There are Adelaide Crows trinkets. Star Trek memorabilia. A Mike "Mr Cricket" Hussey punching bag. And a Lego space shuttle she built herself. She has an efficient air and a down-to-earth manner, responsible for the bureaucracy that provides health care to the Australian Defence Force's 58,000 full-time members.

Defence health includes rehabilitation procedures, mental health support and fit-for-combat strategies. It's a system that costs taxpayers about $9.7 million a week, a major responsibility for the person in charge.

A member of the Prime Minister's Advisory Council for Veterans' Mental Health, Dr Smart says she has seen mental health care of the serving troops become more critical during her 34 years in the air force. She says there is a desire from the top brass to ensure personnel are more mentally resilient once they leave Defence.

Dr Smart was made an officer in the military division of the Order of the Australia (AO) in this year's Queen's Birthday honours, for her distinguished service in medical and health services, described as a senior medical officer "of rare skill and ability".

"I choose to look at it as a reward for all the work health has done [in Defence]," she said.

Dr Smart, 56, will be leaving her job at the end of the year after four years performing essentially two roles.

As commander joint health, she oversees 59 Defence health centres around the nation set up for the serving personnel, including centres at Duntroon, Harman and Russell.

As the surgeon general, her job is to provide strategic advice about that health system to the chief of the Defence Force as well as maintaining oversight of the whole health care machinations, including ensuring deployed troops are fit to fight. Dr Smart will remain in the reserves after she leaves.

"I think it's a good time to move. I'm handing it on to my deputy at the moment. There's a lot of exciting things happening and we're on the cusp of a lot of stuff so I think it's good to have some different ideas," she said.

"When I got into the job it was a three-year posting and they asked me to extend for a year and I was quite happy to do that."

Her purview is looking after the health and welfare of current Defence personnel, rather than veterans. But she says that line of demarcation has softened and there is a real desire to ensure members leave Defence with life-long resilience, under the mantra "fit to fight and fit for life".

"I think since I've been in the job, we've taken mental health to a new level. That's been really important to me and to everyone," Dr Smart said.

"We've got data now that says our suicide rate is less than half that of the general population while serving in Defence. Of course, that gets lost in the politics and the media when you talk about the veteran suicide rate.

"But while in Defence, we've done a lot of really good work on mental health awareness and suicide prevention."

She says the thrust of a Productivity Commission report, which earlier this year recommended "fundamental reform" to the Department of Veterans' Affairs, was in line with the thinking within her own bureaucracy.

The report called for a sharper focus on the prevention of illness and injury within the Defence and veteran communities as well as a "whole-of-life" focus, to help Defence personnel as they moved to life as civilians.

"I think that's just reflecting what we've been saying for a while in 'fit to fight, fit for life'," Dr Smart said.

"I think in the past, when I came in, the attitude was, 'We've got them for 20-odd years, that's all we need to worry about and then they go and it's someone else's problem'.

"What we've been working on is, 'How can we set people up better for success when they leave?' and working on the handover to DVA.

"Whereas in the past we'd say, 'Yep, go to DVA', we do all the handovers now, from rehab provider to rehab provider and, if possible, ensure the same rehab provider, just a different person pays. We actually write letters to GPs now saying, 'This person is leaving [Defence], these are their medical problems'. So, we're trying to be a bit more cognisant. And, also, the prevention, the resilience training that we do, is trying to give them the basics so they stay fit as long as they can."

And she says stigmas around mental health are being worn down, as much in Defence as the mainstream community.

"There's this whole narrative out there that people can't put their hand up for mental health because it will be career suicide. What they mean is they think, oh, we'll stop them deploying. What we're actually doing there is saying, 'Well, you're at increased risk at the moment'. So, it's not that we're going to ruin your career, It's just that we want to spend a bit of time with you, making you better, so you can deploy the next time," she said.

"We also deploy people, depending on where they deploy to, on anti-depressants. Because we know if they're OK on anti-depressants, you wouldn't take them off it. So, we've started chipping away at that view."

Dr Smart has been on her own journey as a woman, and a gay woman, reaching the top echelons of Defence.

"I know a lot of women in Defence have struggled, especially in non-traditional roles," she said.

"There's still a bit of unconscious bias around but, generally speaking, I've always found it hasn't been an issue for me being a woman. But I'm in the health world in Defence. It's the most female-dominated part of a male-dominated organisation, if you like."

Being gay has been even less of an issue, she says.

"I've felt nothing but support. Sometimes over the top support," she said, with a laugh.

"It's been interesting. I've led the Mardi Gras parade a couple of times for the ADF but I haven't done a lot of activism.

"I think just being visible and high-ranking has had an effect. When I look back and look at the journey the ADF has been on since I joined, it's been remarkable, actually.

"We'll always be a conservative organisation but the way we've moved from really bad things that have happened to diversity and now inclusiveness, I'm really proud of it."

She lives with partner Lisa Padzensky, a driver for OzHarvest, in Tuggeranong, with their cat Xena.

With a dry sense of humour and a no-nonsense attitude, Dr Smart was raised in Kangarilla, a speck of a town with fewer than 1000 residents, south of Adelaide. She was a smart kid from the country, the daughter of a farmer and teacher's aid, who never had a burning desire to join the Defence Force. She had considered the navy until she learnt women couldn't go to sea. (That didn't start to happen until the mid-1980s). A school career counsellor encouraged her to study medicine, which she did, at Flinders University, the leader-in-waiting still a long way from emerging.

