LORELAI: Now these erasers are on lithium so they may seem cheerful but we actually caught them trying to shove themselves in the pencil sharpener earlier.
Lithium (Li) is a chemical element; the lightest metal and the lightest solid element. Lithium salts are used as a psychiatric medication to treat major depressive disorders and bipolar disorders; it is not understood how they work to stabilise mood, but they reduce the incidence of suicide.
The Annotated Gilmore Girls 