Politics is a pressured business. Any sign of personal weakness will be seized on by journalists and political opponents alike, and exploited to the full.
How extraordinary, then, that MPs would stand up of their own free will and admit to the kind of illnesses that have for many years been wrongly viewed as serious weaknesses.
"Some people in my family do not know about what I am going to talk about today," the Labour MP Kevan Jones said in an unexpectedly emotionally-charged speech in the Commons last week.
"Like a lot of men, I tried to deal with it myself - you do not talk to people. I hope you realise, Mr Speaker, that what I am saying is very difficult for me."
He admitted to suffering a deep depression in 1996. Another MP, Sarah Wollaston, said she had suffered from post-natal depression. Charles Walker, the Tory MP for Broxbourne, talked about his problems with obsessive compulsive disorder. "I am delighted to say that I have been a practising fruitcake for 31 years," he declared.
"I operate to the rule of four, so I have to do everything in evens. I have to wash my hands four times and I have to go in and out of a room four times. My wife and children often say I resemble an extra from 'Riverdance' as I bounce in and out of a room, switching lights off four times."
The mental image this produces is undoubtedly comic. But that's just Walker's way of dealing with a disorder which has, in the past, caused him immense mental distress. "It's part of me, it doesn't define me," he says. "Sometimes you just have to laugh about it - otherwise on occasions you'd be crying."
He's never got his OCD officially diagnosed, but that is something now being considered. Walker says he hasn't stopped smiling since the debate. Hundreds of emails have flooded into his inbox congratulating him for his candour.
"It's at its worst when one is most anxious," he says.
"We've got to be much more welcoming and relaxed, because if you're unwell it's so much easier to get better if you're not frightened and worrying about things. We need to create a stable, warm, loving environment for people with mental health problems so they can focus on themselves, and not worry about what we all think."
Campaigners keen to reduce the stigma attached to mental health have been celebrating the debate. Sue Baker, the director of the Time to Change programme run by Mind and Rethink Mental Illness, says she wants to build momentum towards undermining this taboo topic. "It's a marathon, not a sprint - we're overtaking generations of prejudice and misunderstanding," she says. Having tackled race, gender, sexuality, disability, faith issues and other areas, society now needs to deal with this last bastion of discrimination.
Baker points out that there are well over another 100 MPs who haven't yet disclosed their mental health difficulties. The more who do so the better, for they're setting an example to end this discrimination for good.
This isn't just about slowly changing society's attitudes. Another Tory MP, Gavin Barwell, is pushing to change the law through his private member's bill.
These very rarely actually become an act of parliament, but are a good way of pressuring the government to make changes themselves. Barwell's bill proposes ending the forced resignation of MPs from parliament if they are sectioned for more than six months. Anyone receiving any medical treatment for mental health problems means you're barred from jury service, and company directors also face a catch-all that blocks them from continuing if they've got mental health issues.
MPs talking openly about their mental health problems have other advantages, too. "I thought the debate last Thursday showed the Commons at its best," Barwell says. "It's hugely to their credit as individuals that they saiad what they had to say. It also makes the case for the bill - that parliament is immeasurably strengthened by having people who have experience of the things we're talking about."
This has been a big breakthrough for parliament, and for the politicians involved, but the mental health battle is going to continue throughout the summer and beyond. Barwell's legislation will next be before the Commons in September - and like many backbench MPs before him he is likely to find persuading the government to act is a much harder proposition than getting it to simply agree.
Mental health care provision is also not guaranteed. Despite all the attention being heaped on the issue at the moment it is competing with many other pressing priorities. With the NHS under intense pressure mental health is an easy target for spending cuts. So efforts to raise its profile will help ensure that existing levels of care continue to be offered, too.
For now, though, a message is being sent that being open about mental health issues is not a failing - far from it. Walker wants his openness to have made a difference: "I'm hoping that people who saw that debate have thought to themselves 'my word, if politicians can talk about it - admitting any kind of weakness was, we thought, political death - then perhaps we can talk about it openly and feel safe."