TextbookPsychiatry & Mental HealthPost-Traumatic Stress Disorder

Post-Traumatic Stress Disorder

PTSD develops after exposure to a traumatic event, characterised by re-experiencing, avoidance, negative cognitions, and hyperarousal. Prevalence is approximately 3-4% in the UK.

Key Facts

PTSD develops after exposure to actual or threatened death, serious injury, or sexual violence — directly, witnessed, or learned about Symptoms must persist for >1 month after the traumatic event; onset within 6 months in most cases Four symptom clusters: Re-experiencing (flashbacks, nightmares), avoidance, negative cognitions/mood, hyperarousal First-line treatment: Trauma-focused CBT or EMDR (NICE NG116) Drug treatment is second-line: Venlafaxine 75-150mg or SSRI (sertraline, paroxetine) if psychological therapy declined or not available Single-session debriefing is NOT recommended — no evidence of benefit and may be harmful Complex PTSD (ICD-11): PTSD symptoms plus disturbances in self-organisation (affect dysregulation, negative self-concept, interpersonal difficulties) — typically follows prolonged/repeated trauma Approximately 20-30% of people exposed to trauma develop PTSD; risk factors include female sex, previous trauma, peritraumatic dissociation

Overview

Key Facts

PTSD is a trauma and stress-related disorder that develops following exposure to an exceptionally threatening or horrifying event. It causes significant psychological distress and functional impairment through four core symptom clusters.

Epidemiology

Lifetime prevalence in the UK is approximately 3-4%. Higher in military personnel (~6-17%), emergency service workers, and refugees. Women are approximately twice as likely to develop PTSD as men. Median time to treatment is 12 years.

Aetiology

  • Traumatic events: Combat, assault, rape, accidents, natural disasters, terrorism, childhood abuse
  • Risk factors: Female sex, prior psychiatric history, childhood adversity, peritraumatic dissociation, lack of social support, repeated trauma
  • Protective factors: Social support, resilience, higher education, adaptive coping

Pathophysiology

  • Fear conditioning: Amygdala hyperactivation — traumatic cues trigger exaggerated fear response
  • Hippocampal dysfunction: Impaired contextualisation of memories — explains flashbacks (memories experienced as current events)
  • Prefrontal cortex hypofunction: Failed top-down regulation of amygdala
  • HPA axis dysregulation: Paradoxically LOW cortisol in PTSD (unlike depression) — enhanced negative feedback
  • Noradrenergic hyperactivity: Locus coeruleus overactivity → hyperarousal, exaggerated startle
  • Memory consolidation: Traumatic memories poorly integrated into autobiographical memory — remain "unprocessed" and intrusive

Clinical Presentation

Re-experiencing

  • Flashbacks: Vivid, involuntary reliving of the trauma (as if happening now)
  • Nightmares: Distressing dreams of the event
  • Intrusive memories: Unwanted, distressing recollections
  • Psychological/physiological reactivity to trauma reminders

Avoidance

  • Avoidance of thoughts, feelings, or conversations about the trauma
  • Avoidance of people, places, activities that trigger memories

Negative Cognitions and Mood

  • Persistent negative beliefs ("I am broken," "The world is dangerous")
  • Distorted blame of self or others for the trauma
  • Persistent negative emotional state (fear, horror, anger, guilt, shame)
  • Diminished interest in activities, detachment from others

Hyperarousal

  • Hypervigilance, exaggerated startle response
  • Irritability, anger outbursts
  • Difficulty concentrating
  • Sleep disturbance
  • Reckless or self-destructive behaviour

Red Flags

  • Suicidal ideation — PTSD has significant suicide risk (~5-10× general population)
  • Substance misuse — very common comorbidity (self-medication)
  • Dissociative symptoms — depersonalisation/derealisation variant
  • Complex PTSD — requires longer, phased treatment approach

