Posttraumatic Stress Disorder (PTSD): DSM-5

Posttraumatic stress disorder (PTSD) is a severe condition that may develop after a person is exposed to one or more traumatic events, such as sexual assault, serious injury or the threat of death. The diagnosis may be given when a group of symptoms such as disturbing recurring flashbacks, avoidance or numbing of memories of the event, and hyperarousal (high levels of anxiety) continue for more than a month after the traumatic event.

Most people who experience a traumatizing event will not develop PTSD. Women are more likely to experience more high impact trauma, and are also more likely to develop PTSD than men. Children are less likely to experience PTSD after trauma than adults, especially if they are under 10 years of age.


Posttraumatic stress disorder is an anxiety disorder; the characteristic symptoms are not present before exposure to the violently traumatic event. Typically the individual with PTSD persistently avoids all thoughts, emotions and discussion of the stressor event and may experience amnesia for it. However, the event is commonly relived by the individual through intrusive, recurrent recollections, flashbacks and nightmares. The characteristic symptoms are considered acute if lasting less than three months, and chronic if persisting three months or more, and with delayed onset if the symptoms first occur after six months or some years later. PTSD is distinct from the briefer acute stress disorder, and can cause clinical impairment in significant areas of functioning.


PTSD is believed to be caused by the experience of a wide range of traumatic events and, particularly if the trauma is extreme, can occur in persons with no predisposing conditions.

Persons considered at risk include combat military personnel, victims of natural disasters, concentration camp survivors and victims of violent crime. Individuals not infrequently experience "survivor's guilt" for remaining alive while others died. Causes of the symptoms of PTSD are the experiencing or witnessing of a stressor event involving death, serious injury or such threat to the self or others in a situation in which the individual felt intense fear, horror, or powerlessness. Persons who are employed in occupations which expose them to violence (such as soldiers) or disasters (such as emergency service workers) are also at risk.

Children or adults may develop PTSD symptoms by experiencing bullying or mobbing.

Family violence

Trauma from family violence can predispose an individual to PTSD. Approximately 25% of children exposed to family violence can experience PTSD in a study of 337 school age children. Preliminary research suggests that child abuse may interact with mutations in a stress-related gene to increase the risk of PTSD in adults, in a cross-sectional study of 900 school age children. However, being exposed to a traumatic experience doesn't automatically indicate they will develop PTSD. It has been shown that the intrusive memories, such as flashbacks, nightmares, and the memories themselves, are greater contributors to the biological and psychological dimensions of PTSD than the event itself. These intrusive memories are mainly characterized by sensory episodes, rather than thoughts. People with PTSD have intrusive re-experiences of traumatic events which lack awareness of context and time. These episodes aggravate and maintain PTSD symptoms since the individual re-experiences trauma as if it was happening in the present moment.

Multiple studies show that parental PTSD and other posttraumatic disturbances in parental psychological functioning can, despite a traumatized parent's best efforts, interfere with their response to their child as well as their child's response to trauma. For example, in two studies by Schechter, one of 67 mothers and another of 25 mothers, this was shown to be the case. Parents with violence-related PTSD may, for example, inadvertently expose their children to developmentally inappropriate violent media due to their need to manage their own emotional dysregulation. Clinical findings indicate that a failure to provide adequate treatment to children after they suffer a traumatic experience, depending on their vulnerability and the severity of the trauma, will ultimately lead to PTSD symptoms in adulthood.

Evolutionary psychology

Evolutionary psychology views different types of fears and reactions caused by fears as adaptations that may have been useful in the ancestral environment in order to avoid or cope with various threats. Mammals generally display several defensive behaviors roughly dependent on how close the threat is: avoidance, vigilant immobility, withdrawal, aggressive defense, appeasement, and finally complete frozen immobility (the last possibly to confuse a predator's attack reflex or to simulate a dead and contaminated body). PTSD may correspond to and be caused by overactivation of such fear circuits. Thus, PTSD avoidance behaviors may correspond to mammal avoidance of and withdrawal from threats. Heightened memory of past threats may increase avoidance of similar situations in the future as well as be a prerequisite for analyzing the past threat and develop better defensive behaviors if the threat should recur. PTSD hyperarousal may correspond to vigilant immobility and aggressive defense. Complex posttraumatic stress disorder (and phenomena such as the Stockholm syndrome) may in part correspond to the appeasement stage.

