Diagnostic Features
The essential feature of Posttraumatic Stress Disorder is the development of characteristic symptoms following exposure to an extreme traumatic stressor involving direct personal experience of an event that involves actual or threatened death or serious injury, or other threat to one’s physical integrity; or witnessing an event that involves death, injury, or a threat to the physical integrity of another person; or learning about unexpected or violent death, serious harm, or threat of death or injury experienced by a family member or other close associate (Criterion A1). The person’s response to the event must involve intense fear, helplessness, or horror (or in children, the response must involve disorganized or agitated behavior) (Criterion A2). The characteristic symptoms resulting from the exposure to the extreme trauma include persistent reexperiencing of the traumatic event (Criterion B), persistent avoidance of stimuli associated with the trauma and numbing of gener

For children, sexually traumatic events may include developmentally inappropriate sexual experiences without threatened or actual violence or injury. Witnessed events include, but are not limited to, observing the serious injury or unnatural death of another person due to violent assault, accident, war, or disaster or unexpectedly witnessing a dead body or body parts. Events experienced by others that are learned about include, but are not limited to, violent personal assault, serious accident, or serious injury experienced by a family member or a close friend; learning about the sudden, unexpected death of a family member or a close friend; or learning that one’s child has a life-threatening disease. The disorder may be especially severe or long lasting when the stressor is of human design (e.g., torture, rape). The likelihood of developing this disorder may increase as the intensity of and physical proximity to the stressor increase.

The traumatic event can be reexperienced in various ways. Commonly the person has recurrent and intrusive recollections of the event (Criterion B1) or recurrent distressing dreams during which the event can be replayed or otherwise represented (Criterion B2). In rare instances, the person experiences dissociative states that last from a few seconds to several hours, or even days, during which components of the event are relived and the person behaves as though experiencing the event at that moment (Criterion B3). These episodes, often referred to as “flashbacks,” are typically brief but can be associated with prolonged distress and heightened arousal. Intense psychological distress (Criterion B4) or physiological reactivity (Criterion B5) often occurs when the person is exposed to triggering events that resemble or symbolize an aspect of the traumatic event (e.g., anniversaries of the traumatic event; cold, snowy weather or uniformed guards for survivors of death camps in cold climates; hot, humid weather for combat veterans of the South Pacific; entering any elevator for a woman who was raped in an elevator).

Stimuli associated with the trauma are persistently avoided. The person commonly makes deliberate efforts to avoid thoughts, feelings, or conversations about the traumatic event (Criterion C1) and to avoid activities, situations, or people who arouse recollections of it (Criterion C2). This avoidance of reminders may include amnesia for an important aspect of the traumatic event (Criterion C3). Diminished responsiveness to the external world, referred to as “psychic numbing” or “emotional anesthesia,” usually begins soon after the traumatic event. The individual may complain of having markedly diminished interest or participation in previously enjoyed activities (Criterion C4), of feeling detached or estranged from other people (Criterion C5), or of having markedly reduced ability to feel emotions (especially those associated with intimacy, tenderness, and sexuality) (Criterion C6). The individual may have a sense of a foreshortened future (e.g., not expecting to have a career, marriage, children, or a normal life span) (Criterion C7).

The individual has persistent symptoms of anxiety or increased arousal that were not present before the trauma. These symptoms may include difficulty falling or staying asleep that may be due to recurrent nightmares during which the traumatic event is relived (Criterion D1), hypervigilance (Criterion D4), and exaggerated startle response (Criterion D5). Some individuals report irritability or outbursts of anger (Criterion D2) or difficulty concentrating or completing tasks (Criterion D3).

Specifiers
The following specifiers may be used to specify onset and duration of the symptoms of Posttraumatic Stress Disorder:

Acute. This specifier should be used when the duration of symptoms is less than 3 months.

Chronic. This specifier should be used when the symptoms last 3 months or longer.

With Delayed Onset. This specifier indicates that at least 6 months have passed between the traumatic event and the onset of the symptoms.

