One of the world’s leading psychologists recently apologised to the gay community for attempting to proffer a cure for homosexuality.

79-year-old Dr. Robert Spitzer considered by some to be the father of modern psychiatry couldn’t go on with his career or even his life knowing he had poorly conceived a 2003 investigation that supported the use of reparative therapy to “cure” homosexuality for people strongly motivated to change. In a recent letter, the scientist wrote: “I believe I owe the gay community an apology.”

The New York Times reports that it had taken Spitzer 9 years to admit his theory on curing homosexuality is wrong. The highly-criticized study, which was published in the prestigious Archives of Sexual Behavior, alleged that “highly motivated” gay men and lesbians could alter their sexuality. “I apologize to any gay person who wasted time and energy undergoing some form of reparative therapy because they believed that I had proven that reparative therapy works with some ‘highly motivated’ individuals. It’s the only regret I have; the only professional one,” Dr. Spitzer told the New York Times.

His apology came just as the World Health Organization (WHO) released a report  denouncing so-called conversion therapies for gays and lesbians.

Pan-American Health Organization Director Dr. Mirta Roses Periago said in the WHO study:

“Since homosexuality is not a disorder or a disease, it does not require a cure. There is no medical indication for changing sexual orientation,” Periago said. “Practices known as ‘reparative therapy’ or ‘conversion therapy’ represent a serious threat to the health and well-being—even the lives—of affected people.”

In defence of Spitzer, the executive director of Truth Wins Out, a nonprofit group that fights anti-gay bias, Wayne Besen said Dr. Spitzer in no way implied in the study that being gay was a choice, or that it was possible for anyone who wanted to change to do so in therapy.

After conversations with several science writers and reporters and watching gay rights issues gain traction in the United States and around the world, Dr. Spitzer had a change of heart about his theory, according to gay-rights website Truth Wins Out.