Understanding PTSD: When the Past Keeps Arriving in the Present

Most people will experience distressing or overwhelming events at some point in their lives.

These may include accidents, sudden loss, assault, family violence, sexual assault, life-threatening illness, natural disasters, war, or workplace trauma, including repeated exposure through roles in emergency services, health care, policing, journalism or military service.

A traumatic event is more than ordinary stress. It usually involves actual or threatened death, serious injury, sexual violence, or a profound threat to physical or psychological safety. Trauma can happen directly to us, we can witness it happening to someone else, or we can be repeatedly exposed to traumatic material through our work.

Many people recover after trauma with time, safety, support and connection. They may still feel changed by what happened; perhaps more cautious, more aware of risk, or less certain that the world is always safe. But gradually, the traumatic event becomes part of their past rather than something that keeps intruding into the present.

Post-Traumatic Stress Disorder, or PTSD, can develop when this natural recovery process gets stuck. PTSD is not a sign of weakness, and it is not a failure of resilience. It is an understandable and treatable response to an overwhelming experience.

How common is PTSD?

Trauma exposure is common, but PTSD is not inevitable. Australian data suggests that around three-quarters of Australian adults have experienced a traumatic event at some point in their lives, yet most do not go on to develop PTSD.

Data from the National Study of Mental Health and Wellbeing indicates that approximately 5.6% of Australian adults experienced PTSD in the previous 12 months. The Australian Institute of Health and Welfare reports that around 11% of Australians experience PTSD at some point in their lifetime.

This distinction matters.

Many people have strong reactions in the early days and weeks following trauma. Sleep disruption, shock, tearfulness, numbness, intrusive images, anger, fear, or feeling constantly on edge are all common early responses. For most people, these reactions gradually settle.

PTSD is diagnosed when trauma symptoms persist and significantly interfere with life, relationships, work, study, sleep or wellbeing.

Understanding PTSD: The four core symptom clusters

To understand PTSD is to recognise that at its heart, PTSD is a condition in which the brain and body have difficulty fully registering that the traumatic event is over. People often describe knowing rationally that they are safe now, while their body reacts as though the danger is still happening.

PTSD symptoms are generally grouped into four main areas.

1. Re-experiencing symptoms

The trauma keeps breaking into everyday awareness in unwanted and distressing ways. This is not just “thinking about” the event. It can feel as though the person is back there entirely, or in part.

Re-experiencing symptoms may include:

• intrusive memories or nightmares

• flashbacks, where a person may see, hear, smell or feel things connected to the trauma

• intense emotional or physical distress when encountering reminders

• sudden waves of panic, shame, disgust or dread

Not everyone has vivid visual flashbacks. For some people, trauma is re-experienced through body sensations, emotional states, sounds, smells, images or a sudden sense of threat.

2. Avoidance symptoms

Because trauma reminders can trigger intense distress, avoiding them is a natural survival strategy. However, over time, avoidance can keep PTSD going by preventing the brain and body from learning: “That was then. This is now. I survived.”

Avoidance may include:

• avoiding places, conversations or people connected to the event

• steering clear of internal triggers such as specific emotions, thoughts or body sensations

• avoiding medical appointments, driving, crowds, intimacy, news stories or certain work tasks

Avoidance often makes sense in the short term. Therapy can help people gradually and safely reduce avoidance so that life becomes less restricted by fear.

3. A persistent sense of threat

In PTSD, the body’s threat system can become highly sensitive. It may operate as though danger could return at any moment, even when the person is now safe.

This may include:

• feeling constantly on edge or easily startled

• hypervigilance, such as scanning rooms for exits or sitting with your back to the wall

• irritability, sudden anger or difficulty concentrating

• physical tension, sleep disturbance, racing heart, nausea or shakiness

This is not “overreacting”. It is the body trying to protect the person after trauma, but doing so long after the immediate danger has passed.

4. Changes in mood, thinking and connection

Trauma can affect how a person views themselves, other people and the future. These symptoms can be particularly painful because they can affect identity, trust and close relationships.

