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Posttraumatic Stress Disorder (PTSD)

By John H. Greist, MD, Clinical Professor of Psychiatry;Distinguished Senior Scientist, University of Wisconsin School of Medicine and Public Health;Madison Institute of Medicine

Posttraumatic stress disorder (PTSD) is characterized by recurrent, intrusive recollections of an overwhelming traumatic event. Recollections recur for more than 1 month and begin within 6 months of the event.

  • Events that threaten death or serious injury can cause intense, long-lasting distress.

  • Affected people may relive the event, have nightmares, and avoid anything that reminds them of the event.

  • Treatment may include psychotherapy (supportive and exposure therapy) and antidepressants.

Traumatic events that threaten death or serious injury can affect people long after the experience is over. People may experience the event directly (for example, when people are seriously injured) or indirectly (for example, when people witness a murder or learn that close family members or friends have experienced a traumatic event). Intense fear, helplessness, or horror experienced during the traumatic event can haunt them.

Events that can lead to posttraumatic stress disorder include the following:

  • Engaging in combat

  • Experiencing or witnessing sexual or physical assault

  • Experiencing a disaster, either natural (for example, a hurricane) or man-made (for example, a severe automobile accident)

Posttraumatic stress disorder affects almost 9% of people sometime during their life, including childhood (see Acute and Posttraumatic Stress Disorders in Children and Adolescents). About 4% have it during any 12-month period. Many people who undergo or witness traumatic events, such as combat veterans and victims of rape or other violent acts, develop posttraumatic stress disorder.

Posttraumatic stress disorder lasts for more than 1 month. It may be a continuation of acute stress disorder or develop separately up to 6 months after the event.

Chronic posttraumatic stress disorder may not disappear but often becomes less intense over time even without treatment. Nevertheless, some people remain severely handicapped by the disorder.


In posttraumatic stress disorder, people have several types of symptoms:

  • Intrusion symptoms (the event repeatedly and uncontrollably invades in their thoughts)

  • Avoidance of anything that reminds them of the event

  • Negative effects on thinking and mood

  • Changes in alertness and reactions

Intrusion symptoms

People have frequent, unwanted memories replaying the traumatic event. Nightmares of the event are common. Much less often, people relive events as if they were actually happening (flashbacks) rather than simply being remembered. For example, loud fireworks might trigger a flashback or being in combat, causing the person to seek shelter or drop to the ground to protect themselves. People may become totally unaware of their present surroundings.

People often experience intense emotional and/or physical distress when they are exposed to an event or situation that reminds them of the original trauma. Examples of such reminders are anniversaries of the traumatic event, seeing a gun after being pistol-whipped during a robbery, and being in a small boat after a near-drowning accident.

Avoidance symptoms

People persistently avoid things—activities, situations, or people—that are reminders of the trauma. For example, they may avoid entering a park or an office building where they were assaulted or avoid speaking to people of the same race as their assailant. They may even attempt to avoid thoughts, feelings, or conversations about the traumatic event.

Negative effects on thinking and mood

People may be unable to remember significant parts of the traumatic event (called dissociative amnesia).

People may feel emotionally numb or disconnected from other people. Depression is common, and people show less interest in previously enjoyed activities.

How people think about the event may become distorted, leading them to blame themselves or others for what happened. Feelings of guilt are also common. For example, they may feel guilty that they survived when other people did not. They may feel only negative emotions, such as fear, horror, anger, or shame, and may be unable to feel happy or satisfied or to love.

Changes in alertness and reactions

People may have difficulty falling asleep or concentrating.

They may become excessively vigilant for warning signs of risk or be easily startled.

People may become less able to control their reactions, resulting in reckless behavior or angry outbursts.

Other symptoms

Some people develop ritual activities to help reduce their anxiety. For example, people who were sexually assaulted may bathe repeatedly to try to remove the sense of being unclean.


  • A doctor's evaluation, based on specific criteria

Doctors diagnose posttraumatic stress disorder when

  • People have been exposed directly or indirectly to a traumatic event.

  • Symptoms have been present for 1 month or longer.

  • Symptoms cause significant distress or significantly impair functioning.

  • People have some symptoms from each type of symptom associated with posttraumatic stress disorder (intrusion symptoms, avoidance symptoms, negative effects on thinking and mood, and changes in alertness and reactions).

Doctors also check to see whether symptoms could result from use of a drug or another disorder.


  • Psychotherapy, especially exposure therapy

  • Drug therapy

Treatment involves psychotherapy (particularly exposure therapy) and drug therapy.


In exposure therapy (see What Is Exposure Therapy?), the therapist has people imagine being in situations or with people that they avoid because they associate these situations and people with the trauma. For example, they may be asked to imagine visiting a park where they were assaulted. The therapist also helps people reimagine the traumatic event itself. Because of the often intense anxiety associated with traumatic memories, supportive psychotherapy plays an especially important role in treatment. The therapist is openly empathic and sympathetic in recognizing the psychologic pain. The therapist reassures people that their response is valid but encourages them to face their memories (as a form of exposure therapy). They are also taught ways to control anxiety, which help modulate and integrate the painful memories into their personality. Exposure therapy also includes preventing people from performing any of the rituals they have developed.

If people have survivor guilt, psychotherapy can help them understand and change their negative and distorted thoughts.

Eye movement desensitization and reprocessing (EMDR) is a form of exposure therapy. In EMDR, people follow the therapist's moving finger with their eyes while imagining being exposed to the trauma. Some experts think that the eye movements themselves help with desensitization, but EMDR probably works mainly because of the exposure, not the eye movements.

Drug therapy

Antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), are especially helpful.

Prazosin (also used to treat high blood pressure) may help reduce the number of nightmares.

Many other drugs, including drugs that stabilize mood (such as valproate) or treat psychotic disorders, have been tried, but whether they are effective is unclear.