Common mental illnesses such as depression and anxiety are lowering workplace productivity, a new report states. To make matters worse, workers’ efficiency may continue to decline for the foreseeable future because stress – prevalent in times of job insecurity – can trigger symptoms in those with mental illness, officials say.

One in five workers suffers from mental health issues, which results in an increased number of sick days, said the Organization for Economic Cooperation and Development (OECD). In addition, the international agency says, these illnesses account for 30 to 50 percent of disability claims.

By 2020, it is estimated that depression alone will be the second leading contributor to disease for all age groups, according to the World Health Organization.

“Most common mental disorders can get better, and the employment chances be improved, with adequate treatment,” the OECD said.

However, it is estimated that more than 70 percent of people with moderate mental illness and 50 percent with severe cases get no treatment at all.