Depression in Parkinson’s disease

Depressive disturbances are common in patients with Parkinson’s disease (PD) and have a significant negative impact on the patient’s quality of life, activities of daily living and cognitive performance. Depression is present in about 35% of the PD patients and may precede the diagnosis of PD. The core symptoms of depression are also inherent to PD even in the absence of depression, making effective diagnosis of depression in this patient group challenging. The pathophysiology of depression in PD remains unknown, but changes in brain structure and function, inflammatory and neurotrophic factors as well as altered neurotransmitters levels are thought to contribute to its development. Specifically, changes in monoamine systems might be associated with the incidence of depression in patients with PD. In this chapter, we review studies on the clinical presentation, diagnosis, etiology, and the management and treatment of depression in individuals with PD.