"I was very much out of my comfort zone," she said, of starting university. "True story - the first few months of uni, I used to eat my lunch in the car because I was just too shy to go and sit in the cafeteria. So it took me a while to adjust to the big smoke of Adelaide."

Half-way through her medical degree she joined the air force, enticed by the promise of a bursary of about $12,000 that would help her give up a couple of her part-time jobs.

"I joined the air force mainly because there were a couple of people in my class talking about it, but I did have an uncle who served in World War II. He didn't come home, he was a Wellington pilot. And so, I think the air force did appeal because I always saw his picture up on the wall at my Grandma's house."

She started with the air force full-time in 1989 at Amberley in Queensland, seeing air force patients on the base as a medical officer. She also served at Pearce air force base in WA. She studied for her diploma of aviation medicine in London, which convinced her Defence would be her career.

Among her testing deployments was one to Rwanda in 1995.

Dr Smart was deployed to the United Nations Assistance Mission in Rwanda as senior RAAF officer and aeromedical evacuation co-ordinator. She was stationed at a hospital for the UN contingent but she and her unit ended up treating mostly local Rwandans.

"I wouldn't say I enjoyed the experience, but it was an amazing experience and I think it really taught me so much about who I am as a person and how I could deal with bad stuff," she said.

In April 1995, at least 4000 people in the Kibheo displaced persons camp in Rwanda were slaughtered by militants. Dr Smart remembers visiting the camp in the weeks after the carnage, trying to convince terrified survivors that they had to leave the squalid, filthy conditions to be treated in hospital.

"We'd go in with flak jackets and helmets and rifles, because there'd been snipers there. So we'd be going in and trying to convince people to leave the camp to give them health treatment, because we didn't want to treat them in those unhygenic conditions," she said.

"And we also needed to clear the camp. I remember one case where we had to say to a mother, 'Your baby's not well and you have to come' or "Can we take the baby?' 'No, no, no.' 'Come with us?' 'No, no, no.' And the baby died."

She marvels, now, at how little mental health support there was for troops just 20 or so years ago.

"Back then, we didn't really have any, that I can remember, specific psychological preparation. In fact, less than 50 per cent of medical company had ever been overseas before and they lob into the middle of Africa, in the mid-90s without internet, with no connection to home," she said.

"We didn't really prepare people, because we didn't know how to. And we didn't have the great system we've got now where, before you come home, you get a psyc screen to look at if you are at increased risk of problems. And then six months later you have another screen. We didn't have any of that."

Dr Smart said it did take her time to get over the Rwanda experience.

"My very amusing housemate at the time called me The Yobette. He saw me come home and he reckoned he'd say, 'Do you want to go out somewhere on the weekend?'. And I'd go, 'No, I'm fine, I'm watching the cricket'. And then he'd come home and I'd be in exactly the same position on the couch," she said.

"He was good though. He did drag me out to places.

"The first time I went to a shopping centre I felt very anxious because I hadn't been outside the wire mostly, apart from a couple of leave passes, without my rifle and I was used to seeing the same few hundred people's faces and I couldn't deal in that situation.

"That was just a transient thing for me, I worked through it. So I think that whole, 'what doesn't kill you makes you strong', the post-traumatic growth they're talking about now, I think I learned, even if things are bad, I, at least, had ways of coping and getting through it without too much psychological scarring."

Dr Smart, however, says her post traumatic experience in Defence was not Rwanda, but a tragic incident for which she would eventually receive a Chief of Air Force commendation.

It was the aftermath of an F-111 crash off Malaysia in 1999 that killed the pilot, Fight Lieutenant Anthony Short, 31, and his navigator, Squadron Leader Stephen Hobbs, 33.

Dr Smart was on the team that retrieved the bodies and helped investigate the accident.

"I knew the pilot, I knew his wife, she was a reserve doctor. The nav I didn't know as well but his wife and I were in the same building when I first came into the air force," she said.

"We were in a swamp in the middle of this island in the tropics. It was hot and we were based on a ship. We had to helicopter into this swamp and try to get through all this mud to basically grab the bodies and bring them back.

"But at the same time, we had to gather evidence for the accident investigation. The second main day, I was physically ill in the morning, I didn't want to do it. And I was also dreaming a little bit of being in Rwanda again.

"But again, I pulled through. I learnt from Rwanda. When I got back, I organised follow-up psychologists for all of the team. And I also went to see a psychologists to be debriefed. Again, I'd learnt the lesson."

Dr Smart may have started in Defence slightly equivocal, but after more than three decades, she is passionate about her job.

"There's certainly a sense of serving my country, which is very strong," she said.

"I always say putting on my uniform every day, putting this on [the commendation], the Rwanda medal, that sense of serving my country becomes very clear."

And she understands herself better.

"Doctors have to learn to compartmentalise to a degree. They have to be compassionate but objective. And they have to rationalise things in an objective way," she said,

"I think there's part of that I do reasonably well so I can keep functioning and deal with the other stuff later. But what I've learnt is that I also have to deal with that other stuff. When I get stressed, it manifests itself physically, so if I keep going to the gym and keep fit, that helps me."

She has a rallying cry that gets her through the toughest times.

"In Rwanda my mantra was, 'We're here to help and we're doing a good job'. And that's something, overall. I continue to believe."