This may include:

• persistent guilt, shame or self-blame

• emotional numbness or difficulty feeling positive emotions

• loss of interest in previously enjoyed activities

• difficulty trusting others or feeling detached from loved ones

• a sense that the world is unsafe or that the future has narrowed

A person may not simply feel frightened. They may feel changed, distant from themselves, or unsure how to return to ordinary life.

Diagnostic criteria for PTSD: DSM-5-TR and ICD-11

Clinicians use two major international diagnostic systems to diagnose PTSD: the DSM-5-TR and the ICD-11. Both require that symptoms cause significant distress or impairment, but they organise PTSD symptoms slightly differently.

Diagnostic system	Core approach	Symptom groups
DSM-5-TR	A broad framework for understanding trauma’s psychological impact.	Four clusters: intrusion/re-experiencing, avoidance, negative changes in mood and thinking, and changes in arousal and reactivity.
ICD-11	A narrower framework focused on core PTSD features.	Three groups: re-experiencing the trauma in the present, avoidance of traumatic reminders, and a persistent sense of current threat.

In both systems, PTSD is not diagnosed simply because someone has experienced trauma. It is diagnosed when trauma symptoms persist and interfere with the person’s life.

PTSD is not the only response to trauma

Not all distress after trauma is PTSD. People may also experience grief, depression, generalised anxiety, panic, substance use difficulties or moral injury. These difficulties can occur alongside PTSD or separately from it.

Some people develop Complex PTSD, particularly after repeated, prolonged or interpersonal trauma, such as childhood abuse or ongoing family violence. Complex PTSD includes the core features of PTSD alongside persistent difficulties with emotion regulation, self-worth and relationships.

A careful clinical assessment can help clarify what is happening and what kind of support is likely to be most useful.

What helps after trauma?

In the immediate aftermath of trauma, forced psychological debriefing is not recommended. Instead, modern guidelines emphasise practical safety, emotional support, connection with trusted people, accurate information and a sense of choice and control.

A trauma-informed approach is important if a person seeks psychological treatment shifts the question from “What is wrong with you?” to “What happened to you, what has helped you survive, and what do you need now?”. Finding safety and stability is key in this approach.

This is especially important after interpersonal trauma, such as sexual assault or family violence. Good trauma-informed care respects the person’s dignity, autonomy and pace. It does not require someone to disclose every detail before they feel ready.

Evidence-based psychological therapies

When PTSD symptoms persist, Australian and international guidelines recommend trauma-focused psychological therapies as first-line treatments.

These include:

• trauma-focused cognitive behavioural therapy

• cognitive processing therapy

• prolonged exposure therapy

• trauma-focused cognitive therapy

• Eye Movement Desensitisation and Reprocessing, or EMDR therapy

These therapies differ in method, but they share a common goal: helping the brain and body process the traumatic memory so that it becomes part of the past, rather than something that keeps intruding into the present.

Good trauma therapy is collaborative, transparent and carefully paced. The person remains in control of the focus and speed of treatment. Therapy should not force people to “just talk about it” before they feel ready.

Recovery is possible

Recovery does not mean forgetting what happened. It means the memory loses some of its raw physical and emotional intensity. It becomes less likely to trigger the body’s alarm system, shape the person’s choices, or narrow their life.

The trauma may remain a painful part of the person’s story. But with skilled, compassionate and evidence-based care, it does not have to define the rest of their life.

References

• Australian Bureau of Statistics. (2023). National Study of Mental Health and Wellbeing, 2020–2022.

• Australian Institute of Health and Welfare. (2025). Stress and trauma: Mental health topic area.

• Phoenix Australia. (2020). *Australia

• Guidelines for the Prevention and Treatment of Acute Stress Disorder, Posttraumatic Stress Disorder and Complex PTSD.*

• Phoenix Australia. (2022). Recovery after Trauma: A Guide for People with Posttraumatic Stress Disorder.

• World Health Organization. (2022). ICD-11: International Classification of Diseases, 11th Revision.

The team at Melbourne Psychology & Counselling includes psychologists with special interest in PTSD and all clinicians are trauma informed therapists. You can learn more about our approach via contact us directly.