SAN FRANCISCO – Gay rights advocates are making plans to get other states to join California in banning psychotherapy aimed at making gay teenagers straight, even as opponents prepared Monday to sue to overturn the first law in the nation to take aim at the practice.

After months of intense lobbying, California Gov. Jerry Brown signed a bill late Saturday that prohibits licensed mental health professionals from using so-called reparative or conversion therapies with clients under age 18. Brown called the therapies "quackery" that "have no basis in science or medicine."

Two New Jersey lawmakers already are drafting similar legislation, while groups that helped get the California law passed are sharing research, witnesses and talking points with counterparts in other gay-friendly states, said Geoff Kors, senior legislative and policy strategist for the San Francisco-based National Center for Lesbian Rights.