A large study of English households finds that people who experience symptoms of psychological distress like anxiety, depression, or even minor mental health problems, have a lower life expectancy than people who do not.

Since the link remained when they adjusted for lifestyle factors, the researchers say the effect is more likely due to biological changes resulting from psychological distress rather than because people with poor mental health have less healthy lifestyles.

The Wellcome Trust funded study is expected to trigger more research into how doctors treat people with even mild mental psychological problems.

The team, from University College London (UCL) and the University of Edinburgh, write about their work in the 31 July issue of BMJ.

Senior author David Batty, from the Department of Epidemiology and Public Health at UCL, told the press:

“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.”

Previous research into the association between mental health and life expectancy has consisted mainly of small studies with samples that are not big enough to produce statistically robust results.

For the BMJ study, the largest to address this problem to date, Batty and colleagues analyzed data from more than 68,000 people aged 35 and older who took part in the Health Survey for England from 1994 to 2004.

As part of the survey, the participants had filled in the General Health Questionnaire GHQ-12, a recognized measure that assesses mental health on a 12-item scale. The range extends from no symptoms to severe symptoms of depression and anxiety.

The participants were followed for an average of 8 years. From National Health Service mortality data, the researchers were able to determine which participants died over the study period and what from, and correlate this information with the mental health scores.

The results showed that participants who experienced symptoms of anxiety or depression had a lower life expectancy than those who did not.

Even having minor symptoms of psychological distress, which applied to about a quarter of the participants in this study, was linked to a higher risk of premature death from several major causes, including heart disease.

People with minor symptoms of depression or anxiety often don’t seek medical help, and the researchers say their findings could have implications for how these minor mental health issues are treated by the health system.

It could be that treating these minor symptoms could reduce the increased risk of premature death.

John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, said the findings show we need to make sure people with mental health problems can access the care and advice they need.

“People with mental health problems are among the most vulnerable in society,” said Williams.

Written by Catharine Paddock PhD