TRENTON, N.J. (RNS) Licensed therapists are banned from using conversion therapy to try to change a child’s sexual orientation from gay to straight under a bill Gov. Chris Christie signed Monday (Aug. 19), making New Jersey the second state to prohibit the practice.

But a national Christian legal group that blocked an identical law from taking effect in California earlier this year vowed to sue New Jersey, saying the legislation violates the First Amendment rights of parents and therapists.

The new law prevents any licensed therapist, psychologist, social worker or counselors related to these professions from using sexual orientation change efforts with a children under age 18.

Offenders jeopardize their licensed status under the new law, which does not apply to clergy, or anyone who is not licensed by the state.

In his signing statement, Christie noted many leading health organizations had determined such therapy was ineffective and harmful.

"The American Psychological Association has found that efforts to change sexual orientation can pose critical health risks including, but not limited to, depression, substance abuse, social withdrawal, decreased self-esteem and suicidal thoughts," Christie wrote. "I believe that exposing children to these health risks without clear evidence of benefits that outweigh these serious risks is not appropriate."

Christie, a Catholic, had publicly stated his opposition to conversion therapy because he said he believes people are born gay. Asked about the bill at a campaign event on Monday, the Republican governor would only say, "The signing statement speaks for itself."

Liberty Counsel founder and chairman Mat Staver said his organization "will immediately file suit" at the request of New Jersey counselors and parents and national counseling organizations.

"The New Jersey governor is putting himself in every counseling room, dictating what kind of counseling clients can receive," Staver said. "This bill provides a slippery slope of government infringing upon the First Amendment rights of counselors to provide, and patients to receive, counseling consistent with their religious beliefs."

Troy Stevenson, who heads the state’s leading gay rights group, Garden State Equality, praised Christie. The bill will "protect young people from being abused by those they should trust the most, their parents and their ‘doctors,’" Stevenson said.

Stevenson said he hopes this "will lead to a further evolution" for Christie on same-sex marriage, which the governor opposes.

"It is our truest hope that the governor will realize ... the best way to ensure our LGBT youth are protected from the abuse of being ostracized, is to provide them with equality," he said.

The hearings on the bill draw angry responses from gay rights advocates, family groups and people who had freely used gay conversion therapy to lead heterosexual lives.

Arthur Goldberg, co-director of the Jersey City-based Jews Offering New Alternatives for Healing, called the law "a tragic mistake."

"There are teenagers who go to mom and dad and say ‘I don’t want to be this way,’ as long as voluntary and not coercive, what’s the problem?" he said.

Democratic State Sen. Raymond Lesniak, one of the bill’s sponsors, praised the governor’s actions.

"We aren’t telling parents how to raise their children with this law, we are acting to protect young people from abuse," Lesniak said. "If adults want to make the decision to undergo this process, they can. But minors don’t have the same free choice."

Mary Inzana, founder and CEO for Triad House in Ewing, one of three LGBT teen group homes nationally, said conversion therapy can have "destructive, devastating" effects on young people.

"One of the young teens we had in our care was previously told by his caregiver, that God did not want him to be gay. In fact he should 'forget' those feelings because he was being called to be a preacher of God’s word," Inzana said.

"The daily pressure to change who he was in the core of his being, and live a lie became too much to bear. This struggle escalated into a psychiatric crisis which ended in a suicide attempt, and hospitalization."

(Susan K. Livio writes for The Star-Ledger. Jenna Portnoy contributed to this story.)