There may be evolutionary explanations for differences in resilience to traumatic events. Thus, PTSD is rare following a traumatic fire which may be explained by events such as forest fires long being part of the evolutionary history of mammals. On the other hand, PTSD is much more common following modern warfare, which may be explained by modern warfare being a new development and very unlike the quick inter-group raids that are argued to have characterized the paleolithic.


There is evidence that susceptibility to PTSD is hereditary. Approximately 30% of the variance in PTSD is caused from genetics alone. For twin pairs exposed to combat in Vietnam, having an identical twin with PTSD was associated with an increased risk of the co-twin having PTSD compared to twins that were non-identical twins. There is also evidence that those with a genetically smaller hippocampus are more likely to develop PTSD following a traumatic event. Research has also found that PTSD shares many genetic influences common to other psychiatric disorders. Panic and generalized anxiety disorders and PTSD share 60% of the same genetic variance. Alcohol, nicotine, and drug dependence shares greater than 40% genetic similarities.

Risk factors

Most people (more than half) will experience at least one traumatizing event in their lifetime. Men are more likely to experience a traumatic event, but women are more likely to experience the kind of high impact traumatic event that can lead to PTSD, such as interpersonal violence and sexual assault. Only a minority of people who are traumatized will develop PTSD, but they are more likely to be women. The average risk of developing PTSD after trauma is around 8% for men, while for women it is just over 20%. The risk is believed to be higher in young urban populations (24%): 13% for men and 30% for women. Rates of PTSD are higher in combat veterans than other men, with a rate estimated at up to 20% for veterans returning from Iraq and Afghanistan.

Posttraumatic stress reactions have not been studied as well in children and adolescents as adults. The rate of PTSD may be lower in children than adults, but in the absence of therapy, symptoms may continue for decades. One estimate suggests that the proportion of children and adolescents having PTSD in a non-wartorn population in a developed country may be 1% compared to 1.5% to 3% of adults, and much lower below the age of 10 years.

Predictor models have consistently found that childhood trauma, chronic adversity, and familial stressors increase risk for PTSD as well as risk for biological markers of risk for PTSD after a traumatic event in adulthood. Peri-traumatic dissociation in children is a predictive indicator of the development of PTSD later in life. This effect of childhood trauma, which is not well understood, may be a marker for both traumatic experiences and attachment problems. Proximity to, duration of, and severity of the trauma also make an impact, and interpersonal traumas cause more problems than impersonal ones.

Quasi-experimental studies have demonstrated a relationship between intrusive thoughts and intentional control responses such that suppression increases the frequency of unwanted intrusive thoughts. These results suggest that suppression of intrusive thoughts may be important in the development and maintenance of PTSD.

Military experience

Schnurr, Lunney, and Sengupta identified risk factors for the development of PTSD in Vietnam veterans. The subjects were 68 women and 414 men of whom 88 were white, 63 black, 80 Hispanic, 90 Native Hawaiian, and 93 Japanese American. Among their findings were:

Hispanic ethnicity, coming from an unstable family, being punished severely during childhood, childhood asocial behavior, and depression as pre-military factors.

War-zone exposure, peritraumatic dissociation, depression as military factors.

Recent stressful life events, post-Vietnam trauma, and depression as post-military factors.

They also identified certain protective factors, such as:

Japanese-American ethnicity, high school degree or college education, older age at entry to war, higher socioeconomic status, and a more positive paternal relationship as pre-military protective factors

Social support at homecoming and current social support as post-military factors. Other research also indicates the protective effects of social support in averting PTSD or facilitating recovery if it develops.

Glass and Jones found early intervention to be a critical preventive measure:

"PTSD symptoms can follow any serious psychological trauma, such as exposure to combat, accidents, torture, disasters, criminal assault and exposure to atrocities or to the sequelae of such extraordinary events. Prisoners of war exposed to harsh treatment are particularly prone to develop PTSD. In their acute presentation these symptoms, which include subsets of a large variety of affective, cognitive, perceptional, emotional and behavioral responses which are relatively normal responses to gross psychological trauma. If persistent, however, they develop a life of their own and may be maintained by inadvertent reinforcement. Early intervention and later avoiding positive reinforcement (which may be subtle) for such symptoms is a critical preventive measure.

Studies have shown that those prepared for the potential of a traumatic experience are more prepared to deal with the stress of a traumatic experience and therefore less likely to develop PTSD.

