She is also a person who has lived with depression for almost half a century. Her remarkable odyssey has exposed her, very directly, to the constantly evolving spectrum of theories about and treatments for the condition over that time.

This has included time in mental hospitals such as the controversial Chelmsford Private Hospital, where she underwent deep sleep and electroconvulsive therapy (ECT), a range of medications including lithium, counselling or ''the talking cure'' and, most recently and successfully, cognitive behaviour therapy.

She has just published Inner Weather: Learning from depression, a book that is part autobiography and part compassionate advice that reflects on living out an extreme form of the human condition.

Dr Stewart said her experiences at Chelmsford in the early 1970s were not without some benefit.

''It [ECT] did work,'' she said. ''It gave me a little time but it did not solve the problem.

''Harry Bailey was convinced if there was something wrong with your mind there was something wrong with your brain - a very mechanistic, reductionist approach. He was a brilliant man in many ways but he wasn't sufficiently accountable because it was a small private hospital. For other people it [Chelmsford] caused tremendous trauma but I think he [Bailey] was well-intentioned.''

While writing the book had been a ''compelling task'', it took years to complete. ''[Publishing it] is like coming out; I didn't have to do it, in some ways I was reluctant to do it, but the book wouldn't let me go.''

Some of Dr Stewart's observations, such as saying she dealt with thoughts of suicide by simply saying ''no'' and that people with mental illness must help themselves, could prove controversial.

''It is important to get professional help when you need it,'' she said. ''But I really do believe that every person who suffers from a mental illness needs to find their own way of effectively managing their mind - and that is not easy to do.''

This is especially relevant to suicide. ''A large part of dealing with depression is dealing with dark thoughts. Sometimes you have to be very peremptory with them. [As for] that darkest thought of all, I don't think you should even conjure with it. I have seen what suicide does to the people who are left behind and the person who does it doesn't live to benefit from it.''

While there are no magic bullets for depression, Dr Stewart said she had spent a lifetime learning to live with it and now wanted to share that experience with others, including ''normal'' people. ''Everyone has tendencies this way,'' she said.

Cognitive behavioural therapy, which involves monitoring your ''inner weather'' and then taking active steps to change it, had come as a revelation.

''If only I had been introduced to it earlier,'' she said. ''Our thoughts, to a large extent, think us, rather than we them. To this day I must remind myself, again and again, that my thoughts are the depression.''

Inner Weather is published by Hybrid Publishers. RRP $24.95

For help or information call Lifeline on 131 114, or visit beyondblue.org, reachout.com and headspace.org.au