Joseph Nicolosi

Joseph Nicolosi (born January 21, 1947) is an American clinical psychologist, founder and director of the Thomas Aquinas Psychological Clinic, in Encino, California, and a former president of the National Association for Research and Therapy of Homosexuality (NARTH). Nicolosi has advocated and practiced reparative therapy, a highly controversial practice which purportedly helps people overcome or mitigate their homosexual desires and replace them with heterosexual ones, based on the premise that homosexuality, as opposed to heterosexuality, is pathological and/or sinful based on interpretations of some Biblical passages.
Nicolosi has described his theories in Reparative Therapy of Male Homosexuality: A New Clinical Approach and three other books. Nicolosi proposed that homosexuality is often the product of a condition he describes as gender-identity deficit caused by an alienation from, and perceived rejection by, individuals of the subject's gender. He holds a Ph.D. from the California School of Professional Psychology.