The National Association for Research & Therapy of Homosexuality (NARTH), formerly the National Association for Research and Treatment of Homosexuality, is a non-profit organization dedicated to "affirming a complementary, male-female model of gender and sexuality". NARTH is part of the ex-gay movement that advocates using reparative therapy to convert people who experience same-sex sexual attraction to a heterosexual orientation. NARTH advocates questioning the circumstances surrounding the American Psychiatric Association's 1973 declaration that homosexuality is not a mental disorder.