Associated Features and Disorders
Associated descriptive features and mental disorders. Individuals with Posttraumatic Stress Disorder may describe painful guilt feelings about surviving when others did not survive or about the things they had to do to survive. Avoidance patterns may interfere with interpersonal relationships and lead to marital conflict, divorce, or loss of job. Auditory hallucinations and paranoid ideation can be present in some severe and chronic cases. The following associated constellation of symptoms may occur and are more commonly seen in association with an interpersonal stressor (e.g., childhood sexual or physical abuse, domestic battering): impaired affect modulation; self-destructive and impulsive behavior; dissociative symptoms; somatic complaints; feelings of ineffectiveness, shame, despair, or hopelessness; feeling permanently damaged; a loss of previously sustained beliefs; hostility; social withdrawal; feeling constantly threatened; impaired relationships with others; or a change from the individual’s previous personality characteristics.

Posttraumatic Stress Disorder is associated with increased rates of Major Depressive Disorder, Substance-Related Disorders, Panic Disorder, Agoraphobia, Obsessive-Compulsive Disorder, Generalized Anxiety Disorder, Social Phobia, Specific Phobia, and Bipolar Disorder. These disorders can either precede, follow, or emerge concurrently with the onset of Posttraumatic Stress Disorder.

Associated laboratory findings. Increased arousal may be measured through studies of autonomic functioning (e.g., heart rate, electromyography, sweat gland activity).

Associated physical examination findings and general medical conditions. Physical injuries may occur as a direct consequence of the trauma. In addition, chronic Posttraumatic Stress Disorder may be associated with increased rates of somatic complaints and, possibly, general medical conditions.

Specific Culture and Age Features
Individuals who have recently emigrated from areas of considerable social unrest and civil conflict may have elevated rates of Posttraumatic Stress Disorder. Such individuals may be especially reluctant to divulge experiences of torture and trauma due to their vulnerable political immigrant status. Specific assessments of traumatic experiences and concomitant symptoms are needed for such individuals.

In younger children, distressing dreams of the event may, within several weeks, change into generalized nightmares of monsters, of rescuing others, or of threats to self or others. Young children usually do not have the sense that they are reliving the past; rather, the reliving of the trauma may occur through repetitive play (e.g., a child who was involved in a serious automobile accident repeatedly reenacts car crashes with toy cars). Because it may be difficult for children to report diminished interest in significant activities and constriction of affect, these symptoms should be carefully evaluated with reports from parents, teachers, and other observers. In children, the sense of a foreshortened future may be evidenced by the belief that life will be too short to include becoming an adult. There may also be “omen formation”—that is, belief in an ability to foresee future untoward events. Children may also exhibit various physical symptoms, such as stomachaches and headaches.

Prevalence
Community-based studies reveal a lifetime prevalence for Posttraumatic Stress Disorder of approximately 8% of the adult population in the United States. Information is not currently available with regard to the general population prevalence in other countries. Studies of at-risk individuals (i.e., groups exposed to specific traumatic incidents) yield variable findings, with the highest rates (ranging between one-third and more than half of those exposed) found among survivors of rape, military combat and captivity, and ethnically or politically motivated internment and genocide.

Course
Posttraumatic Stress Disorder can occur at any age, including childhood. Symptoms usually begin within the first 3 months after the trauma, although there may be a delay of months, or even years, before symptoms appear. Frequently, a person’s reaction to a trauma initially meets criteria for Acute Stress Disorder in the immediate aftermath of the trauma. The symptoms of the disorder and the relative predominance of reexperiencing, avoidance, and hyperarousal symptoms may vary over time. Duration of the symptoms varies, with complete recovery occurring within 3 months in approximately half of cases, with many others having persisting symptoms for longer than 12 months after the trauma. In some cases, the course is characterized by a waxing and waning of symptoms. Symptom reactivation may occur in response to reminders of the original trauma, life stressors, or new traumatic events.

The severity, duration, and proximity of an individual’s exposure to the traumatic event are the most important factors affecting the likelihood of developing this disorder. There is some evidence that social supports, family history, childhood experiences, personality variables, and preexisting mental disorders may influence the development of Posttraumatic Stress Disorder. This disorder can develop in individuals without any predisposing conditions, particularly if the stressor is especially extreme.

Familial Pattern
There is evidence of a heritable component to the transmission of Posttraumatic Stress Disorder. Furthermore, a history of depression in first-degree relatives has been related to an increased vulnerability to developing Postraumatic Stress Disorder.

