m e t h o d s : This review discusses the pharmacologic activity and poten­ tial effectiveness of lithium in the context of Alzheimer disease (AD) and Parkinson's disease (PD), the 2 most prominent neurodegenerative dis­ orders in the United States. The toxicides of lithium, including lithiuminduced extrapyramidal symptoms (LL-EPS) and cognitive impairments at therapeutic blood levels, are disc...