Depression is common in Parkinson's disease (PD), and its identification and treatment are critically important in disease management. Despite depression's high prevalence and major impact on patient quality of life, questions remain regarding its epidemiology and preferred treatment. The authors of this paper summarize available information on the epidemiology of depression in PD, review treatment options, and discuss possible interactions between antidepressants and other agents. This information may help guide clinical treatment and define the need for further studies.