Stepford Wives question - Texas tranquilizer

In the movie, Paula Prentiss’ character “Bobby” refers to something called the Texas Tranquilizer where something in the water turned everyone in El Paso into placid, non-violent individuals. Do any of you guys know if this was a true event or was just fabricated for the movie?

El Paso has a high amount of lithium in the water.

Lithium is not a tranquilizer.

Pharmacology of Lithium Carbonate

Google is your friend.

http://www.lvwd.org/faq.htm