The Member for Leichhardt, a sprawling electorate in far north Queensland, is one of Parliament House's big characters, a former toilet cleaner, RAAF serviceman, union representative and wildlife catcher. But now he felt so small.

It was 1999 and the Kim Beazley-led Labor opposition was hounding him over a Defence Force contract awarded to a concrete company of which he was a director and company secretary. Reporters staked out his family farm, begging his neighbours and relatives for dirt on him. His face beamed from the TV set of every airport lounge he entered, yet another politician drenched in muck.

"It was 10 days of absolute hell," he says.  "I was sick. I was devastated. I had to go to Canberra Hospital for chest pains. There were a couple of days where I couldn't get off the couch in my office."

Fifteen years later, you can still hear a crack in his voice. The anguish is raw. The past is never really past.

"I always feel for someone who is getting beaten up by the media – what you go through from a mental health perspective is absolutely intense.

"For some people it is the final straw."

Entsch, 64, always insisted he had done nothing wrong, and Labor eventually abandoned a bid to take him to the High Court. He made a vow: to help any fellow politicians who find themselves in a similar position.

"Whenever I hear of anyone in crisis or with conflict in their lives I am the first person to go support them."

They speak about marriage breakdowns. Problems with their kids. Alcohol abuse. A scandal hovering above their heads like a giant wave about to break. Some MPs have admitted to thinking about suicide.

Religious or not, Entsch will often refer them to Peter Rose, the official Parliament House chaplain. Every federal politician interviewed for this piece mentioned Rose – known affectionately as "the padre" – and praised him highly.

"I have his number on speed dial and so do many MPs," Entsch said.

Another port of call, until his retirement last year, was WA Liberal MP Mal Washer. A registered GP, Washer was known as the "doctor in the house". Politicians from all sides of politics and their staffers went to him for advice and to have their scripts filled.

Washer estimates about 20 per cent of those working in Parliament House are on anti-depressants. Many more take sleeping medication.

"There was a significant amount of depression," he says. "People felt flat and dejected. Lonely, lost and isolated.

"It's a very isolating feeling to be a politician."

Indeed, it was Winston Churchill, wartime Prime Minister of the United Kingdom, who first used the term "black dog" to describe his own battle with depression.

One of the many MPs who visited Washer for a consultation was Andrew Robb, then a senior opposition frontbencher. In 2009 Robb revealed he had depression and took three months' leave.

Former NSW Liberal leader John Brogden, now chairman of mental health charity Lifeline, says Robb's decision to go public shows that attitudes to mental illness are improving. Brodgen was admitted to hospital in 2005 after revelations he had made unwelcome sexual advances to two female journalists.

"When I had my suicide attempt, the premier and my successor gave me leave for as long as I wanted," he says.

"Despite that, I didn't believe the media would let me recover in private if I stayed as a politician.

"Andrew's success as an opposition frontbencher and trade minister is demonstration that things have changed."

That's not to say they are perfect.

"The stigma has moved on a bit but it is still there," Robb told Radio National last week. "It is a very competitive field, politics. Once I re-engaged fully – and on occasions when I was challenging for different leadership positions – I know it was used against me with media and others to try and create a sense that I was not stable enough to hold down senior positions."

Warren Entsch says Parliament House is more hostile than ever.

"It's getting more and more adversarial. There are haters there which is very sad."

All agree that the Gillard minority government was an especially brutal period.

And, at the height of the question time nastiness, Speaker Anna Burke stopped proceedings to remind MPs of Greg Wilton a Labor MP who committed suicide in 2000. A framed photograph of Wilton, a fitness fanatic, still hangs by the entrance to the parliamentary gym.

"At that point we all became more conscious of the issue than we had been. Until then it wasn't on our radar," says Labor MP Joel Fitzgibbon, a friend of Wilton's.

"Most of us vowed to be more friendly and kinder to each other. Some stuck to that promise; many didn't.

"In the 43rd parliament I saw unjustifiable behaviour by people prepared to go after someone despite their vulnerabilities."

At the height of the scandal surrounding Craig Thomson, who was later found guilty of defrauding the Health Services Union, the Coalition indicated it would not give Thomson leave for the birth of his child.

"I said, 'This is bull---t. Don't do this'," says Mal Washer. "I said, 'Enough is enough, let's leave this guy alone.'"

In the end, Thomson was granted leave.

Personal crises can bring out the best – as well as the worst – in our politicians.

"In times like that you see extraordinary acts of generosity and kindness," Entsch says.

"People who were totally critical of Peter Slipper [the former Speaker accused of sexually harassing a staffer] still reached out to put politics aside and offer him a level of comfort."

Slipper's psychiatrist told a court this year he has been suffering from depression and has twice attempted suicide.)

As opposing party whips in the minority parliament, Entsch and Fitzgibbon worked closely together to arrange leave and support services for any politicians in distress.

"I would accept on face value when he told me someone had a crisis and he would accept mine – even if the leadership wasn't happy about it," Entsch says.

"I will rip someone in leadership a second one if I think they are acting against a member's interests."

Washer says it is often life after politics that proves the toughest.

"It's like a divorce. You feel no one loves you. It can be hard to get work. The bulk of people really floundered in the real world."

Politics is a unique profession with intense public scrutiny. But are the mental health problems politicians face really so different to those of ordinary Australians?

Think of the isolation of the fly-in fly-out worker or the office clerk too afraid to tell their boss about their depression or anxiety.

"Many people are still afraid about losing their job or being overlooked for promotion if they talk about it," says Brogden.

"Mental illness should be treated the same as a physical illness. That is a much better culture than having people sit at work suffering and not seeking leave or support because they are worried about their job."

Says Entsch: "People in politics are no different to anyone else. We take the same medications. We have the same challenges and frailties."

The more people who come forward to talk about mental health the easier it will become, he says.

"It makes people feel that they're not alone."

Lifeline 131 114

MensLine 1300 789 978

Beyondblue 1300 224 636