A number of interesting studies on lithium have turned up in recent years, such as its possible association with longevity in humans. Here researchers are testing it against Parkinson's disease: "A two-year study of the effects of lithium treatment on Parkinson's disease in mice has given researchers at the Buck Institute for Research on Aging hope that the drug may halt brain damage in humans with the degenerative disorder. The research found that lithium, the Food and Drug Administration-approved drug most commonly used to treat bipolar disorder, 'profoundly prevents the aggregation of toxic proteins and cell loss associated with Parkinson's disease' in mice. ... In the last couple of years, there's been kind of a growing body of data that suggests that lithium could have some neuroprotective effects ... Other diseases lithium treatment may benefit include Alzheimer's, Huntington's and Lou Gehrig's. ... In addition, recent studies have suggested that the naturally occurring substance may extend life span. ... The group is now doing preclinical research on dose level and other issues and hopes to raise funds for a clinical trial with humans as soon as possible. ... Nonetheless, it is too early to draw conclusions, [as] medications that appear to halt Parkinson's in animals don't necessarily work the same way in humans. Lithium's potential for toxicity is also of concern, particularly because Parkinson's patients are often quite fragile, he said. In at least two known cases, toxic levels of the drug have actually caused Parkinson's."