People who suffer from anxiety may have a higher risk of developing cancer, a study suggests.
There is little evidence psychological problems trigger cancer
The controversial finding is based on a study of more than 60,000 people in Norway.
It will add fuel to the debate over whether psychological factors play a role in determining who may contract cancer.
Scientists are so far divided on the issue, with most saying there is not enough evidence to link stress, depression or anxiety to the disease.
In this latest study, scientists from the University of Bergen followed up 62,591 people who had taken part in a medical survey between 1995 and 1997.
The survey was originally used to draw up a national cancer register in Norway to identify those who had developed cancer or abnormal cells that could turn into cancer.
There have been a number of studies over the years looking to see if psychological problems cause cancer and on balance the answer has to be no
Dr Maggie Watson,
Royal Marsden Hospital
Those involved in the study also took a test to determine if they suffered from anxiety.
According to New Scientist magazine, researchers found that those who scored highly in this test were 25% more likely to have abnormal cells.
However, because of the large number of people involved they were unable to say whether anxiety was a major risk factor.
The survey did not provide information on whether people smoked or led unhealthy lifestyles, which increase the chances of developing cancer.
The findings were presented at a meeting of the American Psychiatric Association in San Francisco, earlier this month.
The meeting also heard details of another study, which suggests that people who suffer from depression may have a higher risk of developing cancer.
Researchers from the State University of Londrina in Brazil compared 40 depressed adults who were not on medication with 34 healthy people.
They found that the patients with depression had poorer immune systems and were less able to fight infections or diseases.
Previous studies have linked poorly-performing immune systems with an increased risk of certain types of cancer tumours.
But Dr Maggie Watson, a consultant psychologist at London's Royal Marsden Hospital, said there was little evidence to suggest psychological problems might trigger cancer.
"There have been a number of studies over the years looking to see if psychological problems cause cancer and on balance the answer has to be no," she told BBC News Online.