Major depression is a persistent sadness or “feeling blue” that interferes with daily activities. Common symptoms are lack of energy, change in sleep or appetite, loss of interest in activities, and thoughts of worthlessness or guilt. Sometimes the condition goes away on its own, but most people with major depression need treatment with counseling or medication (or both) to speed recovery. Treating depression can be difficult. Antidepressant drug therapy may relieve some but not all symptoms, and it may cause troublesome adverse effects. If an antidepressant drug does not work well, doctors sometimes switch to another drug or add a second drug. Risperidone (Risperdal, Janssen, Titusville, New Jersey) is an atypical antipsychotic drug. It is sometimes used to treat depression that is resistant to other therapies. We do not know whether adding risperidone to antidepressant therapy will help patients with persistent symptoms.