One in five employees suffers from a mental illness, such as depression or anxiety, and many are struggling to cope, according to a new report released Monday by the Organization for Economic Co-operation and Development, an international economic organization of 34 countries including the U.S.

Mental illness is a growing problem in society and is increasingly affecting productivity and well-being in the workplace.

Three in four workers with a mental disorder report reduced productivity at work, compared to one in four workers without a mental disorder. Work absences are also much more frequent for workers with mental illness, and about 30 percent to 50 percent of all new disability benefit claims in OECD countries are now attributed to mental ill health.

People with a mental disorder are two to three times as likely to be unemployed as people with no disorders. This gap represents a major loss to the economy, as well as for the individuals and their families.

The share of workers exposed to work-related stress, or job strain, has increased in the past decade all across the OECD. And in the current economic climate, more and more people are worried about their job security, the report said.

Today, almost 50 percent of those with a severe mental disorder and over 70 percent of those with a moderate mental disorder do not receive any treatment for their illness, according to the OECD.

Most common mental disorders can get better, and the employment chances be improved, with adequate treatment. But health systems in most countries are narrowly focused on treating people with severe disorders, such as schizophrenia, who make up only one-fourth of sufferers.

OECD urges policymakers to look for new solutions and take more common disorders more seriously.