Mild mental health problems that would not normally call for medical attention have been linked to an increased risk of death.
Researchers from University College London and the University of Edinburgh have found that people with symptoms of anxiety and depression, which professionals commonly refer to as psychological distress, are more vulnerable to serious health complications such as strokes and heart disease.
Furthermore, the researchers - who published their findings on BMJ.com - found that people suffering from even the smallest levels of stress and distress may pay less attention to their health, and engage in unhealthy behaviour which can have grave long-term consequences.
The research was based on analysis of over 68,000 adults aged 35 and over, who took part in the Health Survey for England from 1994 to 2004.
The researchers aimed to measure the role of psychological distress as a risk factor for cancer, cardiovascular disease and external causes of death, over an eight-year period.
"We found that psychological distress was a risk factor for death from all causes, [including both] cardiovascular disease and external causes. The greater the distress, the higher the risk," said lead author Dr Tom Russ.
"However, 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."
Senior author Dr David Batty 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 authors suggest that the study findings have important implications for treatment.
"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," Russ concluded.