The findings of the research team from the Universities of Oxford and Edinburgh are published today in three papers in the journals The Lancet Psychiatry, The Lancet and The Lancet Oncology.

The team analysed data from more than 21,000 patients attending cancer clinics in Scotland and found that major depression is substantially more common in cancer patients than in the general population.

Major depression was most common in patients with lung cancer (13%) and lowest in those with genitourinary cancer (6%). Moreover, nearly three quarters (73%) of depressed cancer patients were not receiving treatment for their depression.

The huge benefit...shows what we can achieve for patients if we take as much care with the treatment of their depression as we do with the treatment of their cancer. Professor Michael Sharpe

To address the problem of inadequate treatment, the researchers evaluated the effectiveness of a new treatment programme called 'Depression Care for People with Cancer' (DCPC) in a randomised trial called SMaRT Oncology-2.

The DCPC treatment programme is delivered by a team of specially trained cancer nurses and psychiatrists working in collaboration with the patient's cancer team and general practitioner, and is given as part of cancer care. It is a systematic treatment programme that includes both antidepressants and psychological therapy.

The trial involved 500 adults with major depression and a cancer with a good prognosis (they had a predicted survival of more than 12 months), and compared DCPC with usual care.

The researchers found that the Depression Care for People with Cancer programme was strikingly more effective at reducing depression.

Professor Michael Sharpe from the Department of Psychiatry at the University of Oxford said: 'The huge benefit that DCPC delivers for patients with cancer and depression shows what we can achieve for patients if we take as much care with the treatment of their depression as we do with the treatment of their cancer.'

At 6 months, 62% of the patients who received DCPC responded to treatment (at least a 50% reduction in the severity of their depression) compared with only 17% of those who received usual care. This benefit was sustained at 12 months.

DCPC also improved anxiety, pain, fatigue, functioning, and overall quality of life. Moreover, the cost of providing DCPC was modest (£613 per patient) making it a cost-effective way to improve cancer patients' quality of life.

To see if patients having a cancer with poor prognosis could also benefit from this approach, the researchers carried out the SMaRT Oncology-3 randomised trial. This tested a version of DCPC that was adapted for patients with lung cancer, a typically poor prognosis cancer.

The trial, involving 142 patients with lung cancer and major depression, found that those who received the lung cancer version of DCPC had a significantly greater improvement in depression than those who received usual care during 32 weeks of follow-up. The lung cancer-specific version of DCPC also improved anxiety, functioning, and quality of life.

Dr Jane Walker from the University of Oxford and Sobell House Hospice in Oxford said: 'Patients with lung cancer often have a poor prognosis. If they also have major depression that can blight the time they have left to live. This trial shows that we can effectively treat depression in patients with poor prognosis cancers like lung cancer and really improve patients' lives.'