California has become the first state in the nation to ban controversial gay "conversion" therapies for children under the age of 18.

Gov. Jerry Brown made the announcement on Sunday, revealing the law would go into effect on Jan. 1.

Licensed therapists will not be allowed to try any kind of "sexual orientation change efforts." The bill protects lesbian, gay, bisexual and transgender minors from "reparative" therapies administered by mental health professionals aimed at altering sexual orientation or gender identities and expressions.

''This bill bans non-scientific 'therapies' that have driven young people to depression and suicide," said Brown in a statement after he signed the bill into law. ''These practices have no basis in science or medicine, and they will now be relegated to the dustbin of quackery.''

The law was sponsored by the state senator Ted Lieu, and supported by a long list of medical and psychological societies, as well as by advocates for gay rights.

Also speaking up for the ban were former patients who described the emotional scars they said they were left with after being pushed into ex-gay therapy by their parents and finding they could not change their sexual orientation, or did not want to.

"Conversion" or "reparative" therapies include a wide variety of techniques, from counseling to shock therapy to, in extreme cases, exorcism, used in an attempt to "cure" individuals of their homosexual and transgender feelings.

However, in recent years, even those who once championed the idea that someone can convert to heterosexuality have admitted that viewpoint is flawed.

The Human Rights Campaign, an advocacy group for equal marriage and LGBT rights, said in a press release, "We're grateful to Governor Brown for standing with California's children. 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 Governor Brown for putting children first, and call on all states to take California's lead on this issue. We will continue our fight against this kind of child abuse, which has been deemed harmful to children by all major mental health, medical, and child welfare organizations."

While most reputable organizations have distanced themselves from conversion therapy, some religious conservatives still champion its use as a way to rid homosexuals as what they see as unwanted and immoral desires.