Stress in the workplace is a severe and growing problem that led 34 percent of American employees to consider quitting their jobs in 1990, according to a survey.

"Employee Burnout: America's Newest Epidemic," a copyright study by Northwestern National Life Insurance Co., indicates 46 percent of American workers find their jobs highly stressful.That is more than double the finding in a 1985 study by the National Health Interview Study in which 20 percent said they experienced a high level of stress.

The study had a margin of error of plus or minus 4 percentage points.

Stress levels were heightened by the recession, with 40 percent of workers saying they felt more pressure to prove their value to their employer because of the sluggish economy.

Any major change in workplace staffing - often a result of recession - is likely to accelerate stress, the research indicated.

Significant burnout occurred in companies that had substantially cut employee benefits, changed ownership, required frequent overtime or reduced the work force, Northwestern National said.

"The most important finding is that workplace stress is so pervasive, that change in the workplace is accelerating burnout," said Peggy Lawless, research analyst in the employee benefits division of Northwestern National, an insurer based in Minneapolis.

The study says workplace stress is costly to American business in terms of lower productivity, greater worker turnover, higher absenteeism and more frequent health problems than recognized.