The diagnosis and treatment of depression in Parkinson's disease.

Depression is common in Parkinson's disease (PD) and associated with considerable morbidity, including a worsening of motor symptoms and measures of quality of life. Therefore, patients with PD should be routinely screened for depressive symptoms with rating scales such as the Geriatric Depression Scale. Patients meeting criteria should be treated using established algorithms for the management of depression and associated symptoms such as insomnia, anxiety, psychosis, and mania. The algorithm outlined in this paper describes the importance of maintaining an adequate dose of medication over a medication trial that can last up to 12 weeks. To optimally monitor patients' progress, clinicians should also consider using rating scales that measure depression severity, such as the Montgomery-Asberg Depression Rating Scale and Beck Depression Inventory.