Psychological trauma
Psychological trauma is a type of damage to the psyche that occurs as a result of a traumatic event. When that trauma leads to Post Traumatic Stress Disorder, damage can be measured in physical changes inside the brain and to brain chemistry, which affect the person's ability to cope with stress.
A traumatic event involves a single experience, or an enduring or repeating event or events, that completely overwhelm the individual's ability to cope or integrate the ideas and emotions involved with that experience. The sense of being overwhelmed can be delayed by weeks or years, as the person struggles to cope with the immediate danger. Trauma can be caused by a wide variety of events, but there are a few common aspects. It usually involves a feeling of complete helplessness in the face of a real or subjective threat to one's life or to that of loved ones, to bodily integrity, or sanity. There is frequently a violation of the person's familiar ideas about the world and of their human rights, putting the person in a state of extreme confusion and insecurity. This is also seen when people or institutions depended on for survival violate or betray the person in some unforeseen way.
Psychological trauma may accompany physical trauma or exist independently of it. Typical causes of psychological trauma are sexual abuse, violence, the threat of either, or the witnessing of either, particularly in childhood. Catastrophic events such as earthquakes and volcanic eruptions, war or other mass violence can also cause psychological trauma. Long-term exposure to situations such as extreme poverty or milder forms of abuse, such as verbal abuse, can be traumatic (though verbal abuse can also potentially be traumatic as a single event). In some cases, even a person's own actions, such as committing rape, can be traumatic if the offender feels helpless to control the urge to commit such crimes.
However, different people will react differently to similar events. One person may perceive an event to be traumatic that another may not, and not all people who experience a traumatic event will become psychologically traumatized.

# Symptoms of trauma
People who go through traumatic experiences often have certain symptoms and problems afterward. How severe these symptoms are depends on the person, the type of trauma involved, and the emotional support they receive from others. This section is a general listing of possible symptoms, and is not exhaustive. Reactions to and symptoms of trauma can be wide and varied, and differ in severity from person to person. A traumatized individual may experience one or several of them.
After a traumatic experience, a person may re-experience the trauma mentally and physically, hence avoiding trauma reminders, as this can be uncomfortable and even painful. They may turn to alcohol and/or drugs to try and escape the feelings. Re-experiencing symptoms are a sign that the body and mind are actively struggling to cope with the traumatic experience. Emotional triggers and cues act as reminders of the trauma, and can cause anxiety and other associated emotions. Often the person can be completely unaware of what these triggers are. In many cases this may lead a person suffering from traumatic disorders to engage in disruptive or self-destructive coping mechanisms, often without being fully aware of the nature or causes of their own actions. Panic attacks are an example of a psychosomatic response to such emotional triggers.
Consequently, intense feelings of anger may surface frequently, sometimes in very inappropriate or unexpected situations, as danger may always seem to be present. Upsetting memories such as images, thoughts, or flashbacks may haunt the person, and nightmares may be frequent. Insomnia may occur as lurking fears and insecurity keep the person vigilant and on the lookout for danger, both day and night.
In time, emotional exhaustion may set in, leading to distraction, and clear thinking may be difficult or impossible. Emotional detachment, also known as dissociation or "numbing out", can frequently occur. Dissociating from the painful emotion includes numbing all emotion, and the person may seem emotionally flat, preoccupied or distant. The person can become confused in ordinary situations and have memory problems.
Some traumatized people may feel permanently damaged when trauma symptoms don't go away and they don't believe their situation will improve. This can lead to feelings of despair, loss of self-esteem, and frequently depression. If important aspects of the person's self and world understanding have been violated, the person may call their own identity into question.
These symptoms can lead to stress or anxiety disorders, or even post traumatic stress disorder, where the person experiences flashbacks and re-experiences the emotion of the trauma as if it is actually happening.

# Situational Trauma
Trauma is well-known in genocide, war, and crime situations. It is almost always seen in torture victims and targets of mobbing (see psychology of torture). It also occurs in natural and man-made disasters, catastrophic mishaps, and medical emergencies. Here treatment for trauma is often either not sought, or is not available. It is common, but less often identified in situations of domestic violence, pedophilia, and incest. It also occurs in victims of child or elder abuse. Victims in situations of pedophilia, domestic violence, and neglect are often not identified by caregivers and are also unlikely to receive proper treatment for ongoing trauma.
Trauma is often defined as a coping response to and a consequence of overwhelming situations. However, as an individual's sense of being "overwhelmed" is subjective, the occurrence of trauma is also subjective. There is evidence to suggest that how people cope with extremely stressful situations is associated to the amount of trauma suffered from such events.

## Experiences that may induce the condition
For an event to have a traumatizing effect it is not necessary that physical damage occurs. Regardless of the source of the trauma, the experience has four common traits: it was unexpected, it was psychologically overwhelming, the person was unprepared or unable to cope with it, and there was nothing the person felt they could do to prevent or mitigate it. It is thus, not the event per se that determines whether an experience is traumatic, but the subjective experience of that person. Examples of situations which may be experienced as psychologically traumatic by some individuals include.
- childhood physical, emotional, or sexual abuse, including prolonged or extreme neglect; also, witnessing such abuse inflicted on another child or an adult.
- Experiences and interactions that are experienced as psychological "attacks"; for example a continual perception of psychological force, invalidation or annihilation.
- experiencing an event perceived as life-threatening, such as but not limited to:
- automobile or other serious accident,
- a vicious attack by an animal,
- medical complications,
- violent physical assaults or surviving or witnessing a terrorist attack,
- adult experiences of sexual assault or rape
- experiencing or witnessing physical or psychological torture
- civilian experiences of warfare or ethnic cleansing
- combatant experiences of warfare (also referred to as combat stress reaction)
- occupational experiences, such as through police work or fire fighting
- living through a natural catastrophe, such as a tornado, tsunami, or severe earthquake

