A further 6,000 tuned in over the web and at one point on Friday, the conference hashtag #Hope4MH trended on Twitter.
The conference was held at the Warrens' church, Saddleback, in California, and comes just under a year after the death of their son Matthew, who took his own life on 5 April 2013 after a lifelong struggle with mental health.
"To be able to call together the larger faith community is bittersweet, as we had hoped to share this moment with our son, talking about concern for people with mental illness," Kay Warren told reporters.
"We do this in honour and memory of our son and others lost to mental illness, realising there is hope for others dealing with this condition."
The Warrens held the conference jointly with the Roman Catholic Bishop of the Diocese of Orange, Kevin Vann, and the National Alliance on Mental Illness-Orange County (NAMI-OC).
Steve Pitman, President of NAMI-OC, noted how widespread an issue it is.
"There isn't a church or parish anywhere in the US or the world that is not affected by mental illness. The only difference is that some churches want to lead, discuss it and shed light on it, and others don't," he said.
Conference delegates heard of the need to work together in addressing mental health issues and removing stigma, while the church leaders among them were advised in providing effective and compassionate care to those struggling with mental health.
However, it was also a conference for those struggling personally with mental health issues, to be encouraged.
"I'm not an authority on mental illness, but I am an authority on living with mental illness," said Rick Warren. "We wanted to pull back the curtain and say, 'It's okay. I'm not okay, you're not okay, but that's okay because God's okay.'"
L to R: Teresa "Tita" Smith, Chuck Hannaford, Louise S Dunn, Tom Okamoto, and Rick Warren discuss aspects of mental health. (Saddleback Pics)
The conference heard how many people with a mental health issue turn to their faith leader for help in the first instance.
Bishop Vann said it was important that those seeking help in this area be treated sensitively.
"Western culture - or American culture - tends to rely on labels. They're limiting in a lot of ways, no matter what the label might be.
"We always have to let the Lord help us look and see the person behind the label who comes to us for help and healing."