Lucan · Conditions

Post-traumatic stress disorder

Australian guidance: RACGP Stress-Related Disorders Following Trauma + Phoenix Australia

1. Definition and epidemiology

Post-traumatic stress disorder (PTSD) is a psychiatric disorder arising after direct or indirect exposure to actual or threatened death, serious injury, or sexual violence, characterised by intrusive re-experiencing, avoidance, negative alterations in cognition and mood, and hyperarousal persisting beyond one month. The lifetime prevalence in Australia is approximately 7 to 12 percent of the general population, with higher rates among emergency service workers, defence force personnel, and survivors of sexual assault. Women are approximately twice as likely as men to develop PTSD following trauma exposure, and First Nations Australians face elevated rates linked to intergenerational and ongoing traumatic stressors.

2. Pathophysiology

PTSD involves dysregulation of the threat-response circuitry anchored in the amygdala, prefrontal cortex (PFC), and hippocampus. Traumatic stress activates the hypothalamic-pituitary-adrenal (HPA) axis acutely, releasing cortisol and adrenaline. In individuals who develop PTSD, subsequent HPA axis dysregulation produces low baseline cortisol with exaggerated reactivity, impaired glucocorticoid negative feedback, and heightened noradrenergic tone via the locus coeruleus. The amygdala becomes sensitised to threat-related cues, generating exaggerated fear responses, while hippocampal volume reduction (observed on structural magnetic resonance imaging) impairs contextual processing and extinction of fear memories. The medial PFC, which normally exerts top-down inhibition over the amygdala, shows reduced activation and reduced volume, preventing adequate fear extinction. This triad produces flashbacks, hyperarousal, and failure to distinguish past threat from present safety. Serotonergic and dopaminergic pathways contribute to mood and motivation deficits, and neuroinflammatory mechanisms including elevated interleukin-6 and tumour necrosis factor-alpha have been identified in chronic PTSD.

3. Clinical presentation and diagnostic criteria

DSM-5 requires all four symptom clusters to be present for at least one month following trauma exposure, causing clinically significant distress or functional impairment.

Cluster B (intrusion): recurrent involuntary distressing memories, nightmares, dissociative flashbacks, intense psychological distress or physiological reactivity on exposure to trauma cues. At least one criterion required.

Cluster C (avoidance): effortful avoidance of distressing trauma-related thoughts or feelings, and avoidance of external reminders such as people, places, conversations, or situations. At least one criterion required.

Cluster D (negative alterations in cognition and mood): inability to recall key aspects of the trauma, persistent negative beliefs about self or world, distorted blame of self or others, persistent negative emotion, diminished interest in significant activities, feelings of detachment, persistent inability to experience positive emotion. At least two criteria required.

Cluster E (alterations in arousal and reactivity): irritability or angry outbursts, reckless or self-destructive behaviour, hypervigilance, exaggerated startle response, concentration difficulties, sleep disturbance. At least two criteria required.

On examination, assess for comorbid major depressive disorder, alcohol and substance use disorders, chronic pain, traumatic brain injury, and suicide risk, as these are common and affect prognosis. A trauma-focused formulation includes the nature of the trauma, peritraumatic dissociation, prior trauma history, and available social support.

4. Investigations and AU-specific cutoffs

PTSD is a clinical diagnosis; no pathological test confirms it. However, the following are used in AU clinical practice.

Screening tools: the Primary Care PTSD Screen for DSM-5 (PC-PTSD-5) is a validated 5-item screen recommended in primary care by Phoenix Australia guidelines. A score of 3 or more out of 5 is considered positive and warrants further assessment. The PTSD Checklist for DSM-5 (PCL-5) is a 20-item self-report scale scored 0 to 80; a provisional PTSD diagnosis is suggested at 31 to 33 or above depending on the setting, with Phoenix Australia recommending 33 as a cut-off in civilian populations.

Baseline investigations are directed at ruling out organic contributors and screening for comorbidities: full blood count, thyroid-stimulating hormone (TSH), liver function tests (LFTs) and gamma-glutamyl transferase (GGT) if alcohol use is suspected, urine drug screen, and a baseline metabolic panel before starting pharmacotherapy.

Brain imaging is not routinely required but may be considered when traumatic brain injury is suspected or when the clinical presentation is atypical.

