Clinical Review

Post-traumatic stress disorder

BMJ 2015; 351 doi: (Published 26 November 2015) Cite this as: BMJ 2015;351:h6161
  1. Jonathan I Bisson, professor of psychiatry,
  2. Sarah Cosgrove, public representative,
  3. Catrin Lewis, research psychologist,
  4. Neil P Roberts, consultant clinical psychologist
  1. 1Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
  1. Correspondence to: J I Bisson BissonJI{at}

What you need to know

  • Individual reactions to traumatic events vary greatly and most people do not develop a mental disorder after exposure to trauma

  • PTSD should be considered in any patient exposed to a major traumatic event

  • Up to 3% of adults has PTSD at any one time. Lifetime prevalence rates are between 1.9% and 8.8%

  • Psychological treatments, particularly trauma focused psychological therapies, can be effective

  • Although the effect sizes are not as high as for psychological therapies, drug treatments can be effective

  • Patients with complex PTSD should receive specialist multidisciplinary care

What is post-traumatic stress disorder (PTSD)?

PTSD is a mental disorder that may develop after exposure to exceptionally threatening or horrifying events. Many people show remarkable resilience and capacity to recover following exposure to trauma.1 PTSD can occur after a single traumatic event or from prolonged exposure to trauma, such as sexual abuse in childhood. Predicting who will go on to develop PTSD is a challenge.2


Examples of the many different trajectories of PTSD symptoms after exposure to trauma

Sources and selection criteria

We identified Cochrane and other relevant systematic reviews and meta-analyses, and supplemented these with additional searches and our knowledge of the subject. Wherever possible, we used evidence from recent meta-analyses of randomised trials.

Patients with PTSD are at increased risk of experiencing poor physical health, including somatoform, cardiorespiratory, musculoskeletal, gastrointestinal, and immunological disorders.3 4 It is also associated with substantial psychiatric comorbidity,5 increased risk of suicide,6 and considerable economic burden.7 8

PTSD is a widely accepted diagnosis9 but some believe that the term medicalises understandable responses to catastrophic events and further disempowers those who are already disempowered.10

How common is PTSD?

About 3% of the adult population has PTSD at any one time.11 Lifetime prevalence is between 1.9%12 and 8.8%,7 but this rate doubles in populations affected by conflict13 and reaches more than 50% in survivors of rape.5

How does PTSD present?

Symptoms include persistent intrusive recollections, avoidance of stimuli related to the trauma, negative alterations in cognitions and mood, and hyperarousal (table).14 15 A diagnosis can be made in someone whose ability to function normally has been noticeably impaired for one month according to DSM-5 criteria. Delayed presentation (sometimes years later) is common,7 including where the effects are severe.16

Symptoms required for diagnosis of PTSD

View this table:

How is PTSD diagnosed?

Box 1 describes the nature of the traumatic event(s) required by DSM-5 (diagnostic and statistical manual of mental disorders, fifth edition)14 for diagnosis and the proposed criteria by ICD-11 (international classification of diseases, 11th revision).17 Some events such as bullying, divorce, death of a pet, and learning about a diagnosis of cancer in a close family member are not deemed extreme enough to precipitate PTSD. However, they can result in almost identical symptoms and raise questions about the validity of the definitions for traumatic events.18

Box 1 Traumatic event(s) required for diagnosis of PTSD

DSM-5 criteria[14]
  • Exposure to actual or threatened death, serious injury, or sexual violation, in one or more of the following ways:

    • Directly experiencing the traumatic event(s)

    • Witnessing traumatic event(s) in others

    • Learning that the traumatic event(s) occurred to a close family member or close friend; cases of actual or threatened death must have been violent or unintentional

    • Experiencing repeated or extreme exposure to aversive details of the traumatic event(s) (for example, first responders collecting human remains; police officers repeatedly exposed to details of child abuse); this does not apply to exposure through electronic media, television, movies, or pictures, unless this exposure is work related

Proposed ICD-11 criterion[17]
  • Exposure to an extremely threatening or horrific event or series of events

DSM-5 lists the 20 symptoms required for PTSD to be diagnosed,14 separated into four groups (table). All symptoms must be associated with the traumatic event. In the proposed criteria by ICD-11,17 PTSD will be diagnosed according to six criteria (table). To reflect the heterogeneity of PTSD, ICD-11 will introduce a new complex PTSD diagnosis (table). This requires satisfaction of the criteria for PTSD plus symptoms of mood dysregulation, negative self concept, and persistent difficulty in sustaining relationships and feeling close to others. Service users may meet the diagnostic criteria in one system but not in the other owing to the differences.19

Can PTSD be prevented?

