Latest treatment options for Alzheimer's disease, Parkinson's disease dementia and dementia with Lewy bodies.

INTRODUCTION: Alzheimer's disease (AD), Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB) together account for the vast majority of individuals with dementia. Approximately 35 million people worldwide are affected with this condition, and despite decades of research, effective therapies that slow or reverse disease progression have not yet been developed. The recent failure of several large-scale clinical trials is beginning to challenge the magnitude of focus on amyloid-related therapies for AD, and newer drug targets that have shown promise in the laboratory are being investigated in clinical trials. AREAS COVERED: This review summarises the current understanding of the underlying biology of AD, PDD and DLB and outlines the most recent drug candidates in advanced clinical trials. EXPERT OPINION: The lack of success in drug discovery for disease-modifying therapies for AD, PDD and DLB can be attributed to limitations in the design of clinical trials and the narrow focus of molecular targets for treatment. New avenues for drug discovery including repositioning and novel target identification may now provide opportunities for success, provided a critical mass of clinical trials is achieved through increased investment.