In This Article Expand or collapse the "in this article" section Posttraumatic Stress Disorder (PTSD)

  • Introduction
  • Introductory Works
  • What Is a Traumatic Event?
  • Symptoms of PTSD
  • Current Conceptualizations
  • Epidemiology
  • Course
  • Theoretical Models
  • Cross-Cultural Observations

Psychology Posttraumatic Stress Disorder (PTSD)
Chris R. Brewin
  • LAST REVIEWED: 26 February 2020
  • LAST MODIFIED: 26 February 2020
  • DOI: 10.1093/obo/9780199828340-0094


Severe reactions to experiences such as combat and railway accidents have been described since the mid-19th century by numerous physicians, including Sigmund Freud and Pierre Janet. These descriptions include two types of characteristic symptoms: dissociative symptoms, in which there is a general disturbance in normal mental functions, such as memory, consciousness, time estimation, sense of reality, and identity, and reexperiencing symptoms, in which the traumatic event is vividly relived as though it were happening all over again in the present. Despite this early recognition, posttraumatic stress disorder (PTSD) was formally defined only in the third edition of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders: DSM-III (Washington, DC: American Psychiatric Association, 1980). Prior to this, exposure to stress was assumed to produce only short-term problems in adjustment. In the DSM-III, PTSD required exposure to “a recognizable stressor that would evoke significant symptoms of distress in almost everyone” (p. 238) and was “outside the range of normal human experience” (p. 236). In addition four symptoms had to be present reflecting reexperiencing of the traumatic event, numbing and detachment, and a more pervasive change in arousal or emotions. The introduction of the disorder in the DSM-III was strongly influenced by studies of combat veterans and women in violent relationships, which suggested the existence of more long-lasting psychiatric conditions, variously termed “combat neurosis,” “rape trauma syndrome,” or “battered women syndrome.” The PTSD diagnosis was designed to subsume these syndromes and capture what was considered to be an essentially normal response to any overwhelming trauma. This made it unlike other psychiatric disorders, which all implied some vulnerability on the part of the person who succumbed to it. The definition was refined in the Diagnostic and Statistical Manual of Mental Disorders: DSM-III-R published in 1987, which introduced more symptoms and required at least one reexperiencing symptom (e.g., intrusive memories or nightmares), three avoidance or numbing symptoms (e.g., avoidance of reminders of the traumatic event or loss of interest in activities), and two hyperarousal symptoms (e.g., exaggerated startle or irritability). Diagnostic and Statistical Manual of Mental Disorders: DSM-IV, introduced in 1994, retained a similar structure. The 2013 Diagnostic and Statistical Manual of Mental Disorders: DSM-5 increased the number of symptoms from seventeen to twenty and reorganized them into four symptom clusters, reexperiencing, avoidance, negative alterations in cognition and mood, and alterations in arousal and reactivity. In 1992 PTSD also appeared in another major international classification system, the tenth edition of the World Health Organization’s International Classification of Diseases (ICD-10) (Geneva, Switzerland: World Health Organization, 1992–1994). This formulation placed more emphasis on “episodes of repeated reliving of the trauma in intrusive memories (‘flashbacks’) or dreams” and also identified avoidance, numbing, and hyperarousal as central features. International Classification of Diseases (ICD-11) (Geneva, Switzerland: World Health Organization, 2019) greatly simplified the PTSD diagnosis, requiring one out of two reexperiencing symptoms, one out of two avoidance symptoms, and one out of two sense of threat symptoms, along with impairment in functioning.

Introductory Works

The history of the recognition of posttraumatic reactions starting in the 19th century is described in a number of publications (Weisaeth 2014, Wilson 1994). One of the most influential 20th-century theorists has been the psychiatrist Mardi J. Horowitz, whose work Horowitz 2011 on general reactions to stressors such as bereavement played a major role in the original formulation of PTSD in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders: DSM-III (Washington, DC: American Psychiatric Association, 1980). As of the early 21st century, PTSD and its close relative, acute stress disorder, remain the only psychiatric disorders to specify a causal agent, and PTSD continues to be a controversial diagnosis. The main criticisms are that the disorder was introduced for political rather than scientific reasons, that it inappropriately medicalizes normal human reactions, that it gives too much weight to the stressful event and not enough to the person, that it is not distinct from other recognized disorders, and that its symptom structure is too complex (Brewin 2003; Rosen and Lilienfeld 2008; Spitzer, et al. 2007; Young 1995).

  • Brewin, Chris R. 2003. Posttraumatic stress disorder: Malady or myth? New Haven, CT: Yale Univ. Press.

    Text written for a general audience that reviews the historical and scientific controversies over PTSD and related issues, such as recovered memories of trauma. Presents an evidence-based update of current knowledge.

  • Horowitz, Mardi J. 2011. Stress response syndromes: PTSD, grief, adjustment, and dissociative disorders. 5th ed. Plymouth, UK: Jason Aronson.

    A landmark text putting forward an information-processing model of response to stress involving the interplay of involuntary thoughts and images and the attempts made to avoid them. The first edition, published in 1976, had a major influence on shaping the phenomenology of PTSD in the DSM-III.

  • Rosen, Gerald M., and Scott O. Lilienfeld. 2008. Posttraumatic stress disorder: An empirical evaluation of core assumptions. Clinical Psychology Review 28.5: 837–868.

    DOI: 10.1016/j.cpr.2007.12.002

    The authors dispute the premise that a distinct class of traumatic events is linked to a distinct clinical syndrome, the core assumption that ostensibly distinguishes the PTSD diagnosis from virtually all other psychiatric disorders. They conclude that virtually all core assumptions and hypothesized mechanisms of PTSD lack compelling empirical support. Available online for purchase or by subscription.

  • Spitzer, Robert L., Michael B. First, and Jerome C. Wakefield. 2007. Saving PTSD from itself in DSM-V. Journal of Anxiety Disorders 21.2: 233–241.

    DOI: 10.1016/j.janxdis.2006.09.006

    The authors review evidence that fails to support some of the key assumptions behind the PTSD diagnosis and propose more stringent definitions of a traumatic event and of posttraumatic symptoms. Available online for purchase or by subscription.

  • Weisaeth, Lars. 2014. The history of psychic trauma. In Handbook of PTSD: Science in practice. 2d ed. Edited by Matthew J. Friedman, Terence M. Keane, and Patricia A. Resick, 38–59. New York: Guilford Press.

    Provides an overview of the origins of the clinical and scientific study of traumatic stress from the 19th century to the early 21st century.

  • Wilson, John P. 1994. The historical evolution of PTSD diagnostic criteria: From Freud to DSM-IV. Journal of Traumatic Stress 7.4: 681–698.

    DOI: 10.1002/jts.2490070413

    Reviews Sigmund Freud’s descriptions of reactions to trauma and traces these through the development of the various editions of the American Psychiatric Association’s Diagnostic and Statistical Manual. Available online for purchase or by subscription.

  • Young, Allan. 1995. The harmony of illusions: Inventing post-traumatic stress disorder. Princeton, NJ: Princeton Univ. Press.

    Argues that PTSD is not a timeless or universal phenomenon newly discovered; rather, it is a cultural product gradually put together by the practices, technologies, and narratives with which it is diagnosed, studied, and treated by the various interests, institutions, and moral arguments mobilizing these efforts.

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