Posttraumatic Stress Disorder

Posttraumatic stress disorder (PTSD) is an anxiety disorder characterized by the development of a constellation of cognitive, behavioral, emotional, and physiological difficulties following exposure to a traumatic event or experience. PTSD is a relatively common, recurrent, and debilitating disorder and is the focus of considerable ongoing clinical and research attention. This article reviews the signs and symptoms, epidemiology, impact, risk factors, etiology, and treatment of this important public health problem.

Posttraumatic Stress Disorder Signs and Symptoms

The symptoms of PTSD develop following exposure to a trauma. According to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), a trauma is defined as an experience in which (1) there is actual or threatened death or injury of self or others, and (2) the person’s response involves intense fear, helplessness, or horror (American Psychiatric Association, 1994). Although there is no discrete list of events that can precipitate PTSD, such experiences may include war or combat, terrorist attacks, natural or human-caused disasters, torture, being held as a prisoner of war or in a concentration camp, severe motor vehicle or other accidents, criminal/physical assault, rape, childhood physical or sexual abuse or severe neglect, diagnosis with a life-threatening illness, seeing someone killed or severely injured, seeing or handling human remains, and learning of a loved one’s severe injury, accident, or sudden, unexpected death.

Posttraumatic stress disorder involves three kinds of trauma-related symptoms: reexperiencing the trauma, avoiding reminders of the trauma or feeling emotionally numb, and hyperarousal. A person may re-experience the trauma by having repeated, distressing memories or thoughts of the experience, having nightmares, having flashbacks when he or she feels as though reliving the trauma, being emotionally upset when reminded of the trauma, and having physical reactions (e.g., racing heart, sweating) when exposed to trauma reminders. Symptoms of avoidance and numbing include avoiding thoughts, feelings, conversations, or activities that remind the person of the trauma, inability to remember important parts of the traumatic experience, loss of interest in previously enjoyable or important activities, feeling distant or detached from others, feeling emotionally numb, and having a sense of a foreshortened future (e.g., not expecting to have a normal life span). Hyperarousal symptoms include sleep difficulty, irritability, concentration problems, hypervigilance, and an exaggerated startle response. In children, PTSD symptoms may be reflected in disorganized or agitated behavior, generally frightening dreams that may not be directly linked to the trauma, and repetitive play in which aspects of the trauma are acted out.

Although many of these symptoms are common as part of the natural adjustment process following a traumatic experience, PTSD is distinguished from a normal response by the duration and impact of these symptoms. If difficulties persist for more than 1 month following the end of the traumatic experience and cause significant distress or impairment in relationships, social interactions, work or school performance, or other important areas of functioning, then a diagnosis of PTSD is likely.

A related disorder, acute stress disorder (ASD), may be diagnosed within the first month following the trauma and is viewed as a precursor to PTSD. ASD is characterized by the development of dissociative symptoms (e.g., feeling numb or detached, being in a daze, derealization, depersonalization, or amnesia), in addition to the reexperiencing, avoidance, and arousal symptoms described earlier. Again, although many of these symptoms are part of the normal trauma response, they are viewed as a disorder if they are persistent in the first month following the trauma and if they cause distress or impairment.

PTSD Epidemiology

Almost two-thirds of adult men and half of adult women have had at least one traumatic experience in their lifetime, although some studies suggest that as many as 9 in 10 adults have experienced a trauma. Of those, roughly 15% to 24% develop PTSD. The lifetime prevalence of PTSD ranges from 1% to 14%, but is twice as high in women as it is in men (10.4% vs. 5%). In addition, a significant percentage of people experience subthreshold or partial PTSD, symptoms that are distressing and impairing, but do not meet the formal diagnostic criteria for PTSD. The incidence of PTSD is higher for those who are younger and for those with fewer resources (e.g., lower socioeconomic status). The traumas most commonly associated with PTSD are combat exposure and witnessing of violence in men, and rape and sexual molestation among women. The incidence of PTSD varies widely by trauma type. For example, the lifetime prevalence of PTSD in Vietnam combat veterans is estimated to be 25% to 30%, with at least an additional 20% suffering from partial PTSD. Approximately 47% of rape victims, 21% of nonsexual assault victims, 14% of those experiencing sudden bereavement, and 9% of motor vehicle accident survivors develop chronic PTSD. Of children exposed to severe traumatic experiences, such as parental homicide or sexual assault, sexual abuse, or community/school violence, 35% to 90% may develop PTSD.

