Cancer patients suffering from depression could be helped to come to terms with their condition as a new tool is developed helping doctors diagnose the illness.
Clinical depression affects a quarter of advanced cancer patients, according to the University of Liverpool, which launched the detection tool.
However, the researchers warn that it is often misdiagnosed as "appropriate sadness" following the diagnosis of the cancer.
The new testing method is based on a screening system developed for sufferers of post-natal depression.
It is known as the Brief Edinburgh Depression Scale (Beds) and includes a six-step scale to assess the cancer patient's mental condition, including questions on worthlessness, guilt and suicidal thoughts.
"The effects of depression can be as difficult to cope with as the physical symptoms of a terminal illness such as cancer," said Mari Lloyd-Williams, who led the research.
"Patients often feel useless, that they are to blame, and even experience suicidal thoughts during cancer – these are all signs of depression but rarely elicited."
Professor Lloyd-Williams stressed the importance of identifying depression in cancer sufferers to ensure "the patient receives the optimum care possible".