Dr Kevin Holland-Elliott, medical director of occupational health at private healthcare organisation Bupa, says many companies which lose court cases over stress at work are not informing their shareholders of the costs.

"As a result, shareholders are presented with a false picture of corporate performance," he told a major conference on depression, co-sponsored by the World Health Organization.

He believes that bad management is the major cause of stress at work and can triple the cases of employee depression.

Some 20% of the workforce is estimated to suffer from depression at any given time and experts say 27% of all days taken off sick are due to the condition.

Dr Holland-Elliott says stress at work, which he estimates affects four million people in the UK, can also lead to greater risk of personal injury and falling productivity rates.

Bullying

He believes bullying managers and people being put in jobs they are not suited to are key factors in the problem.

"The stress which often leads to serious psychological illness can be caused by a corporate culture which allows and sometimes encourages a bullying management style," he said.

"The solution to these problems are in the hands of management."

He called for simple personality assessments, job rotation and management reviews to tackle the issue.

And he said companies would not be able to avoid the consequences for long since pressure was growing for more protection for employees.

A spokesman for the Trades Union Congress said that, while some companies did report to shareholders on the compensation costs they had to pay out over stress at work, many did not.

The TUC is calling on the government to reform the law so that companies have to inform their shareholders about the cost of all health and safety compensation cases.

Growing problem

The first personal injury court case for stress at work was taken out in 1997 and since then the number has grown rapidly.

Last year, over 450 cases were in progress and figures are expected soon for this year.

But the TUC spokesman said most cases were settled before they get to court.

He hoped the growing number of cases would force an improvement in management strategies and said a small TUC survey last year found 200 health and safety representatives reported that their company already had a stress policy.

The Health and Safety Commission is currently considering whether employers should be prosecuted over stress at work.

It estimates that up to half a million people a year develop stress at work.

One of the problems concerning legislation on the issue is that stress is a difficult condition to diagnose and correct. For example, the commission says some people believe it is difficult to distinguish whether stress is caused by work or events outside the workplace.