In the red and feeling blue ...

MR Micawber put it in a nutshell more than 150 years ago. 'Annual income twenty pounds,' declared Charles Dickens's fictional spendthrift, 'annual expenditure twenty pounds ought and six, result: misery.'

Now a high-powered research effort is under way to find out just how right he was.

Britain's biggest debt counselling service, with help from the World Health Organisation and the Office for National Statistics, is to investigate the link between heavy indebtedness and clinical depression.

'There is some evidence already that half of those with debt problems have suffered from clinical depression,' said the Consumer Credit Counselling Service. 'That compares with a rate of just 14% in the population as a whole.'

Consumer credit is rising at an annual rate of about £113bn and 35,898 people were declared bankrupt in England and Wales in 2004, up from 28,021 in 2003. Meanwhile, the cost to the National Health Service of anti-depressant drugs is estimated at £400m a year.

The CCCS is taking 250,000 calls a year from borrowers with debt problems. Of these, 100,000 go on to be interviewed in greater depth, and it is at this stage that a sample will be asked to take part in the new survey.

The CCCS said: 'We will survey a minimum of 5,000 people and a maximum of up to 15,000. We had hoped to have completed the work in seven months, but that may be on the optimistic side.'

Not only does the service hope the research will contribute to medical understanding of the relationship between debt and depression, it also wants to use the results to improve the training of its counsellors.