The six-year-old girl who had a heart attack on the trampoline was a low point, but equally so are the days she might sit for hours with an elderly patient with a broken limb.

The extended care paramedic had not given much thought to how working for NSW Ambulance might affect her mental health before she joined the service but now she certainly knows.

"Sometimes your bucket can start to get quite full and it's that last patient who was really lovely and reminds you of your grandmother that really hits home," she said.

It is those days that she speaks to her colleagues, her family and the peer support officer, because that's what she has learned to do and it helps.

Emergency services instinctively react to crisis situations, but mounting compensation claims, adverse publicity and a growing number of employees retired hurt on duty with mental illnesses have forced them to reconsider this strategy when it comes to their own staff.

A mental health strategy released by the NSW Government on Wednesday turns the "crisis response" mentality upside-down and places prevention at the forefront of mental health care, with staff encouraged to be aware of potential issues from the beginning of their career.

The Mental Health and Wellbeing Strategy sets out objectives including: the promotion of staff wellbeing throughout their careers; developing resilience; creating a culture that identifies mental health problems early and encourages people to seek help; acknowledges the consequences of repeated mental health trauma; and continues to develop evidence-based interventions.

The strategy is a collaboration between the NSW Mental Health Commission, University of NSW and the Black Dog Institute, Fire and Rescue NSW, the NSW Ambulance, NSW Police Force, NSW State Emergency Service and the NSW Rural Fire Service.

Mental Health Minister Pru Goward​ said the strategy marked a shift in the way that first responder organisations approached mental distress among their employees and was the first such collaboration in Australia.

"I think it's been variable how they've supported them in the past but there's absolutely no doubt that the chief executives of all these organisations have recognised that we've got to work on preventing trauma and crisis," Ms Goward said.

"It's a very big change from the way these organisations have dealt with trauma to say: 'We know that there's going to be trauma. You will see terrible things that you won't be able to get out of your mind and there will be calls for help that you won't be able to answer and we know that's going to have an impact on you. And this is the way we want you to deal with it.'"

UNSW Associate Professor Samuel Harvey, who is based at the Black Dog Institute, developed the strategy with the aim to reduce the number of first responders who became unwell while ensuring there were systems to help those that did.

The whole field of psychiatry was moving towards the concept of prevention in the same way that cardiovascular medicine had done decades ago, he said.

"First responder organisations are by their nature responsive to crisis, so what used to happen is they used to respond once somebody became unwell," Associate Professor Harvey said

"But the document that's come out is drawing on what we can do to prevent people becoming unwell.

"Part of the problem is first responders are generally quite a tough and resilient group, so it's taken a while for there to be a culture for first responders to be able to discuss these symptoms."

One in 10 emergency workers were estimated to be living with post traumatic stress syndrome.

The emergency services had become increasingly aware of mental health issues as the costs associated with them had increased, Associate Professor Harvey said.

"The thing that differentiates first responders from most groups is the type of trauma that they're exposed to as a part of their day-to-day work.

"Sometimes it's a direct threat - the risk of being injured or killed - and other times it's them seeing the suffering of other people."

The emergency services in NSW have not always been known for their pastoral care when it comes to their employees, with tales past of officers told to drown their sorrows when things got tough.

No More Neglect - a noisy campaign to improve mental health support for ambulance employees co-ordinated by the former paramedic Steve McDowell - has chronicled dozens of stories in which management has failed to help people with mental health issues.

But Australian Paramedic Association NSW president Steve Pearce said NSW Ambulance had become more proactive in dealing with mental health in response to these issues being exposed.

"There was a long period of time where there was very little in the way of support from Ambulance but probably in the last two years, with a significant increase in media around post traumatic stress, they have increased their assistance," Mr Pearce said.

"We would like to see a dedicated unit rather than a couple of psychologists."

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