Post-Traumatic Stress Disorder

Learning Objectives

  • Describe the diagnosis and symptoms associated with post-traumatic stress disorder
  • Describe risk factors and possible causes of post-traumatic stress disorder

Extremely stressful or traumatic events, such as combat, natural disasters, and terrorist attacks, place the people who experience them at an increased risk for developing psychological disorders such as post-traumatic stress disorder (PTSD). Throughout much of the 20th century, this disorder was called shell shock and combat neurosis because its symptoms were observed in soldiers who had engaged in wartime combat. By the late 1970s, information had become clear that people who had experienced sexual traumas (e.g., rape, domestic battery, and incest) often experienced the same set of symptoms as did soldiers (Herman, 1997). The term post-traumatic stress disorder was developed given that these symptoms could happen to anyone who experienced psychological trauma.

Word cloud about ptsd.

Figure 1. PTSD is caused by extremely stressful or threatening situations that can happen to anyone.

A Broader Definition of Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) was listed among the anxiety disorders in previous DSM editions. In DSM-5, it is now listed among a group called trauma-and-stressor-related disorders. For a person to be diagnosed with post-traumatic stress disorder (PTSD), they be must exposed to, witness, or experience the details of a traumatic experience (e.g., a first responder), one that involves “actual or threatened death, serious injury, or sexual violence” (APA, 2013, p. 271). These experiences can include such events as combat, threatened or actual physical attack, sexual assault, natural disasters, terrorist attacks, and automobile accidents. This criterion makes PTSD the only disorder listed in the DSM in which a cause (extreme trauma) is explicitly specified.

Symptoms of PTSD include intrusive and distressing memories of the event, flashbacks (states that can last from a few seconds to several days, during which the individual relives the event and behaves as if the event were occurring at that moment [APA, 2013]), avoidance of stimuli connected to the event, persistently negative emotional states (e.g., fear, anger, guilt, and shame), feelings of detachment from others, irritability, proneness toward outbursts, and an exaggerated startle response (jumpiness). For PTSD to be diagnosed, these symptoms must occur for at least one month.

Photo of soldier who appears sad

Figure 2. PTSD, originally called shell shock, was diagnosed in wartime soldiers but eventually noted that it can happen to anyone exposed to an extremely stressful or threatening situation(s).

Roughly 7% of adults in the United States, including 9.7% of women and 3.6% of men, experience PTSD in their lifetime (National Comorbidity Survey, 2007), with higher rates among people exposed to mass trauma and people whose jobs involve duty-related trauma exposure (e.g., police officers, firefighters, and emergency medical personnel) (APA, 2013). Nearly 21% of residents of areas affected by Hurricane Katrina suffered from PTSD one year following the hurricane (Kessler et al., 2008), and 12.6% of Manhattan residents were observed as having PTSD two to three years after the 9/11 terrorist attacks (DiGrande et al., 2008).

Diagnosing PTSD

To diagnose PTSD, an individual must experience at least some symptoms among four different categories for at least a month after a traumatic event: intrusion symptoms (recurrent/distressing memories), avoidance of stimuli related to the event, negative changes in mood, and changes in arousal/reactivity.

1. Presence of one (or more) of the following intrusion symptoms associated with the traumatic event(s) occurred:

  • recurrent, involuntary, and intrusive distressing memories of the traumatic event(s); in children older than six, there may be frightening dreams without recognizable content.
  • recurrent distressing dreams in which the content and/or effect of the dream are related to the traumatic event(s)
  • dissociative reactions (e.g., flashbacks) in which the individual feels or acts as if the trauma event(s) were recurring (such reactions may occur on a continuum, with the most extreme expression being a complete loss of awareness of present surroundings); in children, trauma-specific reenactment may occur in play
  • intense or prolonged psychological distress at exposure to internal or external cues symbolizing or resembling an aspect of the traumatic event(s)
  • marked physiological reactions to internal or external cues that symbolize or resemble an aspect of the traumatic event(s)

2. Persistent avoidance of stimuli associated with the traumatic event(s), beginning after the traumatic event(s) occurred, as evidenced by one or both of the following:

