Comorbid insomnia: current directions and future challenges.

Insomnia is a leading cause of absenteeism, presenteeism (lost productivity when employees are at work), accidents, and errors in the workplace. Overall direct and indirect costs exceed $30 billion annually. A significant portion of these costs are attributable to patients with comorbid insomnia, making these conditions a significant clinical public health issue. These comorbid conditions include mood and anxiety disorders; chronic pain; respiratory, urinary, and neurologic conditions; diabetes; and cardiovascular diseases. Traditional treatment for insomnia with comorbid conditions has focused on treating the comorbid condition with the expectation that the insomnia will resolve. Recent studies, however, suggest this approach is not the most appropriate. Instead, treating both conditions simultaneously may improve the outcomes for each.