"On one occasion, Downing instructed Unger to beat an effigy of his mother with a tennis racket, as though killing her, and encouraged Unger to scream at his mother while beating her effigy," the suit said.
"Conversion therapy was, in Unger's experience, 'psychological abuse,'" it said. "By the time he terminated sessions with JONAH, he was deeply depressed and had commenced taking antidepressant medications."
Downing "picked apart every human emotion and childhood disappointment" of Unger, to present them as treatable origins of Unger's orientation, the suit said.
"I watched as grown men were frenzied into fits of emotional rage against their mothers and encouraged to act out physical violence against their parents in order to access their so-called true manhood and become more heterosexual," Ferguson told reporters Tuesday.
Unger's ability to have physical and emotional relationships with men was impaired and he was unable to work for a year, the suit said.
Bruck, Levin, Unger and Ferguson are "adjusting well" four years after their last conversion therapy treatments, according to Wolfe. "They have had time to get on with their lives," he said.
Their lawsuit should put all conversion therapists on notice that they can be held accountable, Wolfe said.
The SPLC has identified 70 conversion therapy providers across the United States. A California law signed by Gov. Jerry Brown last month made it illegal for licensed counselors to use the therapy with clients under 18.
"We really want to bring this lawsuit to bring attention to this practice that takes place in many parts of the country, preying on vulnerable young people," Wolfe said.