One in five workers suffer from a Mental illness such as depression or anxiety and these conditions increasingly affect productivity in the workplace as many struggle to cope, a report by the OECD said on Monday. The Organization for Economic Co-operation and Development found people with mental illness are often off sick from work, and between 30 and 50 percent of all new disability benefit claims in OECD nations are now due to poor mental health. Policymakers need to find new ways to tackle the social and economic problem of mental illness, the report said, as trigger factors, such as stress at work, are likely to increase. "Increasing job insecurity and pressure in today's workplaces could drive a rise in mental health problems in the years ahead," it said. "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." Depression alone is already a major cause of death, disability and economic burden worldwide and the World Health Organization predicts that by 2020 it will be the second leading contributor to the global burden of disease across all ages. Two studies published in September and October found that up to 40 percent of Europeans suffer from mental and neurological illnesses each year, and the annual cost of brain disorders is almost 800 billion euros. The OECD's report, entitled "Sick on the Job? Myths and Realities about Mental Health at Work" found that most people with a mental disorder are in work, with employment rates of between 55 percent and 70 percent -- about 10 to 15 percentage points lower than for people without a disorder. But people with mental illness are two to three times as likely to be unemployed as people with no mental health problems. This gap represents a economic major loss, the report said. "Most common mental disorders can get better, and the employment chances be improved, with adequate treatment," the OECD said. But it said health systems in most countries were narrowly focused on treating people with severe disorders such as schizophrenia, who account for only a quarter of all sufferers. "Taking more common disorders more seriously would boost the chances for people to stay in, or return to, work," the OECD said, adding that around 50 percent of people with severe mental disorders and more than 70 percent of those with moderate illness currently get no treatment at all. The OECD urged policymakers to focus on providing good working conditions which help employees reduce and manage stress, to introduce systematic monitoring of sick leave, and to help employers reduce workplace conflict and avoid unnecessary dismissal caused by mental health problems.