US workers who have been diagnosed with depression cost their employers billions of dollars annually with their absenteeism, new data shows.According to the Gallup-Healthways Well-Being Index data, the missed work days by depressed employees costs US companies over $23 billion in lost productivity annually. Those depressed employees miss an estimated 68 million additional days of work each year than their counterparts who have not been depressed, the survey found. The enormous cost of absenteeism does not include other economic costs linked with depression, including healthcare expenses, workers' compensation, and turnover, among others. Gallup found that 12 percent of all American workers say they have been diagnosed with depression at some point in their lifetime. However, part-time workers are much more likely to report having ever been diagnosed with depression, at 16.6%. According to survey from the American Psychological Association, one-third of workers in the US experience work related chronic stress. The main reasons for the chronic stress were low pay and not enough opportunity for advancement. Prolonged depression and stress have harmful effects on humans, which include causing pain, insomnia, suicidal thoughts and heart disease. The rise in workers' dissatisfaction is partly due to the struggling US economy and weak wage growth. But worker dissatisfaction has been on the rise for more than two decades and many people are having difficulty finding suitable jobs.