In a study spanning almost a decade, those who experienced high levels of psychological distress were far more likely to die from cancer than those who reported low levels of distress.
The findings, published in the BMJ, add to growing evidence that psychological distress could have some predictive capacity for certain physical conditions.
In a paper about the origins of psychological distress, two experts write that “to some degree, it is necessary for people to function”.
“Without it we may find ourselves in situations that threaten our lives, but which we are unable to do anything about because we fail to register the distress that such situations should engender,” they explained.
“There is a point, though, at which the experience of psychological distress can become the experience of disorder (or illness).”
There is some evidence that psychological distress – such as anxiety or depression – is related to increased rates of cardiovascular disease, but links with different types of cancer have been either unclear or untested.
A team of researchers from University College London, University of Edinburgh and University of Sydney set out to examine if anxiety or depression could act as a predictor of site specific cancer deaths.
They analysed data from 16 studies (13 from England and three from Scotland), which started between 1994 and 2008.
In total, 163,363 men and women aged 16 or over, who didn’t have cancer at the start of the study, were included.
Psychological distress scores were measured using a general health questionnaire and participants were monitored for an average of nine and a half years. During this time, there were 4,353 deaths from cancer.
Several factors that could have influenced the results were taken into account, including age, sex, education, socioeconomic status, BMI, smoking and alcohol intake.
“After statistical control for these factors, the results show that compared with people in the least distressed group, death rates in the most distressed group were consistently higher for cancer of the bowel, prostate, pancreas, and oesophagus and for leukaemia,” said lead author, Dr David Batty from University College London.
He concluded: “Our findings contribute to the evidence that poor mental health might have some predictive capacity for certain physical diseases but we are a long way off from knowing if these relationships are truly causal.”
Stephen Buckley, head of information at Mind, said: “Anxiety and depression are significant health problems regardless of links to other illnesses.
“We welcome this new piece of research which can help us to better understand the links between mental and physical health.”
The study’s authors note that the findings are purely observational, so no firm conclusions about cause and effect can be drawn from it.