LONDON, Nov. 20 (UPI) -- British and Norwegian researchers said depression is as big of a mortality risk factor as smoking.
However, the study found, unlike depression alone, a combination of depression and anxiety lowers mortality.
"One of the main messages from this research is that 'a little anxiety may be good for you,'" Dr. Robert Stewart of Kings College London said in a statement.
Possible reasons may that be those with anxiety may be more willing to ask for help and doctors may be more likely to investigate further to calm anxieties, the researchers said.
The researchers tracked 60,000 people for four years. The mortality risk was increased in a similar extent in people who were depressed as in people who were smokers.
"It appears that we're talking about two risk groups here. People with very high levels of anxiety symptoms may be naturally more vulnerable due to stress, for example through the effects stress has on cardiovascular outcomes," Stewart said.
"On the other hand, people who score very low on anxiety measures, i.e. those who deny any symptoms at all, may be people who also tend not to seek help for physical conditions, or they may be people who tend to take risks. This would explain the higher mortality."
The findings are published in the British Journal of Psychiatry.