PTSD Impact

Posttraumatic stress disorder can have a devastating impact on victims and their families. PTSD is closely associated with other emotional and behavioral difficulties. Many with PTSD also have comorbid problems with depression, anxiety, guilt (e.g., at surviving a trauma when others did not, at not doing more to prevent the trauma), anger, low self-esteem, and chemical (alcohol and/or drug) abuse and dependence. By definition, those with PTSD have trouble in multiple life domains, including social and family relationships, work, school, and ability to participate in daily activities. Not surprisingly, those with PTSD may feel hopeless, often to the point of contemplating or attempting suicide. Importantly, those with PTSD may be more likely to experience a range of physical symptoms and medical problems (e.g., headaches, gastrointestinal distress, hypertension, asthma, pain, immune system problems), to engage in high-risk health behaviors, and to overutilize health care resources. Those with chronic PTSD show changes in central and autonomic nervous system functioning, including altered brain-wave activity, dysregulation of stress hormones (e.g., Cortisol, norepinephrine), and alteration of brain structure and functioning (e.g., amygdala, hippocampus).

PTSD Risk Factors

Risk factors for the development of PTSD include pre-, peri-, and postevent characteristics. Demographic (being younger, female, less educated, of lower socioeconomic status, of minority ethnicity, of lower intelligence) and historical (personal or family history of psychiatric problems, previous exposure to trauma or adverse childhood events such as abuse) have been found to predict development of PTSD in some studies. In addition, there are thought to be biological/genetic vulnerabilities to developing PTSD. Although they account for only a small amount of the variance in symptoms, greater trauma severity and exposure are associated with greater risk of PTSD. Some kinds of events—those that are unpredictable and uncontrollable, involve sexual victimization, are associated with feelings of guilt or self-blame, are felt by the victim to be extremely threatening or dangerous, or are responded to with intense fear, helplessness, or horror or with dissociation—are associated with greater risk of PTSD. Following a traumatic experience, other life stressors, loss of financial, material, or social resources, and limited or aversive social support are also associated with increased likelihood of developing PTSD.

PTSD Etiology

Many theories exist regarding the etiology of Posttraumatic stress disorder. Learning theories propose that a combination of classical and operant conditioning accounts for the development of PTSD, such that trauma-related stimuli take on an anxiety-provoking quality and that withdrawal from trauma reminders is reinforced, maintaining a cycle of fear and avoidance. Cognitive theories of PTSD focus on dysfunctional thought patterns that develop following a trauma, including overestimation of negative outcomes, misattributions regarding control and blame, and appraisal of benign situations as dangerous. Psychodynamic explanations point to inconsistencies between the individual’s view of self/the world and the meaning attributed to the traumatic event—the cycle of intrusion and avoidance is thought to reflect the struggle to reconcile these discrepancies. Biological explanations of the development of PTSD emphasize genetic/neurobiological vulnerabilities and a dysregulated physiological stress response, which result in chronic biological and neuroanatomic alterations.

