MAYWOOD, Ill. - There is a high rate of depression among patients with hepatitis C, but a standard treatment for the disease includes a drug, interferon, that can cause depression.In a review article, researchers tackle the complexities of diagnosing and managing depression before and after initiating treatment with interferon.Dr. Murali S. Rao of Loyola University Medical Center is a co-author of the study, published in the International Journal of Interferon, Cytokine and Mediator Research.This article was first published at www.newswise.com"Depression is a relatively frequent and potentially serious complication of interferon therapy for hepatitis C virus infection," the researchers write. "However, other etiologies [causes] of depression may coexist and have to be carefully excluded."Hepatitis C is the most common chronic blood-borne infection in the United States. At least 4 million people have been exposed and 3.2 million are chronic carriers.The drugs ribavirin and pegylated interferon are mainstay treatments. Pegylated interferon can help relieve muscle and joint pain and reduce the disabling fatigue. But a well-established side effect of interferon is depression of variable severity -- including suicidal thoughts. The prevalence of depression among hepatitis C patients receiving interferon has been reported to be between 10 percent and 40 percent, depending on the screening method used.One of the main concerns in treating hepatitis C patients is the risk of suicide, especially since many patients already are depressed before beginning therapy. Patients who have a personal or family history of a serious mood disorder, depression, suicidal thoughts or suicide attempts "should be carefully interviewed and referred to a specialist for assessment of suicide risk and treatment of the underlying disorder before treatment with interferon can be considered," the authors write. The SSRI class of antidepressants, such as citalopram (brand name, Celexa), have been shown to be effective in treating depression in hepatitis patients treated with interferon. The related SNRI class of antidepressants, such as milnacipran (Savella), also can reduce depressive symptoms in patients taking interferon. But there have been conflicting results in studies on whether giving antidepressants before starting interferon can prevent depression, the authors write.Interferon can affect the level of serotonin, a compound that is responsible in part for regulating mood and other brain functions. This may be the reason why antidepressants don't always work in patients who take interferon, the authors write.Rao, an expert on depression, is chair of the Department of Psychiatry and Behavioral Neurosciences of Loyola University Chicago Stritch School of Medicine. Other authors are Dr. Haris Papafragkakis (first author) and Dr. Paul Martin of the University of Miami, Dr. Martin Moehlen of Tulane University and Dr. Sonu Dhillon of St. Francis Medical Center in Peoria, Ill.