Cymbalta is a medication that is used to treat depression and anxiety in adults, as well as generalized anxiety disorder (GAD) in adults and children who are at least 7 years old. It is also used to treat nerve pain caused by diabetes (diabetic neuropathy), chronic muscle or joint pain (such as low back pain and osteoarthritis pain), and fibromyalgia (a chronic pain disorder) in adults and children at least 13 years old. Cymbalta belongs to a class of medications called selective serotonin and norepinephrine reuptake inhibitors (SNRIs), which work by increasing the amounts of serotonin and norepinephrine, natural substances in the brain that help maintain mental balance and stop the movement of pain signals in the brain. It is important to note that Cymbalta can interact with other medications and should not be taken with monoamine oxidase inhibitors (MAOIs) or certain other drugs. It is also important to talk to a doctor about any other medications or supplements being taken before starting Cymbalta.