Management of chronic noncancer pain in depressed patients.

Many patients with chronic noncancer pain present with comorbid depression, which can greatly complicate the treatment of pain. Chronic pain and depression each increase the risk of licit and illicit substance abuse, including the abuse of opioids, and of suicide. Patients attempting suicide may overdose on opioids, which are commonly perceived as potentially harmful, or acetaminophen, an agent that is believed to be safe but is actually the leading cause of liver failure in the United States. Opioids, acetaminophen, and nonsteroidal anti-inflammatory drugs (NSAIDs) have the potential to interact with antidepressants, and their adverse effects may be exacerbated by alcohol use, which is also common in patients with depression. Topical NSAIDs, capsaicin, and lidocaine provide effective analgesia for several pain conditions. These agents limit systemic drug exposure, reducing the risk of systemic adverse events without risk of accidental or deliberate overdose. However, use of topical agents is generally limited to localized pain syndromes and therefore does not substantially eliminate the need for systemic analgesics in those patients with diffuse persistent pain, central sensitization, and opioid-responsive pain. This review will discuss the challenges associated with treating chronic pain in depressed patients and will provide recommendations for optimizing treatment.