Mental health problems affect many working people, according to the February 2010 issue of the Harvard Mental Health Letter . Yet they often escape notice because these disorders tend to be hidden on the job. Mood symptoms, for example, can masquerade as physical problems such as irritability and sleep disturbances. Efforts to identify and treat mental health problems not only improve employee health, but also increase workplace productivity.

About one in five working-aged Americans experiences symptoms of a mental health disorder in any given month, according to theHarvard Mental Health Letter. Depression, anxiety, and addiction problems are among the most common.

Because of the stigma associated with psychiatric disorders, employees may be reluctant to seek treatment — especially in the current economic climate, when they are concerned about losing their jobs. At the same time, managers may want to help but might not know how. As a result, mental health problems in working Americans often go undetected and untreated for years.

Most of the research on the costs and benefits of mental health treatment in the workplace has been done on depression. This work shows that when depression is adequately treated, companies reduce job-related accidents, sick days, and employee turnover, and improve the number of hours worked and employee productivity.

Treating mental health problems in the workplace isn't a quick fix, says theHarvard Mental Health Letter. But over the long term, it is a sound strategy. Money spent on mental health care represents an investment that will pay off — not only in healthier employees, but also for the company’s financial health, notes Dr. Michael Miller, editor in chief of theHarvard Mental Health Letter