Lithium is a remarkable drug with a fascinating history. Although less popular than other anticonvulsant and atypical antipsychotic mood-stabilizing drugs, lithium is beneficial in bipolar disorder and may be superior to other drugs for treatment-resistant depression and for reducing suicidal behaviors. Various studies have demonstrated that lithium has neuroprotective and neurotrophic cellular effects in the brain, suggesting it may be "brain healthy" for patients with mood disorders and useful for patients with other neurodegenerative disorders. In this article, I describe the history of lithium and review important aspects of its clinical use.