Washington state Governor Jay Inslee, a Democrat, on Thursday signed a bill that bans therapies that attempt to alter the sexual orientation or gender identity of lesbian, gay, bisexual and transgender youth.

Such therapies go by names such as “conversion therapy,” “reparative therapy” or “ex-gay therapy.”

At a signing ceremony in Olympia, Inslee described such therapies as “abuse.”

“Conversion therapy is not so much therapy, it's abuse, and we are today prohibiting the abuse of our children,” Inslee said. “Conversion therapy, which has caused scars for decades across the country of something that is inhumane and not acceptable in the state of Washington.”

Chad Griffin, president of the Human Rights Campaign (HRC), the nation's largest LGBT rights advocate, was among the LGBT activists joining Inslee as he signed the bill into law.

“For far too long, con artists peddling junk science have been allowed to get away with inflicting deep, lasting and irreparable harm to far too many LGBTQ people,” Griffin said. “Make no mistake about it: So-called conversion therapy is a child abuse.”

Connecticut, California, Nevada, New Jersey, Oregon, Illinois, Vermont, New York, Rhode Island, New Mexico and the District of Columbia have enacted similar bans. Similar bills have been introduced this legislative session in New Hampshire, Maryland and Virginia. An increasing number of local municipalities have also enacted similar protections, particularly in Florida. Earlier this week, Milwaukee became the first municipality in Wisconsin to enact such a ban.

(Related: “Ex-gay” therapy ban clears Maryland Senate.)