Differential Diagnosis

DiagnosisKey FeaturesInvestigation
Acute stress disorderSimilar symptoms but <1 month after traumaClinical assessment
Adjustment disorderSymptoms disproportionate to stressor but don't meet PTSD criteriaClinical assessment
DepressionLow mood, anhedonia without specific re-experiencingPHQ-9
GADChronic worry about multiple concerns, not trauma-specificGAD-7
Panic disorderRecurrent panic attacks, not trauma-triggeredClinical history
Borderline personality disorderChronic mood instability, self-harm, identity disturbanceLongitudinal assessment
Traumatic brain injuryCognitive symptoms, trauma history, no re-experiencingNeuroimaging, neuropsychology

Diagnosis / Investigation

Bedside

  • PCL-5 (PTSD Checklist): 20-item self-report measure aligned with DSM-5
  • IES-R (Impact of Event Scale-Revised): Screening tool
  • PHQ-9, GAD-7: Comorbid depression and anxiety screening
  • AUDIT-C: Alcohol misuse screening
  • Risk assessment: Comprehensive — suicide, self-harm, violence

Bloods

  • TFTs: Exclude thyroid dysfunction
  • FBC, LFTs: Baseline and alcohol-related complications
  • Drug screen: If substance misuse suspected

Special Tests

  • Structured clinical interview: CAPS-5 (Clinician-Administered PTSD Scale) — gold standard diagnostic tool
  • Neuroimaging: Not routine — research shows reduced hippocampal volume, amygdala hyperactivity

Management

Non-pharmacological (NICE NG116)

  • Active monitoring: For mild symptoms <4 weeks post-trauma — many improve spontaneously
  • Trauma-focused CBT: First-line — 8-12 sessions; includes trauma narrative, cognitive restructuring, in-vivo exposure
  • EMDR (Eye Movement Desensitisation and Reprocessing): First-line — 8-12 sessions; bilateral stimulation during trauma memory processing
  • NOT recommended: Single-session psychological debriefing

Pharmacological (NICE NG116)

  • Second-line (if psychological therapy declined, not available, or not effective):
    • Venlafaxine 75-150mg OD
    • SSRI: Sertraline 50-200mg OD or paroxetine 20-50mg OD
  • Prazosin 1-15mg ON: For PTSD-related nightmares (alpha-1 blocker, off-label)
  • Not recommended: Benzodiazepines (may worsen PTSD, impair extinction learning)
  • Treatment duration: Continue for ≥12 months; gradual tapering

Referral Criteria

  • PTSD symptoms >1 month — psychological therapy referral (IAPT or specialist trauma service)
  • Complex PTSD — specialist trauma service
  • Treatment-resistant PTSD — secondary care psychiatry
  • Significant comorbidity — MDT approach
  • Military veterans — Op COURAGE (NHS Veterans' Mental Health service)

Prognosis

  • Natural course: ~50% recover within 3 months; ~30% have chronic course
  • Trauma-focused CBT: ~60-70% response rate; gains well-maintained
  • EMDR: Similar efficacy to trauma-focused CBT
  • Chronic PTSD (>1 year): Poorer prognosis; may require longer treatment
  • Complex PTSD: Requires phased treatment (stabilisation → trauma processing → reintegration); longer duration
  • Comorbidity: ~80% have at least one comorbid condition (depression, anxiety, substance misuse)
  • Suicide: PTSD increases suicide risk ~5-10×; comprehensive risk management essential

Other Relevant Information

ICD-11 Complex PTSD

Core PTSDPlus Disturbances in Self-Organisation
Re-experiencingAffect dysregulation (emotional reactivity, dissociation)
AvoidanceNegative self-concept (worthlessness, shame, guilt)
HyperarousalInterpersonal difficulties (detachment, distrust)

PTSD Risk Factors

FactorEffect
Female sex2× risk
Prior psychiatric historyIncreased risk
Peritraumatic dissociationStrong predictor
Lack of social supportIncreased risk
Severity/duration of traumaDose-response relationship
Childhood adversityIncreased risk for complex PTSD