Psychological interventions

Psychological interventions have been evaluated after traumas concerning a single incident, such as a road traffic crash and physical or sexual assaults. Meta-analyses show that brief, trauma focused, cognitive behavioural interventions can reduce the severity of symptoms when the intervention is targeted at those with early symptoms.20 21 However, non-targeted interventions (including psychoeducation, psychological debriefing, individual and group counselling, cognitive behavioural therapy (CBT) based programmes, and collaborative care based approaches) are largely ineffective.22 23 24 25

Drug interventions

No robust evidence supports the use of drug interventions.26

Prevention after large scale traumatic events

Evidence to support routine intervention after traumatic events involving many people (for example, terrorist attacks and natural disasters) is lacking. However, some evidence suggests that high levels of social support are perceived as protective.27 Consensus guidelines recommend supportive, practical, and pragmatic input but avoidance of formal clinical interventions unless indicated.28 29 30

Can PTSD be treated?

Psychological therapy

Clinical guidelines recommend trauma focused psychological therapies based on evidence from systematic reviews and meta-analyses.31 32 33 Individual trauma focused CBT and eye movement desensitisation and reprocessing (EMDR) (box 2) have been found to be equally effective.34

Box 2 Trauma focused exposure therapy, CBT and EMDR

Exposure therapy
  • Therapists help patients to confront their traumatic memories through written or verbal narrative, detailed recounting of the traumatic experience, and repeated exposure to trauma related situations that were being avoided or evoked fear but are now safe (for example, driving a car where the road traffic incident occurred or walking in the busy park where an assault occurred)

Cognitive therapy
  • Focuses on identifying and modifying misinterpretations that led patients to overestimate the current threat (for example, patients who think assault is almost inevitable if they leave the house)

  • Focuses on modifying beliefs and how patients interpret their behaviour during the trauma, including problems with guilt and shame

  • Standardised, trauma focused procedure. Involves the use of bilateral physical stimulation (eye movements, taps, or tones), hypothesised to stimulate the patient’s information processing to help integrate the targeted event as an adaptive contextualised memory

Group trauma focused CBT is also effective, but fewer studies have focused on this method.35 Non-trauma focused CBT—including components such as grounding techniques to manage flashbacks (for example, focusing on the here and now by describing items in a room), relaxation training (for example, controlled breathing and progressive muscle relaxation), positive thinking and self talk (for example, repeating positive phrases such as “I can deal with this”)—has been found to be superior to waiting list control groups and has shown similar efficacy to trauma focused CBT and EMDR immediately after treatment, but this is not maintained at follow-up.34 Non-trauma focused CBT offers a valid alternative to trauma focused therapy if the latter is poorly tolerated, contraindicated, or unavailable. It is unclear whether specific therapies are more or less effective for particular subgroups or trauma types.36 37

Research on interventions for more complex presentations of PTSD is limited.38 Evidence suggests that phased approaches may be beneficial for more complex presentations of PTSD.39 Phase based approaches target problems such as affect dysregulation, dissociation, and somatic symptoms to promote adaptive coping, a sense of safety, and stabilisation before undertaking any trauma focused intervention.

Self help programmes

Guided self help interventions for depression and anxiety disorders are being used as an alternative to face to face therapy as these interventions offer enhanced access to cost effective treatment.40 Some evidence suggests that internet based guided self help therapies effectively alleviate the symptoms of traumatic stress, but randomised controlled trials (RCTs) have historically been limited to subsyndromal populations.41 42 More recent evidence supports the efficacy of guided self help for people meeting diagnostic criteria for PTSD,43 44 45 but no head to head trials have compared guided self help with trauma focused psychological therapy administered by a therapist.

Drug treatment

The National Institute for Health and Care Excellence and World Health Organization recommend drug treatment second to trauma focused therapy.33 46 The effect sizes for drug treatments compared with placebo are inferior to those reported for psychological treatments with a trauma focus over waiting list or treatment as usual controls.33 47 Effect sizes with drug treatment are similar to those observed from use of antidepressants for depression compared with placebo.48 A recent systematic review and meta-analysis found statistically significant evidence (when at least two RCTs were available) of reduction in severity of PTSD symptoms for four drugs (fluoxetine, paroxetine, sertraline, and venlafaxine) versus placebo.47 In single RCTs, amitriptyline, GR205171 (a neurokinin-1 antagonist), mirtazapine, and phenelzine have shown superiority over placebo in reducing the symptoms of PTSD.

In an RCT the α 1 adrenoceptor antagonist prazosin was found to reduce nightmares in veterans with PTSD,49 and a further RCT in veterans showed reduction in overall symptom severity.50 This suggests a possible role for α 1 adrenoceptor blockers in PTSD, although further research is needed. Olanzapine, in contrast with another antipsychotic, risperidone, has been shown to accentuate the effects of antidepressants when resistance to treatment is encountered.51 52

Combination therapy

Evidence to support the use of pharmacotherapy combined with psychological therapy over either treatment method separately is insufficient.53

How should PTSD and comorbidity be managed?

