Question: What is Santa Rosa Mental Institution?
Santa Rosa Mental Institution was first introduced in Episode 2x18, Dave.
Answer: Santa Rosa Mental Institution is the mental hospital where Hurley stayed for a while. It's a private mental health care facility outside of Los Angeles. Hurley was put into the institution because he shut down after four people were killed after a deck collapsed when he walked out onto it.
At the institution, Hurley met his doctor, Dr. Brooks. He also had an imaginary friend named Dave, who encouraged Hurley to eat when he shouldn't. Hurley was cured after getting rid of Dave.
Other residents of the hospital included Locke's biological mother and Libby.
In the future, Hurley wants to and does go back to Santa Rosa. While there, Charlie often hangs out with him and gives him messages such as, "They need you."
