* Social stigma a major barrier to seeking help - Obama
* Conference comes six months after school shooting
President Barack Obama said on Monday that Americans need to become more open about mental health issues so that people struggling with problems are not ashamed to seek help.
More than 60 percent of Americans with mental illness do not receive treatment, many of them because they are embarrassed or afraid of being ostracized, Obama said, speaking at a White House conference on mental health.
"We wouldn't accept it if only 40 percent of Americans with cancers got treatment," Obama said. "So why should we accept it when it comes to mental health?"
Obama promised to start a "national conversation" on mental health after the shooting deaths of 20 children and six adults at a Connecticut school last year, although he did not mention the tragedy in his remarks on Monday.
The massacre at the elementary school in Newtown, Connecticut, on Dec. 14 raised awareness of mental health issues, although little is known about the state of mind of the shooter, 20-year-old Adam Lanza, who committed suicide.
Lanza, who has been described as socially awkward and reclusive, also killed his mother.
"Without us knowing if and what Adam Lanza had, we certainly know that something bad was going on, and that Adam Lanza wasn't getting the attention that he needed," said Harold Koplewicz, president of the Child Mind Institute, a psychiatric treatment and research center in New York City, in an interview.
The conference at the White House is one of the less controversial tasks for Obama on his politically tough to-do list to address gun violence in America.
His proposals for new restrictions on guns have stalled in Congress, foiled by a tough fight from the powerful National Rifle Association and other groups defending Americans' constitutional rights to own guns.
But there are signs of bipartisan interest in Congress in taking steps to deal with the lack of access for mental health services and trained professionals in the field, said Koplewicz, whose opinions have been sought out by Republicans on Capitol Hill.
"Sometimes it takes these terrible national tragedies that capture us, that hit us in the pit of our stomach, and we say to ourselves: 'It's a wake-up call. Enough. We just have to do something,'" said Koplewicz.
ONE IN FIVE KIDS
Mental illness is common in America. As many as one in five children suffer from a disorder, the U.S. Center for Disease Control and Prevention has said.
People with mental illnesses statistically are far more likely to be the victims of violence than the perpetrators, and the vast majority of gun violence in America is not linked to people with mental problems.
"I want to be absolutely clear the overwhelming majority of people who suffer from mental illnesses are not violent," Obama said.
Yet many Americans fear people with mental illness, part of the hurdle for treatment, said actor Glenn Close, who spoke at the White House about the battles waged by her sister and nephew to recover from mental illnesses.
"The truth is, that stigma has hardly budged," said Close, who has worked to reduce stereotypes.
Treatment for mental illness is most effective when started early, but Obama said only about half of children with mental health problems receive treatment.
The health care reform law will expand insurance coverage for treatment of mental illnesses for about 60 million Americans when it is fully implemented, he said.
"We need to see it that men and women who would never hesitate to go see a doctor if they had a broken arm or came down with the flu, that they have that same attitude when it comes to their mental health," Obama said.
The problem is particularly acute for veterans struggling with brain injuries and post-traumatic stress. Obama said 22 veterans a day commit suicide.
"We've got to do a better job than that, of preventing these ... all-too-often silent tragedies," he said, noting the administration will hold mental health summits at veterans' health care centers across the country in coming weeks.