PTSD is associated with depression, anxiety disorders, and drug and alcohol use disorders. Little evidence exists for the effectiveness of psychological interventions for PTSD with comorbid substance use disorders. Some evidence suggests that trauma focused CBT can be effective with concomitant interventions to stabilise drug or alcohol use, but treatment effects are not as large as for PTSD in the absence of drug or alcohol misuse.54

What is the prognosis in PTSD?

Few longitudinal follow-up studies have been done of PTSD, but for many patients PTSD is severe and enduring.5 There is, however, good evidence that patients may benefit from treatment even when the symptoms have been present for many years.34

Are there emerging options to prevent and treat PTSD?

Several experimental studies provide hope that better or alternative ways to prevent and treat PTSD are on the way. Simple visuospatial tasks such as playing a computer game shortly after a traumatic experience reduce re-experiencing.55 For established PTSD, interest in using drugs to augment psychological therapy is increasing. The results of a recent RCT of the psychedelic 3,4-methylenedioxymethylamphetamine with psychotherapy for treatment resistant PTSD have been promising.56 57 These approaches remain in their infancy, and further well designed clinical studies are required to determine if they will live up to their early promise.

How were patients involved in this clinical review?

Sarah Cosgrove is a former patient with PTSD and a representative of the public in Cardiff University’s Traumatic Stress Research Group. Sarah is a coauthor of the paper and provides an account of her experiences in the patient’s perspective box.

A patient’s perspective

I was diagnosed with PTSD in November 2013 in the aftermath of a violent assault. From the time of the attack to the case coming to court, I had support from police and victim services enabling me to face my assailant in court with courage and conviction.

But in the weeks after the judicial process had concluded, I started to unravel. Naturally a glass half full sort of person, I slid into a state of great anxiety, frightened to be alone, scared to be in a group, reluctant to go out, and terrified of staying at home. I knew something was very wrong. I had gone from being confident and outgoing, to not being able to sleep, being tearful, and experiencing episodes of unparalleled low mood. My GP immediately diagnosed PTSD. Being able to put a label on what I was going through was so helpful—it meant that there was something wrong.

Fortunately, I was offered the chance to participate in a trial of a guided self help programme for sufferers of PTSD. This enabled me to both confront my experience and desensitise it, and within a few months I felt stronger than I had ever been. The programme has given me a coping strategy to employ whenever I get negative thoughts or flashbacks. It may have saved my life; at the very least it got me back to the person I used to be.

Tips for non-specialists

  • A traumatic event can precipitate conditions other than PTSD, such as depression, phobic anxiety, and substance use disorders

  • PTSD is associated with comorbidity

  • Sensitive questioning is required to elicit symptoms of PTSD as patients may avoid volunteering their traumatic experience(s)

  • Patients with PTSD may present in primary care with physical symptoms that are difficult to explain

  • Trauma focused psychological therapy is the treatment of choice for PTSD, although drugs and other forms of psychological treatment can help

  • Patient choice and availability of psychological therapy will influence the treatment given

When to suspect PTSD

  • When patients present with mental or physical symptoms that cannot be fully explained after a traumatic event

  • When patients present with characteristic symptoms of PTSD—re-experiencing, avoidance, and hyperarousal

  • When patients disclose a history of involvement in a traumatic event

  • When patients present with mental or physical symptoms that are difficult to explain in the absence of a disclosed traumatic event

Additional educational resources

Information for healthcare professionals
  • Websites providing information on the assessment and treatment of PTSD:

    • International Society for Traumatic Stress Studies (

    • US Department of Veterans Affairs, National Centre for PTSD (

Information for patients


Cite this as: BMJ 2015;351:h6161


  • Contributors: JB, CL, and NR planned, conducted reviews, and drafted the article. SC drafted the patient’s perspective box and commented on and amended the initial draft. All authors reviewed and agreed the final draft. JB is the guarantor.

  • Competing interests: We have read and understood the BMJ policy on declaration of interests and declare the following: JB, CL, and NR have undertaken systematic reviews, meta-analyses, randomised controlled trials, and other research in the specialty of traumatic stress, some of which is referred to in the manuscript. JB, CL, and NR are members of a research team that developed a web based guided self help programme to treat PTSD. The programme is likely to be marketed in the future. Royalties will be payable to Cardiff University, with a proportion of these being shared with the research team in line with Cardiff University’s rules.

  • Provenance and peer review: Commissioned; externally peer reviewed.


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