Dr. Robert Spitzer tells The New York Times that he “regrets” his own 2001 study which concluded that some gay people could alter their sexuality.

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.

Spitzer first made a retraction in a story published in the American Prospect.

The Times goes a bit further, to the moment when Spitzer first conceded publicly that he had made a mistake.

It was while talking to Gabriel Arana, the American Prospect journalist. Arana, who is gay, went through the therapy himself as a teenage and he described his experience in his story.

“I asked him about all his critics, and he just came out and said, 'I think they're largely correct,'” Arana told the paper. “But at the time I was recruited for the Spitzer study, I was referred as a success story. I would have said I was making progress.”

Spitzer, now nearly 80 and suffering from Parkinson's disease, said: “You know, it's the only regret I have; the only professional one. And I think, in the history of psychiatry, I don't know that I've ever seen a scientist write a letter saying that the data were all there but were totally misinterpreted. Who admitted that and who apologized to his readers. That's something, don't you think?”

Spitzer admits to this in a letter to be published this month in the same journal where his original study appeared.

“I believe, I owe the gay community an apology,” the letter concludes.

(Related: Rachel Maddow: Robert Spitzer's “ex-gay” recant could bolster gay marriage case.)