High levels of depression are costing the country almost £11bn a year in lost earnings, in demands on the health service and in prescribing drugs to tackle the problem.

The extent of the economic damage caused by the illness emerged as new figures showed that the use of anti-depressants and sleeping pills is soaring. Last night charities said the economic turmoil, increased job insecurity and mounting unemployment have contributed to growing levels of depression over the past three years.

According to research by the House of Commons, people unable to work because of depression lose £8.97bn of potential earnings per year. The loss of earnings from people who commit suicide is estimated at a further £1.47bn. The cost to the NHS of treating depression is put at more than £520m a year. This comprises £237m for hospital care, £230m for antidepressant drugs, £46m for doctors' time and £9m for outpatients' appointments.

The Liberal Democrat MP Jo Swinson, who commissioned the research, said: "Failure to tackle depression hurts us all. It makes a misery of the lives of sufferers, costs the NHS in terms of time and medication and hampers business by forcing some people out of work."

But Ms Swinson, the chair of the All-Party Parliamentary Group on Wellbeing Economics, suggested that "much depression is preventable and treatable". She cited flexible working patterns, which could reduce stress and absenteeism, and backed investment in counselling and therapy.

The breakdown of the statistics suggested that women were nearly four times more likely than men to approach their doctor with the problem.

The NHS Information Centre discloses today that 43.4 million prescriptions for antidepressants were dispensed in 2010-11, a rise of 28 per cent over three years. The use of anti-anxiety medication rose by 8 per cent over the same period, with Diazepam the most widely prescribed drug. Sleeping pill prescriptions went up by 3 per cent to 10.2 million. Across all these groups of drugs, there was a 20 per cent rise in prescription items, with the largest increases recorded in the East Midlands and the North-east.

Emer O'Neill, the chief executive of the charity Depression Alliance, said: "For some people depression just happens, but for others it is triggered by stressful events, for example losing a job, property or bereavement. These uncertain economic times are linked to an increase in the number of people with the illness."

Case study: 'I went to Beachy Head twice to die'

John Lake, 34 , from London, became severely depressed in 2005 while working as an actor, three years after suffering a brain tumour. He was out of work for three years while he recovered with the help of the charity Time To Change. He said: "I found myself at Beachy Head twice, contemplating suicide. The second time I was sectioned and spent a month in hospital. In hospital, I realised how common depression is, and that it's not limited to one segment of society.