### Cancer as PTSD-trauma
PTSD is normally associated with trauma such as violent crimes, rape, and war experience.  However, there have been a growing number of reports of PTSD among cancer survivors and their relatives (Smith 1999, Kangas 2002).  Most studies deal with survivors of breast cancer (Green 1998, Cordova 2000, Amir & Ramati 2002), and cancer in children and their parents (Landolt 1998, Stuber 1998), and show prevalence figures of between five and 20%.  Characteristic intrusive and avoidance symptoms have been described in cancer patients with traumatic memories of injury, treatment, and death (Brewin 1998).  There is yet disagreement on whether the traumas associated with different stressful events relating to cancer diagnosis and treatment actually qualify as PTSD stressors (Green 1998).  Cancer as trauma is multifaceted, includes multiple events that can cause distress, and like combat, is often characterized by extended duration with a potential for recurrence and a varying immediacy of life-threat (Smith 1999).

# Responses to psychological trauma
There are several behavioral responses common towards stressors including the proactive, reactive, and passive responses. Proactive responses include attempts to address and correct a stressor before it has a noticeable effect on lifestyle.  Reactive responses occur after the stress and possible trauma has occurred, and are aimed more at correcting or minimizing the damage of a stressful event.  A passive response is often characterized by an emotional numbness or ignorance of a stressor. Those who are able to be proactive can often overcome stressors and are more likely to be able to cope well with unexpected situations.  On the other hand, those who are more reactive will often experience more noticeable effects from an unexpected stressor. In the case of those who are passive, victims of a stressful event are more likely to suffer from long term traumatic effects and often enact no intentional coping actions. These observations may suggest that the level of trauma associated with a victim is related to such independent coping abilities.
There is also a distinction between trauma induced by recent situations and long-term trauma which may have been buried in the unconscious from past situations such as childhood abuse.
Trauma is often overcome through healing; in some cases this can be achieved by recreating or revisting the origin of the trauma under more psychologically safe circumstances, such as with a therapist.

# Trauma in psychoanalysis
French neurologist Jean-Martin Charcot argued that psychological trauma was the origin of all instances of the mental illness known as hysteria.  Charcot's "traumatic hysteria" often manifested as a paralysis that followed a physical trauma, typically years later after what Charcot described as a period of "incubation" .
Sigmund Freud, Charcot's student and the father of psychoanalysis, examined the concept of psychological trauma throughout his career.  Jean Laplanche has given a general description of Freud's understanding of trauma, which varied significantly over the course of Freud's career: "An event in the subject's life, defined by its intensity, by the subject's incapacity to respond adequately to it and by the upheaval and long-lasting effects that it brings about in the psychical organization" .

# Trauma and stress disorders
In times of war, psychological trauma has been known as shell shock or combat stress reaction (CSR). Psychological trauma may cause acute stress disorder (ASD) which may lead on to posttraumatic stress disorder (PTSD). PTSD can also develop without an antecedent ASD and may come on months or years after the trauma. Both ASD and PTSD are specific disorders in which the traumatized individual may experience nightmares, avoidance of certain situations and places, depression, and symptoms of hyper-activation.  PTSD emerged as the label for this condition after the Vietnam War in which many veterans returned to their respective countries demoralized, and sometimes, addicted to drugs.
Psychological trauma is treated with therapy and, if indicated, psychotropic medications.  Recent studies try to show the effect of trauma on human memory. This kind of study is useful in order to verify the attendibility of eyewitnesses involved in criminal acts.
Therapies used in the treatment of psychological trauma include: Cognitive therapy (CBT), Brief therapy, Psychodynamic psychotherapy, Play therapy, Traumatic Incident Reduction (TIR), EMDR, and Dialectical behavioral therapy (DBT).
Following traumatic events, persons involved are often asked to talk about the events soon after, sometimes even immediately after the event occurred in order to start a healing process.  This practice may not garner the positive results needed to recover psychologically from a traumatic event.  Victims of traumatic occurrences who were debriefed immediately after the event in general do fare better than others who received therapy at a later time. Yet, there is one indication that forcing immediate debriefing may even distort the natural psychological healing process .

# Growth aspects of trauma
Though the idea of trauma is most frequently thought of in negative terms, it is also often seen to have positive aspects. Many people, such as Christopher Reeve and Rick Hansen, have overcome traumas and moved on to become inspirational figures. This growth, first called posttraumatic growth in 1996 by psychologists Richard Tedeschi and Lawrence Calhoun, can involve changes in how people think of themselves, their relationships with others, including all of humanity, as well as profound philosophical, spiritual, or religious changes.
According to Lawrence G. Calhoun and Richard Tedeschi, both professors at the University of North Carolina at Charlotte, trauma experiences can lead to growth, though this is not inevitable.  They have found that "reports of growth experiences in the aftermath of traumatic events far outnumber reports of psychiatric disorders." They state that these changes can include
...improved relationships, new possibilities for one's life, a greater appreciation for life, a greater sense of personal strength and spiritual development. There appears to be a basic paradox apprehended by trauma survivors who report these aspects of posttraumatic growth: Their losses have produced valuable gains ...They also may find themselves becoming more comfortable with intimacy and having a greater sense of compassion for others who experience life difficulties.
Still, they add, "posttraumatic growth does not necessarily yield less emotional distress."
...posttraumatic growth occurs in the context of suffering and significant psychological struggle, and a focus on this growth should not come at the expense of empathy for the pain and suffering of trauma survivors. For most trauma survivors, posttraumatic growth and distress will coexist, and the growth emerges from the struggle with coping, not from the trauma itself.
They point out that "there are also a significant number of people who experience little or no growth in their struggle with trauma."