Differential Diagnosis
In Posttraumatic Stress Disorder, the stressor must be of an extreme (i.e., life-threatening) nature. In contrast, in Adjustment Disorder, the stressor can be of any severity. The diagnosis of Adjustment Disorder is appropriate both for situations in which the response to an extreme stressor does not meet the criteria for Posttraumatic Stress Disorder (or another specific mental disorder) and for situations in which the symptom pattern of Posttraumatic Stress Disorder occurs in response to a stressor that is not extreme (e.g., spouse leaving, being fired).

Not all psychopathology that occurs in individuals exposed to an extreme stressor should necessarily be attributed to Posttraumatic Stress Disorder. Symptoms of avoidance, numbing, and increased arousal that are present before exposure to the stressor do not meet criteria for the diagnosis of Posttraumatic Stress Disorder and require consideration of other diagnoses (e.g., a Mood Disorder or another Anxiety Disorder). Moreover, if the symptom response pattern to the extreme stressor meets criteria for another mental disorder (e.g., Brief Psychotic Disorder, Conversion Disorder, Major Depressive Disorder), these diagnoses should be given instead of, or in addition to, Posttraumatic Stress Disorder.

Acute Stress Disorder is distinguished from Posttraumatic Stress Disorder because the symptom pattern in Acute Stress Disorder must occur within 4 weeks of the traumatic event and resolve within that 4-week period. If the symptoms persist for more than 1 month and meet criteria for Posttraumatic Stress Disorder, the diagnosis is changed from Acute Stress Disorder to Posttraumatic Stress Disorder.

In Obsessive-Compulsive Disorder, there are recurrent intrusive thoughts, but these are experienced as inappropriate and are not related to an experienced traumatic event. Flashbacks in Posttraumatic Stress Disorder must be distinguished from illusions, hallucinations, and other perceptual disturbances that may occur in Schizophrenia, other Psychotic Disorders, Mood Disorder With Psychotic Features, a delirium, Substance-Induced Disorders, and Psychotic Disorders Due to a General Medical Condition.

Malingering should be ruled out in those situations in which financial remuneration, benefit eligibility, and forensic determinations play a role.

Diagnostic criteria for Posttraumatic Stress Disorder

A. The person has been exposed to a traumatic event in which both of the following were present:
(1) the person experienced, witnessed, or was confronted with an event or events that involved actual or threatened death or serious injury, or a threat to the physical integrity of self or others
(2) the person’s response involved intense fear, helplessness, or horror. Note: In children, this may be expressed instead by disorganized or agitated behavior

B. The traumatic event is persistently reexperienced in one (or more) of the following ways:
(1) recurrent and intrusive distressing recollections of the event, including images, thoughts, or perceptions. Note: In young children, repetitive play may occur in which themes or aspects of the trauma are expressed.
(2) recurrent distressing dreams of the event. Note: In children, there may be frightening dreams without recognizable content.
(3) acting or feeling as if the traumatic event were recurring (includes a sense of reliving the experience, illusions, hallucinations, and dissociative flashback episodes, including those that occur on awakening or when intoxicated). Note: In young children, trauma-specific reenactment may occur.
(4) intense psychological distress at exposure to internal or external cues that symbolize or resemble an aspect of the traumatic event
(5) physiological reactivity on exposure to internal or external cues that symbolize or resemble an aspect of the traumatic event

C. Persistent avoidance of stimuli associated with the trauma and numbing of general responsiveness (not present before the trauma), as indicated by three (or more) of the following:
(1) efforts to avoid thoughts, feelings, or conversations associated with the trauma
(2) efforts to avoid activities, places, or people that arouse recollections of the trauma
(3) inability to recall an important aspect of the trauma
(4) markedly diminished interest or participation in significant activities
(5) feeling of detachment or estrangement from others
(6) restricted range of affect (e.g., unable to have loving feelings)
(7) sense of a foreshortened future (e.g., does not expect to have a career, marriage, children, or a normal life span)

D. Persistent symptoms of increased arousal (not present before the trauma), as indicated by two (or more) of the following:
(1) difficulty falling or staying asleep
(2) irritability or outbursts of anger
(3) difficulty concentrating
(4) hypervigilance
(5) exaggerated startle response

E. Duration of the disturbance (symptoms in Criteria B, C, and D) is more than 1 month.
F. The disturbance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.

Specify if:

Acute: if duration of symptoms is less than 3 months

Chronic: if duration of symptoms is 3 months or more

Specify if:

With Delayed Onset: if onset of symptoms is at least 6 months after the stressor