It can be one big event or a million smaller ones that send people over the edge, and for emergency service workers the stress makes them more susceptible to mental illnesses, specifically Post-Traumatic Stress Disorder.

Many try to fight it alone, too ashamed to admit their problems or unable to recognise their own deteriorating condition.

But it is rarely a singular battle. Family and friends suffer as the victim withdraws or lashes out at those who are closest.

Angry, emotional and frustrated victims can start to play the blame game – with violent consequences.

There are broken dreams, broken relationships, lost careers and in some cases broken bones. But there is also hope as we start to understand that mental illness is a condition, not a character flaw.

Tuesday is Police Remembrance Day and there will be ceremonies around the country for the hundreds of police who lost their lives on duty. But there are no plaques for the thousands who gave their mental health.

TO be honest it was never a great marriage, although it was a functioning one – that is until the policeman saw one too many bodies.

For more than 20 years he chose to work in the clinical side of policing, which put him into contact with the most awful scenes –murders, suicides, crashes and bushfires.

Always quiet, he became more reserved, and like many police refused to discuss his cases at home until it all came crashing down at one crime scene.

"He said he nearly fainted and fell into the grave," his wife, "Louise" said.

When they shared a bed together – and that was some time ago – "I would wake and he would be sobbing in his sleep. It was after the bushfires (Black Saturday, February 2009)."

After a series of attempts to take his own life, the officer was hospitalised and is now retired as medically unfit. Eventually he enrolled in the Psychological Trauma Recovery Service 10-week program at the Heidelberg Repatriation Hospital for police, fellow emergency service workers and Australian Defence Force personnel.

As part of the program, spouses are invited to a five-week version. Louise says there were nine wives in her course. Eight suffered some form of family emotional or physical violence from threats to kill to being pushed down the stairs. "We found all the men with PTSD became very controlling."

"It is like walking on eggshells. You learn to pick the moods when they walk in the door."

He withdrew further and on a typical night would ask what was for dinner, eat in silence and then go to bed.

Dr Kevin Gilmartin, a 20-year United States police veteran and clinical psychologist writes in his book Emotional Survival For Law Enforcement, that police families often carry the burden of work stress.

He concludes that police invest he says, "Cynicism, anger, isolation and social distrust affect too many police homes."

He says suffering police who are active at work may be the opposite at home, becoming, tired, detached, isolated, apathetic and angry.

When Gilmartin asked one police spouse how many children she had she responded, "Including my husband?"

Louise agrees, "I should have adopted him, not married him."

They live pretty much separate lives now. "I tried so hard to be supportive but I don't have the answers," she says.

How much of their problems come from the slow, irretrievable breakdown of the marriage and how much is due to work-related stress is impossible to tell, but as Louise says, "It destroyed my family's life, destroyed what was left of my husband's mental health and has largely destroyed my marriage."

Could it be that for the PTSD sufferer who has seen so much violence in their career the very sort of criminal activity they policed for so many years is somehow normalised?

One policeman told Gilmartin, "I guess I love my family but I can't really stand being there. I walk into the house and realise, man I don't want to be here. It's not something I can put my finger on. I'm just not happy at home. I get angry at everything and in my mind nobody can do anything right. I just want to be left alone. At home they really make me crazy."

The co-ordinator of the Retired Peer Support Officer Program, Vicki Key says family violence is becoming a common theme with former police suffering depression, PTSD and other mental illnesses.

"We have cases of emotional abuse, controlling behaviour, stalking, assaults and instances when intervention orders have been taken out by wives and former wives."

Since October last year the program has had 139 contacts with former members suffering PTSD who are not coping and in a significant number of cases there has been some form of family violence.

"We have found that often the wives are the forgotten victims. We have been working with some wives to make sure they have safety plans in place," Key, a former police officer, says.

"We know of cases where sufferers have gone off their meds and are doctor-shopping. They have become hyper-vigilant and controlling. Wives and ex-wives have been followed and are vulnerable.

"They are fearful and many cases follow the same script. It is happening so often we see it as a core event."

She says spouses often don't know where to find help and are too embarrassed to go to the police for help. "The wives are trying to hold onto what remains of their marriages."

More than one spouse has reported being told by the sufferer, "If you don't do what I say, I'll kill myself."

Many who have been through the experience, she says, are now hyper-vigilant and suspicious of police, which is why they use ex-members as peer support officers.

"We have seen cases where former police have gambled their superannuation away and in other cases of substance abuse with prescription medications or a bottle of scotch a night."

This reporter has seen the consequences of PTSD with former police suffering and several choosing to take their own lives.

In one case the former head of a high-profile taskforce killed a neighbour before turning the gun on himself. Another involved in a marriage breakup took his own life. Police heroes who have run off the rails have been quietly sacked, or in some cases, jailed.

According the the Department of Veterans' Affairs, "The symptoms associated with PTSD (intrusive memories, hyperarousal and avoidance) can lead to particular difficulties in family relationships. Hyperarousal can contribute to aggression and domestic violence."

According to PTSD expert Dr Matthew Tull "People with PTSD have also been found to be more likely to be aggressive and engage in intimate partner abuse than people without a PTSD diagnosis. The connection between PTSD and violence has been found for both men and women with PTSD.

One policeman quit shortly after, "I woke up one night and the missus was crying. I asked why and she said I tried to strangle her in my sleep. I was forever fighting the pillow."

The police department and police association are looking at ways to re-engage with former members battling mental health issues.

Many of his former mates were shocked to find a popular colleague who fell off the radar died in squalid conditions as a hermit –  estranged from family and friends.

Mrs Key says they have found two homeless police and another three living in a notorious boarding house.

Beyondblue Chairman Jeff Kennett has been driving nationwide research on mental health issues involving emergency first responders.

He says there are three groups – serving responders, former members and their families.

There are about 2500 Retired Police Association members, while more than 10,000 ex-police have not joined and are lost to the system.

Kennett says one concept under proposal is to set up clubs where ex-emergency service workers can meet, possibly in connection with the RSL.

An external police research project set up by former chief commissioner Ken Lay into police suicides and depression is due to be completed soon after it has become clear that many in crisis are concealing their illnesses because they fear their careers will be damaged if they seek in-house treatment.

In 2014 a total of 23 operational police and six police public servants had taken their own lives since 1995.

Police records show none sought assistance from internal welfare experts despite an ongoing police mental health awareness program. Some police who have declared stress-related illness say they feel they were forced out of the job they loved.

Others who sort compensation say they felt bullied by a process that only added to their stress. For help or information, call Lifeline 131 114, beyondblue 1300 224 636 or Retired Peer Support Officer at rpsoprogram@gmail.com.