Drug misuse

Alcohol abuse and drug abuse commonly co-occur with PTSD. Recovery from posttraumatic stress disorder or other anxiety disorders may be hindered, or the condition worsened, by medication or substance overuse, abuse, or dependence; resolving these problems can bring about a marked improvement in an individual's mental health status and anxiety levels.

Foster care

In the Casey Family Northwest Alumni Study, conducted in conjunction with researchers from the Harvard Medical School in Oregon and Washington state, the rate of PTSD in adults who were in foster care for one year between the ages of 14–18 was found to be higher than that of combat veterans. Up to 25% of those in the study meet the diagnostic criteria for PTSD as compared to 12–13% of Iraq war veterans and 15% of Vietnam War veterans, and a rate of 4% in the general population. The recovery rate for foster home alumni was 28.2% as opposed to 47% in the general population.

Dubner and Motta (1999) found that 60% of children in foster care who had experienced sexual abuse had PTSD, and 42% of those who had been physically abused met the PTSD criteria. PTSD was also found in 18% of the children who were not physically abused. These children may have developed PTSD due to witnessing violence in the home, or as a result of real or perceived parental abandonment.


The old diagnostic criteria for PTSD, stipulated in the Diagnostic and Statistical Manual of Mental Disorders IV (Text Revision) (DSM-IV-TR), may be summarized as:

A: Exposure to a traumatic event This must have involved both (a) loss of "physical integrity", or risk of serious injury or death, to self or others, and (b) a response to the event that involved intense fear, horror, or helplessness (or in children, the response must involve disorganized or agitated behavior). (The DSM-IV-TR criterion differs substantially from the previous DSM-III-R stressor criterion, which specified the traumatic event should be of a type that would cause "significant symptoms of distress in almost anyone," and that the event was "outside the range of usual human experience.")

B: Persistent re-experiencing One or more of these must be present in the victim: flashback memories, recurring distressing dreams, subjective re-experiencing of the traumatic event(s), or intense negative psychological or physiological response to any objective or subjective reminder of the traumatic event(s).

C: Persistent avoidance and emotional numbing This involves a sufficient level of:

avoidance of stimuli associated with the trauma, such as certain thoughts or feelings, or talking about the event(s);

avoidance of behaviors, places, or people that might lead to distressing memories as well as the disturbing memories, dreams, flashbacks, and intense psychological or physiological distress;

inability to recall major parts of the trauma(s), or decreased involvement in significant life activities;

decreased capacity (down to complete inability) to feel certain feelings;

an expectation that one's future will be somehow constrained in ways not normal to other people.

D: Persistent symptoms of increased arousal not present before These are all physiological response issues, such as difficulty falling or staying asleep, or problems with anger, concentration, or hypervigilance. Additional symptoms include irritability, angry outbursts, increased startle response, and concentration or sleep problems.

E: Duration of symptoms for more than 1 month If all other criteria are present, but 30 days have not elapsed, the individual is diagnosed with Acute stress disorder.

F: Significant impairment The symptoms reported must lead to "clinically significant distress or impairment" of major domains of life activity, such as social relations, occupational activities, or other "important areas of functioning".


Since the introduction of old DSM-IV, the number of possible events which might be used to diagnose PTSD has increased; one study suggests that the increase is around 50%. Various scales exist to measure the severity and frequency of PTSD symptoms. Standardized screening tools such as Trauma Screening Questionnaire and PTSD Symptom Scale can be used to detect possible symptoms of posttraumatic stress disorder and suggest the need for a formal diagnostic assessment.


In DSM-5, published in May, 2013, PTSD is classified as a trauma- and stress-related disorder.

Criterion A: (applicable to adults, adolescents and children over 6. There is a separate Posttraumatic stress disorder for children 6 years and younger.) Exposure to real or threatened death, injury, or sexual violence.

Several items in Criterion B (intrusion symptoms) are rewritten to add or augment certain distinctions now considered important.

Special consideration is given to developmentally appropriate criteria for use with children and adolescents. This is especially evident in the restated Criterion B—intrusion symptoms. Development of age-specific criteria for diagnosis of PTSD is ongoing at this time.

Criterion C (avoidance and numbing) has been split into "C" and "D":

Criterion C (new version) now focuses solely on avoidance of behaviors or physical or temporal reminders of the traumatic experience(s). What were formerly two symptoms are now three, due to slight changes in descriptions.

