These events are devastating in themselves and will be the drivers of mental health issues, but psychologists and health groups are warning that there is a real danger of an increased level of post traumatic stress disorder (PTSD) that can be set off by these crises.

Professor Reg Nixon from the Flinders Posttraumatic Stress Research Unit said COVID-19 was likely to see people developing PTSD.

"Frontline staff are vulnerable. We have people dying, and paramedics, doctors and nurses having to make very difficult decisions about whose lives are in danger," Prof Nixon said.

"But, while events like bushfires or the pandemic can be very traumatic in themselves, we are aware they can be the catalyst that brings prior traumatic experiences to the surface," he said.

"They can be the straw that breaks the camel's back, a reminder of other losses, other traumatic experiences in a person's past.

"You can have a situation such as the recent police deaths in Melbourne in which fellow officers and first responders are obviously directly affected, but it can be that an event like this can trigger responses from people who were not at the scene or didn't know those officers personally.

Such an event can be a reminder of other losses, other traumatic experiences during their service that they might have been able to keep a lid on at the time, but something like this happens, unresolved issues come to the surface and it's the final straw.

"Everybody's got a breaking point.

"People come in with PTSD symptoms related to a current event but sometimes we find that there are traumas from a previous example that are resurfacing."

The Posttraumatic Stress Research Unit at Flinders University is working towards developing a more personalised and flexible form of Cognitive Processing Therapy (CPT) to assist the recovery of accident first respondents and military veterans suffering from posttraumatic stress disorder (PTSD).

"CPT was designed to help people recover after experiencing a traumatic event and has been widely used with veterans, military personnel and first responders - but we believe it can be further improved to deliver better outcomes,"

"Some clients were not responding to treatment as well as we would like, so we are now testing the helpfulness of closer monitoring during the early weeks of the CPT process, combined with making appropriate adjustments," Professor Nixon said.

Military veterans and accident first respondents suffering from PTSD will receive up to 25 individual therapy sessions of flexible CPT, all with a trained therapist. Usually in person, these are currently delivered via telehealth.

The second project is seeking volunteers to test a stepped-care approach delivered online and personalised through web-based camera therapy, making it attractive for patients in remote areas or who prefer not to attend in-person appointments.

This study - 'Online stepped-care for adults with PTSD' - is investigating a staged approach to help people recover after experiencing a traumatic event. Participants need to have been directly or indirectly exposed to a traumatic event such as assault, motor vehicle accident or childhood trauma, and should meet the threshold for PTSD.

Therapy involves working through eight weekly topics together with weekly online contact with a therapist, followed by up to 15 individual therapy sessions of CPT (60min each) also delivered online to address remaining PTSD issues.

Symptoms of PTSD include experiencing distressing and unwanted memories, avoiding feelings and reminders of the trauma, having strong negative thoughts such as self-blame, feeling frequently on high alert and unsafe, or having problems with sleep, anger or concentration.

Professor Nixon said obtaining treatment for PTSD ripples through communities.

"When someone recovers from PTSD, the benefits extend to those who are close to them, for example, family and friends, as the person is now in a better space.

"People are also more productive at work and more engaged members of the community."

Find out more or join the trials by going to this website.