Stress, depression and Parkinson's disease.

In this review, we focus on the relationship among Parkinson's disease (PD), stress and depression. Parkinson's disease patients have a high risk of developing depression, and it is possible that stress contributes to the development of both pathologies. Stress dysfunction may have a role in the etiology of preclinical non-motor symptoms of PD (such as depression) and, later in the course of the disease, may worsen motor symptoms. However, relatively few studies have examined stress or depression and the injured nigrostriatal system. This review discusses the effects of stress on neurodegeneration and depression, and their association with the symptoms and progression of PD.