Gov. Jerry Brown signed a bill Saturday to outlaw those types of therapies, the San Francisco Chronicle reported.
The bill, sponsored by State Sen. Ted Lieu, D-Torrance, bars mental health practitioners from giving so-called reparative therapy, which professional psychological organizations and gay rights groups have said may cause harm.
"This bill bans non-scientific 'therapies' that have driven young people to depression and suicide. These practices have no basis in science or medicine and they will now be relegated to the dustbin of quackery," Brown said in a statement to the Chronicle.
Under the law, which takes effect Jan. 1, no mental health provider will be able to give therapy that seeks "to change behaviors or gender expressions, or to eliminate or reduce sexual or romantic attractions or feelings toward individuals of the same sex."
"LGBT youth will now be protected from a practice that has not only been debunked as junk science, but has been proven to have drastically negative effects on their well-being. We commend Gov. Brown for putting children first, and call on all states to take California's lead on this issue," said Chad Griffin, president of the Human Rights Campaign.