The number mental health advocates want you to talk about

Untreated mental illness costs the U.S. $105 billion in lost productivity each year, according to Mental Health America, an advocacy group.

What's more, the National Council for Community Behavioral Healthcare says people with untreated mental illness are four to six times more likely to be incarcerated and are more likely to hit emergency rooms for acute care.

So the folks at Mental Health America are encouraging people as part of Mental Health Month to complete a three-minute online screening.

"It's a mental health checkup you can take online, make sure that you're in good mental health," Steve Vetzner, media relations director at Mental Health America tells me. "If there are any problems you can take it to your physician."

From there, Vetzner says, a doctor will probably administer more tests.

The three-minute screening flags mood and anxiety disorders such as depression and post-traumatic stress disorder.

"Since May is Mental Health Month, it's the perfect time for people to get screened, get their score - and then share that information privately with their health care provider," according to the Mental Health America website.

Here's how it works. Users fill out a 27-item checklist.

http://www.whatsmym3.com/Screening/Screening.aspx

They can then email results of the screening to a physician, but it's only meant to be a first step toward a real diagnosis.

The site is also encouraging users to let their social networks know: " Everyone has a number. #WhatsYourNumber. It only takes three minutes to find out," they ask on a Tumblr page.