Depression and anxiety could raise risk of death from cancer
British researchers have found that people who are frequently depressed or anxious may run a higher risk of dying from certain types of cancer.
The medical records of more than 160,000 adults in England and Wales indicated that people who described themselves as psychologically distressed were far more likely to succumb to cancer, especially of the pancreas, oesophagus and colon.
The likelihood of dying from leukaemia was also far more elevated among this group, the researchers found.
In a study published in the BMJ medical journal, the scientists were cautious in their conclusions, pointing out that a statistical link does not necessarily signify a cause-and-effect relationship between mood and cancer.
Their findings nevertheless added to the growing body of evidence that mental and physical health do not function on separate planes, and that one can influence the other.
While earlier research had shown that chronic depression and anxiety could help trigger heart disease and stroke, attempts to forge similar links between states of mind and cancer have yielded mixed results.
Four researchers, led by David Batty of University College London, set out to learn more by examining data from 16 long-term studies, covering 163,363 adults.
The participants were monitored for an average of nearly a decade, during which time more than 4,300 of them died of cancer.
Batty and his team studied raw data on psychological distress levels, lifestyle habits and cancer incidence, searching in particular for evidence of links between stress and cancers related to hormonal changes or lifestyle.
It has already been established that depression can disrupt hormonal balance to the extent of boosting natural cortisone concentrations and inhibiting DNA repair mechanisms – both of which weaken defences to cancer.
It is also well known that emotionally distressed people are more likely to smoke, drink and become obese – all of which are associated with a higher cancer risk.
But regardless of lifestyle, the researchers found that people who described themselves as depressed were more than twice as likely to succumb to pancreatic or oesophageal cancer, and nearly twice as likely to die of colon cancer. The rate for leukaemia was even higher.
The scientists could not discount the possibility that depression could be a result, rather than the cause of cancer, however.
“Distress might be a consequence of the early stages of the malignancy rather than a potential predictor,” they said.
Batty noted that further research was needed to confirm the link and tease out the causal connections.