New Criterion D focuses on negative alterations in cognition and mood associated with the traumatic event(s) and contains two new symptoms, one expanded symptom, and four largely unchanged symptoms specified in the previous criteria.

Criterion E (formerly "D"), which focuses on increased arousal and reactivity, contains one modestly revised, one entirely new, and four unchanged symptoms.

Criterion F (formerly "E") still requires duration of symptoms to have been at least one month.

Criterion G (formerly "F") stipulates symptom impact ("disturbance") in the same way as before.

Criterion H stipulated the disturbance is not due to the effects of a substance or another medical condition.

Specify whether:

With dissociative symptoms: (not due to effects of a substance or another medical condition)

In addition, meets the criteria of "Depersonalization"

In addition, meets the criteria of "Derealization"

Specify if:

With delayed expression Full criteria not met until more than 6 months after the event

Research-based groups

Emerging factor analytic research suggests that PTSD symptoms group empirically into four clusters, not the three currently described in the Diagnostic and Statistical Manual of Mental Disorders[dated info]. One model supported by this research divides the traditional avoidance symptoms into a cluster of numbing symptoms (such as loss of interest and feeling emotionally numb) and a cluster of behavioral avoidance symptoms (such as avoiding reminders of the trauma). An alternative model adds a fourth cluster of dysphoric symptoms. These include symptoms of emotional numbing, as well as anger, sleep disturbance, and difficulty concentrating (traditionally grouped under the hyperarousal cluster). A literature review and meta-analysis did not find strong support across the literature for one of these models over the other.

International Classification of Diseases

The diagnostic criteria for PTSD, stipulated in the International Statistical Classification of Diseases and Related Health Problems 10 (ICD-10), may be summarized as:

Exposure to a stressful event or situation (either short or long lasting) of exceptionally threatening or catastrophic nature, which is likely to cause pervasive distress in almost anyone.

Persistent remembering or "reliving" the stressor by intrusive flash backs, vivid memories, recurring dreams, or by experiencing distress when exposed to circumstances resembling or associated with the stressor.

Actual or preferred avoidance of circumstances resembling or associated with the stressor (not present before exposure to the stressor).

Either (1) or (2):

Inability to recall, either partially or completely, some important aspects of the period of exposure to the stressor

Persistent symptoms of increased psychological sensitivity and arousal (not present before exposure to the stressor) shown by any two of the following:

difficulty in falling or staying asleep;

irritability or outbursts of anger;

difficulty in concentrating;


exaggerated startle response

The International Statistical Classification of Diseases and Related Health Problems 10 diagnostic guidelines state:

1.This disorder should not generally be diagnosed unless there is evidence that it arose within 6 months of a traumatic event of exceptional severity.

2. A "probable" diagnosis might still be possible if the delay between the event and the onset was longer than 6 months, provided that the clinical manifestations are typical and no alternative identification of the disorder (e.g. as an anxiety or obsessive-compulsive disorder or depressive episode) is plausible.

3. In addition to evidence of trauma, there must be a repetitive, intrusive recollection or re-enactment of the event in memories, daytime imagery, or dreams.

4. Conspicuous emotional detachment, numbing of feeling, and avoidance of stimuli that might arouse recollection of the trauma are often present but are not essential for the diagnosis.

5. The autonomic disturbances, mood disorder, and behavioural abnormalities all contribute to the diagnosis but are not of prime importance.

Differential diagnosis

A diagnosis of PTSD requires exposure to an extreme stressor such as one that is life-threatening. Any stressor can result in a diagnosis of adjustment disorder and it is an appropriate diagnosis for a stressor and a symptom pattern that does not meet the criteria for PTSD, for example a stressor like a partner being fired, or a spouse leaving. If any of the symptom pattern is present before the stressor, another diagnosis is required, such as brief psychotic disorder or major depressive disorder. Other differential diagnoses are schizophrenia or other disorders with psychotic features such as Psychotic disorders due to a general medical condition. Drug-induced psychotic disorders can be considered if substance abuse is involved.

The symptom pattern for acute stress disorder must occur and be resolved within four weeks of the trauma. If it lasts longer, and the symptom pattern fits that characteristic of PTSD, the diagnosis may be changed.

Obsessive compulsive disorder may be diagnosed for intrusive thoughts that are recurring but not related to a specific traumatic event.

Malingering should be considered if a financial and/or legal advantage is a possibility.