Image copyright SPL Image caption Some studies suggest depression can affect the chances of surviving cancer

Three-quarters of cancer patients who are clinically depressed do not get the psychological therapy they need, according to research in the Lancet.

This "huge unmet need" is partly due to a focus on physical symptoms at the expense of good mental healthcare, researchers say.

They argue depression is often overlooked but could be treated at a fraction of the cost of cancer drugs.

Charities say the current situation is "heartbreaking".

It is heartbreaking to think cancer patients who are already dealing with the toughest fight of their lives are also struggling with depression, without adequate support Jacqui Graves, Macmillan Cancer Support

'Persistent sadness'

People often wrongly assume that major depression is part of a natural reaction to cancer - but this is much more than transient sadness, the Edinburgh and Oxford university researchers say.

Their report suggests a new nurse-led treatment could help thousands of people.

In a series of studies they analysed data on 21,000 cancer patients living in Scotland.

They found 6% to 13% of people had clinical depression, compared with just 2% of the general population at any time.

Media playback is unsupported on your device Media caption Cancer survivor Sonia Wilson said cancer made her feel "like a burden to society"

Sufferers of major depression feel persistently low, may find it difficult to sleep and have poor appetites.

But researchers found 75% of people reporting these symptoms were not receiving treatment, partly because they did not consider seeking help and professionals did not pick up on their illness.

The reports also show that, even when given a diagnosis and standard NHS treatment, the majority did not feel better.

Scientists say a new nurse-led approach designed specifically for patients with cancer can substantially reduce depressive symptoms.

In their study of about 500 patients, the therapy halved the depression scores of more than 60%.

Patients reported they were less anxious, less fatigued and experienced less pain.

Only 17% of those who had standard NHS care had similar results.

Image copyright Thinkstock Image caption Some 13% of people with lung cancer reported symptoms suggestive of major depression

'Profound impact'

In contrast the new intensive, tailored approach is delivered by a trained cancer nurse and involves the wider medical team.

It includes:

antidepressant drugs

encouraging patients to become as active as they can be

problem-solving therapy

Researchers argue that if their programme were rolled out widely it could improve the quality of life for thousands of people.

Their final paper suggests the therapy improves quality of life, regardless of how good a patient's prognosis is.

Dr Stefan Symeonides, of the University of Edinburgh, said: "Day-to-day oncologists like myself see the profound impact depression can have on a patient with cancer."

He added: " [This is] a huge area of unmet need missed by current practice."

Researchers say the therapy costs around £600 per patient.

Jacqui Graves, of the Macmillan Cancer Support charity, said: "It is heart-breaking to think cancer patients who are already dealing with the toughest fight of their lives are also struggling with depression, without adequate support.

"Anyone experiencing depression should get in touch with their GP."