Depression can hurt physically.

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­"Peanuts" character Charlie Brown was way ahead of doctors today in understanding that mental and physical pain were connected. "This is my depressed stance," he once said. "When you're depressed, it makes a lot of difference how you stand" [source: Applegate et al.]. Charlie Brown, though just a small boy, understood the mind-body connection. He discerned that mood could affect stance and vice versa.

Physical pain and depression are interlinked because often one causes the other. Approximately 30 percent of those who experience chronic pain eventually suffer from clinical depression, and 75 percent of depression patients seek treatment from a doctor because of a physical symptom such as pain [source: National Pain Foundation].

Scientists believe that mood and pain may be regulated by the same neurochemicals, so obviously, the ideal treatment for a person experiencing both conditions would address both problems. The most well-known drug that serves as both an antidepressant and a pain management tool is Cymbalta. Cymbalta, manufactured by Eli Lilly, is the brand name for the drug duloxetine. Since the U.S. Food and Drug Administration (FDA) approved Cymbalta as a treatment for depression in August 2004, more than 9 million people in the United States have been treated with the drug [source: Cymbalta].

Currently, Cymbalta has four major uses. It's primarily used to treat major depressive disorder, but it may also be prescribed for general anxiety disorder, nerve pain associated with diabetes and pain associated with fibromyalgia. How can one drug do so much? Are there any side effects? Let's take a closer look at Cymbalta.