  • avoidance of or efforts to avoid distressing memories, thoughts, or feelings about or closely associated with the traumatic event(s)
  • avoidance of or efforts to avoid external reminders (people, places, conversations, activities, objects, or situations) that arouse distressing memories, thoughts, or feelings about or closely associated with the traumatic event(s)

3. Negative alterations in cognitions and mood associated with the traumatic events(s), beginning or worsening after the traumatic event(s), as evidenced by two (or more) of the following:

  • inability to remember an important aspect of the traumatic events(s) (typically due to dissociative amnesia and not to other factors such as head injury, alcohol, or drugs)
  • persistent and exaggerated negative beliefs or expectations about oneself, others, or the world (e.g., “I am bad,” “no one can be trusted,” “the world is completely dangerous,” “my whole nervousness system is permanently ruined”)
  • persistent, distorted cognitions about the cause or consequences of the traumatic event(s) that lead individuals to blame themselves or others
  • persistent negative emotional state (e.g., fear, horror, anger, guilt, or shame)
  • markedly diminished interest or participation in significant activities
  • feelings of detachment or estrangement from others
  • persistent inability to experience positive emotions (e.g., inability to experience happiness, satisfaction, or loving feelings)

4. Marked alterations in arousal and reactivity associated with the traumatic event(s), beginning or worsening after the traumatic event(s) occurred, as evidenced by two (or more) of the following:

  • irritable behavior and angry outbursts (with little or no provocation) typically expressed as verbal or physical aggression toward people or objects
  • reckless or self-destructive behavior
  • hypervigilance
  • exaggerated startle response
  • problems with concentration
  • sleep disturbances

Try It

Risk Factors for PTSD

Bar graph showing causes of PTSD. Physical assault is 70%, other sexual trauma is 64%, sexual assault is 57%, sudden death of a loved one 43%, transportation 40%, illness or injury 34%, weapon assault 32%, sever suffering 21%, accident 19%, natural disaster 14%, and military/war at 6%.

Figure 3. Causes of PTSD by type of trauma infographic. Data from Australian adults, 2011.

Of course, not everyone who experiences a traumatic event will go on to develop PTSD; several factors strongly predict the development of PTSD: trauma experience, greater trauma severity, lack of immediate social support, and more subsequent life stress (Brewin, Andrews, & Valentine, 2000). Traumatic events that involve harm by others (e.g., combat, rape, and sexual molestation) carry greater risk than do other traumas (e.g., natural disasters) (Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995). Women are more likely to have been traumatized because of sexual trauma, childhood neglect, and childhood physical abuse. Men are more likely to have been traumatized by natural disaster, life-threatening accidents, and physical violence, either witnessed or directed at them. Adolescent boys are more likely to experience accident, physical assault, and witness death/injury; adolescent girls are more likely to experience rape/sexual assault, intimate partner violence, or unexpected death or injury of a loved one. Assaultive violence and witnessing trauma to others is more prevalent among non-Whites when compared to Whites. African American males are more likely to be exposed to and be victims of violence than males of other races (Kilpatrick, Badour, & Resnick, 2017). A 2012 study found that 27% of corrections officers reported experiencing symptoms of PTSD in the past 30 days. Rates were higher for males (31%) than females (22%) (Spinaris, Denhof, & Kellaway, 2012). A study conducted by Jaegers et al (2019) found that 53.4% of jail correctional officers screened positively for PTSD. PTSD is more prevalent in prison populations than in the general public, with prevalence estimates of 6% in male prisoners and 21% in female prisoners (Facer-Irwin et al, 2019).

Factors that increase the risk of PTSD include female gender (based on biological differences), low SES, low intelligence, personal history of mental disorders, history of childhood adversity (abuse or other trauma during childhood), and family history of mental disorders (Brewin et al., 2000). Personality characteristics such as neuroticism and somatization (the tendency to experience physical symptoms when one encounters stress) have been shown to elevate the risk of PTSD (Bramsen, Dirkzwager, & van der Ploeg, 2000). People who experience childhood adversity and/or traumatic experiences during adulthood are at significantly higher risk of developing PTSD if they possess one or two short versions of a gene that regulates the neurotransmitter serotonin (Xie et al., 2009). This suggests a possible diathesis-stress interpretation of PTSD: its development is influenced by the interaction of psychosocial and biological factors.

