Parkinson's Disease Drug Development Since 1999: A Story of Repurposing and Relative Success.

Background: A global overview of drug development programs in Parkinson's disease over the last few decades is lacking, while such programs are challenging given the multifaceted and heterogeneous nature of the disease.

Objective: To indirectly assess drug development programs in Parkinson's disease, exploring some factors associated with compound attrition at different trial phases.

Methods: We assessed all Parkinson's disease trials in the WHO trials portal, from inception (1999) to September 2019.

Risk of Developing Parkinson Disease in Bipolar Disorder: A Systematic Review and Meta-analysis.

Importance: Parkinson disease (PD) manifests by motor and nonmotor symptoms, which may be preceded by mood disorders by more than a decade. Bipolar disorder (BD) is characterized by cyclic episodes of depression and mania. It is also suggested that dopamine might be relevant in the pathophysiology of BD.