More recently, "one of my friends hung himself on New Year's Eve," he told CNN. "But for the grace of God go I."
These experiences got him thinking about how he could help. Four months ago Padalecki felt he had to tell the world of his diagnosis, so he launched the charity #AlwaysKeepFighting
. It sold T-shirts -- more than 24,000 in the most recent campaign so far (with hundreds of thousands of dollars raised) -- to support various mental health causes, but it has been most effective in creating awareness and reducing stigma.
"When celebrities speak publicly about their own experiences with depression or other psychiatric conditions, it's very helpful," said Dr. Jeffrey Borenstein, president and CEO of the Brain and Behavior Research Foundation.
"It opens up a conversation about these issues. If someone you admire is going through the same thing you might be going through, it makes a difference with people, it causes people to seek help."
Similarly, basketball great Magic Johnson in the 1990s raised awareness about AIDS, followed by actor Michael J. Fox (Parkinson's), singer Demi Lovato (bipolar disorder) and rocker Bret Michaels (type 1 diabetes). The tragic loss of Robin Williams, who struggled with clinical depression
, and most recently the legal troubles and subsequent rehab stay for "Buffy the Vampire Slayer" actor Nicholas Brendon
have brought mental illness to the forefront in the past year.
Borenstein said that the people he has spoken to who either had depression or bipolar disorder include Jane Pauley, Patty Duke and the late Mike Wallace.
So Padalecki is not alone in coming forward, but he has most effectively used social media to support his campaign
At the same time, he doesn't want to be seen as the leader of a movement. "I'm just a part of this, not the head of it. I'm happy to be one of the public faces of it, but I don't stand alone up here."
Fans showed their solidarity with the actor earlier this month at San Diego Comic-Con, and Padalecki hopes he can return the favor. "For those who don't have millions of Twitter followers who have your back, I've got your back."
"I still deal with anxiety on a daily basis," Padelecki said. "A lot of artists are emotional beings, but we have to behave like, 'Hey I'm great, I'm living the life!' That's what we think the audience wants."
But to the young actor, "life and art are about being there for someone and someone being there for you. For me, life is about deeper meaning. I've always tended towards honesty and being forthright. I've been lucky that anytime I've been honest, I've been approached with sincerity."