Support for Sufferers of PTSD

Research has shown that social support following a traumatic event can reduce the likelihood of PTSD (Ozer, Best, Lipsey, & Weiss, 2003). Social support is often defined as the comfort, advice, and assistance received from relatives, friends, and neighbors. Social support can help individuals cope during difficult times by allowing them to discuss feelings and experiences and providing a sense of being loved and appreciated. A 14-year study of 1,377 American Legionnaires who had served in the Vietnam War found that those who perceived less social support when they came home were more likely to develop PTSD than were those who perceived greater support. In addition, individuals who became involved in the community were less likely to develop PTSD, and they were more likely to experience a remission of PTSD than were those who were less involved (Koenen, Stellman, Stellman, & Sommer, 2003).

A photograph shows a person looking at the Vietnam Traveling Memorial Wall.

Figure 4. PTSD was first recognized in soldiers who had engaged in combat. Research has shown that strong social support decreases the risk of PTSD. This person stands at the Vietnam Traveling Memorial Wall. (credit: Kevin Stanchfield)

Behaviorism and Development of PTSD

PTSD learning models suggest that some symptoms are developed and maintained through classical conditioning. The traumatic event may act as an unconditioned stimulus that elicits an unconditioned response characterized by extreme fear and anxiety. Cognitive, emotional, physiological, and environmental cues accompanying or related to the event are conditioned stimuli. These traumatic reminders evoke conditioned responses (extreme fear and anxiety) similar to those caused by the event itself (Nader, 2001). A person who was in the vicinity of the Twin Towers during the 9/11 terrorist attacks and who developed PTSD may display excessive hypervigilance and distress when planes fly overhead; this behavior constitutes a conditioned response to the traumatic reminder (conditioned stimulus of the sight and sound of an airplane). Differences in how conditionable individuals are, help to explain differences in the development and maintenance of PTSD symptoms (Pittman, 1988). Conditioning studies demonstrate facilitated acquisition of conditioned responses and delayed extinction of conditioned responses in people with PTSD (Orr et al., 2000).

Cognition and PTSD

Cognitive factors are important in the development and maintenance of PTSD. One model suggests that two key processes are crucial: disturbances in memory for the event, and negative appraisals of the trauma and its aftermath (Ehlers & Clark, 2000). According to this theory, some people who experience traumas do not form coherent memories of the trauma; memories of the traumatic event are poorly encoded and, thus, are fragmented, disorganized, and lacking in detail. Therefore, these individuals are unable to remember the event in a way that gives it meaning and context. A rape victim who cannot coherently remember the event may remember only bits and pieces (e.g., the attacker repeatedly telling her she is stupid); because she was unable to develop a fully integrated memory, the fragmentary memory tends to stand out. Although unable to retrieve a complete memory of the event, she may be haunted by intrusive fragments involuntarily triggered by stimuli associated with the event (e.g., memories of the attacker’s comments when encountering a person who resembles the attacker). This interpretation fits previously discussed material concerning PTSD and conditioning. The model also proposes that negative appraisals of the event (“I deserved to be raped because I’m stupid”) may lead to dysfunctional behavioral strategies (e.g., avoiding social activities where men are likely to be present) that maintain PTSD symptoms by preventing both a change in the nature of the memory and a change in the problematic appraisals.

Key Takeaways: PTSD

Watch It

Watch this video to review the symptoms of PTSD and consider some possible treatment options.

You can view the transcript for “Posttraumatic stress disorder (PTSD) – causes, symptoms, treatment & pathology” here (opens in new window).

Try It

Glossary

flashback: psychological state lasting from a few seconds to several days, during which one relives a traumatic event and behaves as though the event were occurring at that moment

post-traumatic stress disorder (PTSD): experiencing a profoundly traumatic event leads to a constellation of symptoms that include intrusive and distressing memories of the event, avoidance of stimuli connected to the event, negative emotional states, feelings of detachment from others, irritability, proneness toward outbursts, hypervigilance, and a tendency to startle easily; these symptoms must occur for at least one month