Post traumatic stress disorder (PTSD) is a psychiatric disorder that may occur in people who have experienced or witnessed a traumatic event such as a natural disaster, a serious accident, a terrorist act, war/combat, or rape or who have been threatened with death, sexual violence or serious injury.

PTSD has been known by many names in the past, such as “shell shock” during the years of World War I and “combat fatigue” after World War II, but PTSD does not just happen to combat veterans. PTSD can occur in all people, of any ethnicity, nationality or culture, and at any age. PTSD affects approximately 3.5 percent of U.S. adults every year, and an estimated one in 11 people will be diagnosed with PTSD in their lifetime. Women are twice as likely as men to have PTSD. Three ethnic groups – U.S. Latinos, African Americans, and American Indians – are disproportionately affected and have higher rates of PTSD than non-Latino whites.

People with PTSD have intense, disturbing thoughts and feelings related to their experience that last long after the traumatic event has ended. They may relive the event through flashbacks or nightmares; they may feel sadness, fear or anger; and they may feel detached or estranged from other people. People with PTSD may avoid situations or people that remind them of the traumatic event, and they may have strong negative reactions to something as ordinary as a loud noise or an accidental touch.

Symptoms of PTSD fall into four categories. Specific symptoms can vary in severity.

1. Intrusion: Intrusive thoughts such as repeated, involuntary memories; distressing dreams; or flashbacks of the traumatic event. Flashbacks may be so vivid that people feel they are re-living the traumatic experience or seeing it before their eyes.
2. Avoidance: Avoiding reminders of the traumatic event may include avoiding people, places, activities, objects and situations that may trigger distressing memories. People may try to avoid remembering or thinking about the traumatic event. They may resist talking about what happened or how they feel about it.
3. Alterations in cognition and mood: Inability to remember important aspects of the traumatic event, negative thoughts and feelings leading to ongoing and distorted beliefs about oneself or others (e.g., “I am bad,” “No one can be trusted”); distorted thoughts about the cause or consequences of the event leading to wrongly blaming self or other; ongoing fear, horror, anger, guilt or shame; much less interest in activities previously enjoyed; feeling detached or estranged from others; or being unable to experience positive emotions (a void of happiness or satisfaction).
4. Alterations in arousal and reactivity: Arousal and reactive symptoms may include being irritable and having angry outbursts; behaving recklessly or in a self-destructive way; being overly watchful of one's surroundings in a suspecting way; being easily startled; or having problems concentrating or sleeping.

Many people who are exposed to a traumatic event experience symptoms similar to those described above in the days following the event. For a person to be diagnosed with PTSD, however, symptoms must last for more than a month and must cause significant distress or problems n the individual's daily functioning. Many individuals develop symptoms within three months of the trauma, but symptoms may appear later and often persist for months and sometimes years. PTSD often occurs with other related conditions, such as depression, substance use, memory problems and other physical and mental health problems.

American Psychiatric Association 2020