 68,000 adults aged 35 years and over who took part in the Health Survey for England from 1994 to 2004.

Participants in the study had been evaluated for mental health problems using a recognised scale ranging from no symptoms to severe symptoms of depression and anxiety. The team then looked to see whether people who reported these symptoms during the study were more likely to have died over an 8 year period. They also examined whether there was an association with death from cardiovascular disease, cancer or from external causes of death.

Their results reveal that people who experienced symptoms of anxiety or depression had a lower life expectancy than those without any such symptoms. Even people with minor symptoms of mental health problems seemed to have a higher risk of death from several major causes, including cardiovascular disease.

Dr David Batty, a Wellcome Trust research fellow in the Department of Epidemiology & Public Health at UCL and senior author on the study, explains: "These associations also remained after we did our best to take into account other factors such as weight, exercise, smoking, alcohol consumption and diabetes. Therefore this increased mortality is not simply due to people with higher levels of psychological distress having poorer health behaviours."

There is a possibility that mental health problems may be associated with biological changes in the body that increase the risk of diseases such as heart disease.

In this study, approximately a quarter of people suffered from minor symptoms of anxiety and depression, however, these patients do not usually come to the attention of mental health services. The authors say that their findings could have implications for the way minor mental health problems are treated.

Dr Tom Russ, Alzheimer Scotland clinical research fellow at the University of Edinburgh, said: "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."

Previous studies investigating the association between symptoms of mental health and life expectancy have been small and unable to reliably measure thresholds of risk. This is the largest study to address the problem to date.

John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, said: "People with mental health problems are among the most vulnerable in society. This study highlights the need to ensure they have access to appropriate health care and advice so that they can take steps to improve the outcome of their illness."

Understanding the brain and finding improved approaches for treating brain and mental health disorders is one of the Wellcome Trust's five strategic research challenges.