5. Management

Management follows a stepped-care model per Phoenix Australia and RACGP guidance. Watchful waiting with psychoeducation and safety planning is appropriate for mild symptoms of less than one month duration. For symptoms persisting beyond one month with moderate to severe functional impairment, active treatment is indicated.

Trauma-focused psychological therapies are the first-line treatment, with the strongest evidence base in Australian and international guidelines. Trauma-focused cognitive behavioural therapy (TF-CBT), prolonged exposure (PE), and cognitive processing therapy (CPT) each carry strong recommendations. Eye movement desensitisation and reprocessing (EMDR) is also strongly recommended by Phoenix Australia. These are delivered by trained psychologists or psychiatrists, typically over 8 to 16 sessions. Access via Medicare Better Access (Mental Health Treatment Plan, up to 20 sessions per calendar year) is the primary pathway in primary care.

For complex or treatment-resistant presentations, stabilisation-focused interventions addressing emotion regulation are delivered prior to trauma processing. Referral to a specialist service (community mental health, veteran-specific services such as Open Arms or the Department of Veterans Affairs network for eligible personnel) is indicated when first-line therapies fail, when there is significant comorbidity, or when suicidality is present.

Brief interventions during the acute stress period within the first month should focus on psychological first aid and social support rather than single-session debriefing, which Phoenix Australia does not recommend as it does not prevent PTSD.

6. Pharmacology and AU PBS notes

Pharmacotherapy is second-line in PTSD, used when psychological therapies are unavailable, declined, or insufficient. It can be used adjunctively with psychological therapy.

First-line agents are selective serotonin reuptake inhibitors (SSRIs). Sertraline (Zoloft, generics) and paroxetine (Aropax, generics) have the best evidence base for PTSD; sertraline is the preferred AU first-line agent. Starting dose is sertraline 25 mg daily, titrating to 50 to 200 mg daily over two to four weeks. PBS: sertraline is listed on the PBS for depression (streamlined code 4145) and is prescribed off-label for PTSD in Australia. Paroxetine 20 to 60 mg daily is an alternative.

Second-line agents include the serotonin-noradrenaline reuptake inhibitor (SNRI) venlafaxine (Efexor XR) 75 to 225 mg daily, which has moderate evidence for PTSD and is used when SSRIs are not tolerated. Mirtazapine (Avanza) 15 to 45 mg nightly may be used adjunctively for sleep and appetite disturbance.

Prazosin (Minipress) 1 to 10 mg nightly is used for trauma-related nightmares, particularly in veterans; evidence from AU clinical practice aligns with international guidance though it is not PBS-listed for this indication.

Benzodiazepines are not recommended for PTSD as they may impair fear extinction and are associated with worse outcomes, increased substance use risk, and dependence; RANZCP guidance specifically cautions against their routine use.

Antipsychotics are not first or second-line; quetiapine or risperidone may be considered by specialists for severe hyperarousal or psychotic features.

7. Complications and monitoring

Comorbid major depressive disorder occurs in approximately 50 percent of patients with PTSD and increases suicide risk substantially. Suicidality must be assessed at every clinical contact using structured tools (Columbia Suicide Severity Rating Scale, C-SSRS) or the standardised GP risk assessment.

Alcohol and substance use disorders co-occur in approximately 30 to 50 percent of people with PTSD in Australia; screen with AUDIT-C and brief intervention at every contact. Substance use that continues alongside PTSD treatment worsens prognosis and requires integrated dual-diagnosis management.

Chronic pain, somatic symptoms, and medically unexplained symptoms are frequently comorbid, especially in trauma survivors with physical injury.

Cardiovascular risk is elevated in chronic PTSD due to persistent noradrenergic activation, poor sleep, and lifestyle factors; annual metabolic monitoring (blood pressure, fasting glucose, lipids, body mass index) is recommended.

Treatment response should be reviewed at four to six weeks after initiating pharmacotherapy and at completion of each psychological therapy course, using PCL-5 scores to track change. Partial or non-response warrants dose optimisation, switching agent or modality, or specialist referral. Long-term follow-up is indicated as relapse is common, particularly during periods of increased stress or trauma anniversary dates.

Written for Australian practice and grounded in the guidance named above. Study material only — not medical advice. Always check against current guidelines.