"It meant he was opening himself up, he was being vulnerable, and he was realizing that his condition is nothing to be ashamed about," Karen Mangum said. "And he recognized that he has an influence that can be used for good. I think he has helped more people than he knew he could."
During BYU's football media day last week, the junior quarterback spoke at length about how the condition has impacted his life and football career, why he chose to divulge it publicly, how his coaches and teammates have reacted and how he hopes to help other people with similar struggles.
"When I made that post, I wasn't necessarily sure how it was going to go down, or what was going to happen," Mangum said. "But it has been great. I have been able to speak out at different events, different radio shows, and do interviews and talk with different people about it.
"It has really motivated me and inspired me to do more with it, to be able to continue to use my platform for good, to use the position that I am in to stand up for a good cause, and to reach more people, let them know they are not alone and really try to make a difference in that field."
Mangum said he has already taped a segment with CBS Sports Network that will run during the season.
One of those people Mangum has already reached is twice his age, BYU tight ends coach Steve Clark.
"I had no idea [about Mangum's depression], but I think it is more prevalent in society, and sports, than people realize," Clark said. "I was diagnosed 20 years ago with extreme clinical depression, so it really helped me when he started talking about it. I mean, I never talked about it. But I know how it is."
Clark, who is a distant cousin to Mangum, said 20 to 30 players in his 15-year college coaching career have told him about their mental health struggles.
Former Heisman Trophy winner Ty Detmer spends a lot of time with Mangum as BYU's offensive coordinator and says he also knew about the athlete's struggles, even while Mangum was putting on a happy face last fall when fifth-year senior Taysom Hill beat him for the starting quarterback job.
"It doesn't surprise me that he came out [publicly] with it," Detmer said. "He felt like he was in a good enough place, and was past all that so he could share it with others. The type of young man he is, the leader he is, he just felt like he could put himself out there."
As Mangum said in the April post, the diagnosis he was divulging "might be surprising to many, due to my normally optimistic, outgoing and happy personality." Indeed, reporters who have covered Mangum's career have said he was the last BYU player they would have guessed would have a mental health illness.
"But at the same time," Mangum said during media day, "I have always had that introspective, more emotional side to me that not a lot of people see, because usually it is when I am more alone, or in small groups. … So I think it is just a matter of understanding when those hard times come and dealing with them appropriately."
He said they don't come when he's at practice or playing football calling the game an "escape from everything where I can just go play and have fun and relax and let loose."
Rather, depression and anxiety set in "usually when I am alone or in certain situations where I feel more isolated and those emotions kinda get going and my mind starts racing, like at night before I go to bed," he said.
"It is hard to fall asleep sometimes. So it is just kind of understanding where and when it comes, and then being able to accept it, and just to embrace it and understand it and understand that it is OK. It is not the end of the world, and I don't have to be happy 100 percent of the time. I don't have to be smiling every day, all day. There are going to be times when I am frustrated or sad or down. But we are all human. We all go through times like that, and it is nothing to be ashamed of."
Like Clark, Detmer said depression is as common in athletics as it is in society as a whole. He saw it a lot in his 14 years in the NFL, especially among teammates who would retire and lose their lifelong identity as an athlete.
"Sometimes, you need a little help to get you over a hump, and Tanner has been through that," Detmer said. "Obviously, he has a great grasp of himself as a person and where he's at, and knows how to handle those things."
Karen Mangum said that's because her son got the help he needed, and has been surrounded by people who care and understand.
"Even in my circle of friendships and influence, people have come to me and said, 'please tell Tanner how thankful we are that he opened up, because what he said was nothing to be ashamed of,' " Karen Mangum said. "it is part of what his challenge is in life, just as if he had diabetes or cancer. We aren't afraid of sharing that information. Why are we afraid of talking about mental health? We shouldn't be.'
In the past three months, Tanner Mangum has proven that an accomplishment as impressive as anything he's done on the football field.
Tanner Mangum's key moments at BYU
Sept. 5, 2015 • Three months after returning from his mission, replaces injured QB Taysom Hill and throws a Hail Mary TD pass to give BYU a 33-28 win over Nebraska, as team finishes 9-4.
Aug. 23, 2016 • New BYU coach Kalani Sitake names fifth-year senior Hill the starting QB.
Dec. 21, 2016 • Replaces the injured Hill before the Poinsettia Bowl and guides the Cougars to a 24-21 win over Wyoming.
April 3, 2017 • Announces on social media that he suffers from "mild depression and anxiety," calls it a "mental illness."