Francois Morin — who has blogged extensively about his upbringing in the Church of Jesus Christ of Latter-day Saints, as the Mormons are known — had been seeking $4.5 million in damages.
He blamed his mental troubles on Mormon rituals he was subjected to at the age of 12.
He sued in 2012, but his case was dismissed by a lower court and the Quebec Court of Appeal.
He sought leave to appeal to the Supreme Court, but was turned down.
As usual, the court gave no reasons for refusing to hear the case.