Societal burden and persisting unmet needs of Parkinson's disease

Abstract

Parkinson's disease (PD) imposes a serious burden on patients, carers, families, healthcare providers and health authorities globally. PD affects 0.3% of people in the developed world and its prevalence is increasing with an estimated 2.1 million people with PD worldwide in 1990 rising to 6.1 million in 2016. This increase has been driven by growing elderly populations and other, as yet, unknown factors. The cost of PD has been estimated at $14.4 billion/year in the USA and that is predicted to double by 2040. PD continues to have manifold unmet needs in terms of understanding pathophysiology, early detection, reliable biochemical and/or genetic biomarkers, diagnosis, improved PD assessment scales, predicting trajectory, and effective treatments for both motor and non-motor symptoms. Levodopa continues to be the most effective drug treatment for PD; in recent decades, many promising improved drug therapies have failed to show efficacy in clinical trials. The treatments available mainly address motor symptoms but not the non-motor symptoms which often start earlier and are overall more detrimental to patient well-being and quality of life. Holistic approaches with multiple modes of action are needed in the development of new treatments rather than using single target approaches such as drugs that only affect the dopaminergic system. Despite this apparently bleak overall picture, there are grounds for optimism as knowledge of PD pathophysiology is increasing, potential new therapeutic targets have been identified and novel treatments are in development. Earlier diagnosis, treating non-motor symptoms as they appear and the ongoing development of drugs to slow or alter disease progression have the potential to improve the outlook for people with PD at present or in the near future.