"She got out of the car on Interstate 65 in Nashville and walked into oncoming traffic," he said.
"I grabbed her and pulled her back on the gravel shoulder of the road."
The "Jumanji: Welcome To The Jungle" star added: "What's crazy about that suicide attempt is that to this day, she has no recollection of it whatsoever. Probably best she doesn't."
Years later, Johnson's dream of being a professional football player was shattered after numerous injuries. He signed with the Canadian Football League but was let go within a year.
Shortly afterwards, Johnson's girlfriend broke up with him. "That was my absolute worst time," he said.
But he went on to rule the wrestling ring before turning to acting in 2000.
Johnson says had he not found the inner strength to carry on, he could easily have become suicidal like his mother.
"We both healed but we have always got to do our best to pay attention when other people are in pain," he said.
"We have to help them through it and remind them they are not alone."
When a fan told him he was suffering depression, Johnson wrote back: "I hear you. I've battled that beast more than once."
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)