Lithium, a simple cationic alkali metal is still the drug of choice in the treatment of bipolar disorder for more than 6 decades. In fact, it has been in medical use since the middle of 19th century, first as an anti-gout and later as a psychoactive agent to treat miscellaneous disorders including bipolar disorder. Shortly after 1950s, lithium became a milestone in the treatment of bipolar disorder. Moreover, this progress was important not only for patients with such a devastating disease but also for patients with other mental disorders. Remarkably, the successful therapy with lithium in bipolar disorder has shown that pharmacotherapy may rescue patients with mental disorders. In recent years, accumulating data indicate that lithium has neuroprotective effects and thus, this knowledge may extend its use in the near future.