08/10/2015 3:01 PM AEDT | Updated 15/07/2016 12:50 PM AEST

'Madness Made Me': The Breakdown That Shaped An Extraordinary Woman's Life

Madness Made Me from Loading Docs on Vimeo.

Mary O’Hagan believed she was destined for a life of institutionalisation after a major mental breakdown in young adulthood in the late 1970s.

The New Zealand woman was admitted to a mental health institution at the age of 18 with psychotic depression. Her traumatic episode lasted for eight years, until the age of 26, and she was told that she would never recover.

But she did, and now the woman who has advised the United Nations on mental illness wants to show others, in a documentary called 'Madness Made Me', that depression is not a life sentence.

"It was an incredibly challenging experience and when I look back on it I don't think anything that I've lived through since compares to it," O’Hagan told HuffPost Australia.

In the documentary O'Hagan confronts stigma, both from outside forces and within the mental health system itself, that branded her a lost cause.

Mary O'Hagan has advised the UN on mental health matters.

O’ Hagan was battling through an "existential crisis", and dealt with some of the questions that many people ask in their formative years: What are you here for? What is life about?

As the documentary reveals, the words used by the professionals looking after O’Hagan are stigmatised. Comparing them to her own account you can understand she was a woman fighting to get well while being pulled in the other direction.

But she recovered, she said, “by not believing them”.

"And this still goes on today, I was talking to someone currently in the system and the professionals say 'well you'll never get out of this, you'll have this probably forever', and it's just not true for a lot of people," she told HuffPost Australia.

"A lot of people come out of these experiences and go onto to live full and contributing lives."

Mary confronts the words written by her back in 1979 by the professionals. She replaces those words with excerpts from her diary -- her own account of that time.

So full and contributing has O’Hagan’s life been that she’s gone on to create her own social enterprise that helps bring peer-to-peer support for those battling mental illness.

She advised on the drafting of the UN Convention on the Rights of Persons with Disabilities.

"My last hopistalisation was when I was 26. I kind of stabilised a lot after that. It took a few years. It's like a bouncing ball. It bounces a little less every time," she said.

"I was then a commissioner at NZ Health Commission for six years. And now I run a social enterprise where we have developed Peer Zone, peer workshops in mental health, and developing an online recovery tool.”

As O’Hagan’s life has been so deeply entrenched in either experiencing, recovering from or supporting education on mental illness, that she has formed strong opinions on how both society and the system react to crisis.

"I think what our society tends to do, is to invalidate the experiences people have and I think that's kind of dangerous because it opens the door to a lot of stigma and discrimination. And also opens the door to a lot of coercion within the mental health system," she told HuffPost Australia.

"And I don't think it's helpful to people to say ‘You've got these experiences because you've got a pathology in your brain’, and this is the professional version, and ‘You can't help it at all and we'll come and take over your life for you’.

"And then you've got the community version, which is much less sophisticated, which is ‘Oh, you're weird, you're strange we don't relate to your experience at all, therefore we're going to shun you and we’ll think of you as someone who is other than us'. And that's not very helpful either.”

Mary believes at the very core of the problem, society and the system have a poor attitude towards mental illness.

The stigma, of course, is down a lack of understanding and perspective, O’Hagan said.

"At the core of any change we need to challenge peoples attitudes towards these experiences.

"I think people with lived experience need to enter into academia and public discourse and write novels and talk about their experiences publicly.

"The problem isn't just in the community but right in the service system. And I think in some ways the professional attitudes are just as harmful.

"I think there's a whole bunch of things we need to do to nudge people to have more helpful attitudes."

This documentary, created by Loading Docs, was based on Mary O'Hagan's memoir. You can access of copy of Madness Made Me by heading over here.

If you need help in a crisis, call Lifeline on 13 11 14. For further information about depression contact beyondBlue on 1300224636 or talk to your GP, local health professional or someone you trust.