Posttraumatic Stress Disorder Treatment

Although Posttraumatic stress disorder symptoms often improve over the first weeks and months following traumatization, the symptoms of approximately one-third of those with PTSD will fail to remit, and become chronic. If PTSD is still present at 3 months posttrauma, it becomes less likely that symptoms will improve without treatment. Recent evidence suggests that for some individuals diagnosed with acute stress disorder, brief cognitive-behavioral intervention initiated at 2 weeks post-trauma may prevent development of PTSD. A variety of treatment approaches have been advocated for use with PTSD. Cognitive—behavioral treatments, particularly trauma-specific exposure and cognitive therapies, have received the strongest empirical support in terms of their impact on PTSD symptoms. Exposure therapy involves systematic repetitive exposure to trauma reminders and memories, most typically via the survivor being encouraged to recount in detail the experience and his or her reactions to it, and to develop and repeat the account until emotional reactions become less intense. Cognitive therapy involves a systematic therapist-facilitated approach to identifying, challenging, and restructuring negative trauma-related beliefs (e.g., guilt). These treatments are usually delivered in 9-16 individual sessions, with additional help provided as necessary. In children with PTSD, play therapy may use games, drawings, and other techniques to help the children process their traumatic memories. Medications are often used to manage sleep difficulties, hyperarousal, and intrusive thoughts. The selective serotonin reuptake inhibitors (SSRIs) have received the most research support in terms of their impact on PTSD symptoms. In addition to cognitive-behavioral and SSRI treatments, other interventions that have received empirical support include eye movement desensitization and reprocessing and stress inoculation training. Because PTSD is associated with a variety of interpersonal difficulties and problems in functioning, group psychotherapy, marital and family therapy, parenting coaching, and social and occupational rehabilitation therapies may also be helpful.

In conclusion, Posttraumatic stress disorder is a common and potentially incapacitating disorder, which can negatively affect all life domains. Based on empirical studies, important advances are being made in prevention, detection, and treatment of this significant disorder.


  1. American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.
  2. Blanchard, E. B., & Hickling, E. J. (1997). After the crash: Assessment and treatment of motor vehicle accident survivors. Washington, DC: American Psychological Association.
  3. Brewin, C. R., Andrews, B., & Valentine, J. D. (2000). Meta-analysis of risk factors for posttraumatic stress disorder in trauma-exposed adults. Journal of Consulting and Clinical Psychology, 68, 748-766.
  4. Bryant, R. A., & Harvey, A. G. (2000). Acute stress disorder: A handbook of theory, assessment, and treatment. Washington, DC: American Psychological Association.
  5. Foa, E. B., Keane, T. M., & Friedman, M. J. (Eds.). (2000). Effective treatments for PTSD: Practice guidelines from the International Society of Traumatic Stress Studies. New York: Guilford.
  6. Foa, E. B., & Rothbaum, B. O. (1998). Treating the trauma of rape: Cognitive-behavioral therapy for PTSD. New York: Guilford.
  7. Foy, D. W. (Ed.). (1992). Treating PTSD: Cognitive-behavioral strategies. New York: Guilford.
  8. Follette, V. M., Ruzek, J. I., &Abueg, F. R. (Eds.). (1998). Cognitive-behavioral therapies for trauma. New York: Guilford.
  9. Friedman, M. J. (2000). A guide to the literature on pharmacotherapy for PTSD. PTSD Research Quarterly 77(1), 1-7.
  10. Halligan, S. L., & Yehuda, R. (2000). Risk factors for PTSD. PTSD Research Quarterly, 77(3), 1-7.
  11. Horowitz, M. (1997). Stress response syndromes (3rd ed.). New York: Aronson.
  12. Kessler, R. C., Sonnega, A., Bromet, E., Hughes, M., & Nelson, C. B. (1995). Posttraumatic stress disorder in the National Comorbidity Survey. Archives of General Psychiatry, 52, 1048-1060.
  13. Kulka, R. A., Fairbank, J. A., Jordan, B. K., Weiss, D., & Cranston, A. (1990). Trauma and the Vietnam War generation: Report of findings from the National Vietnam Veterans Readjustment Study. New York: Brunner/Mazel.
  14. Yehuda, R. (2002). Posttraumatic stress disorder. New England Journal of Medicine, 346, 108-114.
  15. Wilson, J. P., & Keane, T. M. (Eds.). (1997). Assessing psychological trauma and PTSD. New York: Guilford.

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