Your favourite reality TV contestants all have one very dangerous thing in common.

This week, Michelle from Seven Year Switch wrote exclusively for Mamamia about the Post-Natal Depression that plagued her both during the lead up to and at the time of her time in reality TV.

Michelle’s story is a moving account of a mother struggling to come to terms with a mental illness. It’s a vital message to spread to new mothers.

It’s also a cautionary tale about the dangers of reality TV.

We hear it all the time: what TV crews are looking for are characters. When casting for reality TV, their goal is to combine as many big, wild, unpredictable personalities as possible in the hope that the contestants in question might react spectacularly under the pressure of cameras.

The people producers want for shows like The Bachelor, Seven Year Switch, My Kitchen Rules and First Dates are outrageous and volatile. They say and do things the viewer sitting at home can’t imagine saying or doing, let alone on television.

We laugh and call these people “crazy” from our lounge rooms, but the jokes of the audience too often touch on a dark truth: the most popular contestants on reality TV are often those with underlying mental illnesses.

Michelle's story isn't the first time an Australian celebrity has spoken about her struggles in the reality TV limelight.

Tully Smyth, a contestant on 2013's Big Brother, penned a blog post after she was evicted from the house, calling for psychological monitoring of all reality TV contestants. She wrote:

All shows on all networks should have a compulsory check with an independent psychologist once a week... [including] 6-12 months after the completion of the program.

At first glance, her insistence on ongoing support for contestants, even after shows have finished, might seem like overkill, but the statistics tell another story.

Since 2006, there have been 21 deaths worldwide as a result of participating in reality television.

Rachel Brown, a 41-year-old contestant on Gordon Ramsay's Hell's Kitchen, shot herself in 2007 after being ridiculed by Ramsay. Three years later, another contestant on a Ramsay cooking show, Joseph Cerniglia, jumped off a bridge.

In 2010, British Big Brother star Nadia Almada attempted suicide after being voted off the show.

In 2008, ridiculed American Idol contestant Paula Goodspeed fatally overdosed outside judge Paula Abdul's home.

In 2011, a contestant on American show Paradise Hotel 2, Nathan Clutter, jumped to his death from a cell tower after being voted off the show.

Three separate contestants on the American The Bachelor have taken their own lives: Julien Hug in 2010, Gia Allemand in 2013 and Alexa McAllister early this year.

Some of these contestants had pre-existing mental illnesses. Others were pushed over the edge by being ridiculed or poorly portrayed on national television.

One thing is clear, though: the psychological ramifications of being on reality TV can be fatal.

It's a message that might be hard to hear for reality TV audiences and producers alike. These people, after all, are reality television's bread and butter.

The problem with reality TV, at its heart, is with the sorts of interactions people want to watch. The more the audience responds positively to hysterical, "crazy" characters by tuning in, the more TV executives seek them out. By encouraging contestants to play into negative stereotypes like "the crazy one" and "the villain", we've created a market where unstable personalities are desirable.

Worse, there's little motivation for producers to follow Tully Smythe's advice and provide psychological support for contestants when it's the lack of such support that makes such excellent television.

It's a problem that's not easily fixed, but giving contestants access to counsellors during and after their time on the show would be an excellent start.

It takes a certain kind of personality to go on reality television. Watch the first kiss between two strangers on new show Kiss Bang Love...