Post-traumatic stress disorder (PTSD) is a medically recognized disorder that occurs in normal individuals under extremely stressful conditions. Its symptoms affect people from all walks of life, including soldiers, victims of natural disasters or serious accidents. PTSD can affect people who provide emergency services for others. Some individuals who survive a traumatic event are affected so strongly by the experience that they are unable to live normal lives.

What are the symptoms of PTSD?

There are four main types of PTSD symptoms. A diagnosis of PTSD requires the presence of all categories of symptomatic responses:

• re-experiencing the trauma: flashbacks, nightmares, intrusive memories and exaggerated emotional and physical reactions to triggers that remind the person of the trauma.
• emotional numbing: feeling detached, lack of emotions (especially positive ones), loss of interest in activities
• avoidance: avoiding activities, people, or places that remind the person of the trauma
• increased arousal: difficulty sleeping and concentrating, irritability, hypervigilance (being on guard), and exaggerated startle response.

How do animal studies help us understand PTSD and its symptoms?

There is increasing evidence that the symptoms of PTSD are abnormal responses to stress. According to trauma authority Dr. Peter Levine, traumatic symptoms are not caused by the dangerous event itself. These symptoms arise when residual energy from the event is not discharged from the body, but remains trapped in the nervous system where it can wreak havoc on our bodies and minds.

Levine observes that wild prey animals, though threatened routinely, are rarely traumatized. Animals in the wild utilize innate mechanisms to regulate and discharge the high levels of energy arousal associated with defensive survival behaviors. These mechanisms provide animals with a built-in ''immunity'' to trauma that enables them to return to normal in the aftermath of highly ''charged'' life-threatening experiences.

Although humans are born with virtually the same regulatory mechanisms as animals, the function of these instinctive systems is often overridden or inhibited. This restraint prevents the complete discharge of survival energies, and does not allow the nervous system to regain its equilibrium. From this perspective:

• ‘traumatic panic anxiety’ symptom occurs where normally varied and active defensive responses have been unsuccessful – when a situation, perceived as both dangerous and inescapable, results in a profound failure of innate defenses.
• un-discharged “survival energy” remains “stuck” in the body and the nervous system – sympathetic and parasympathetic responses are concurrently activated, like brake and accelerator, working against each other.
• symptoms of trauma result from the body's attempt to ''manage'' and contain this unused energy.
• healing the symptoms of PTSD is accomplished by normalizing defense responses – by progressively re-establishing the pre-traumatic defensive and orienting responses that were in execution just prior to the initiation of immobility.

In summary, when the normal defensive resources fail to resolve the situation, terror- panic, rage and freezing occur. These emotional anxiety states are evoked when the feelings of danger-orientation and preparedness to flee are blocked or inhibited. It is this “thwarting” that results in freezing and anxiety-panic symptoms associated with PTSD.

What are the consequences of PTSD?

PTSD can have severe and long lasting effects on people's lives. Examples of outcomes of PTSD are:

Physiological outcomes

• neurobiological changes (alterations in brainwave activity, in size of brain structures, and in functioning of processes such as memory and fear response)
• psychophysiological changes (hyper-arousal of the sympathetic nervous system, increased startle, sleep disturbances, increased neurohormonal changes that result in heightened stress and increased depression)
• physical complaints that are often treated symptomatically, rather than as indications of PTSD (headaches, stomach or digestive problems, immune system problems, asthma or breathing problems, dizziness, chest pain, chronic pain or fibromyalgia)

Psychological outcomes

• depression (major depressive episodes, or pervasive depression)
• other anxiety disorders (such as phobias, panic, and social anxiety)
• conduct disorders
• dissociation ("splitting off" from the present, and into parts of the self)
• eating disorders

Social outcomes

• interpersonal problems
• low self esteem
• alcohol and substance use
• employment problems
• homelessness
• trouble with the law

Self-destructive behaviors

• substance abuse
• suicidal attempts
• risky sexual behaviors leading to unplanned pregnancy or STDs, including HIV
• reckless driving
• self-injury

What is Complex PTSD?

Prolonged, extreme traumatic circumstances — such as childhood sexual abuse, prisoner of war camps, or long-term domestic violence — can cause a form of PTSD called Complex PTSD. As in PTSD, ordinary, healthy persons under severe circumstances can experience changes in how they adapt to stress and how they view themselves. A mental health diagnosis called Borderline Personality Disorder is also highly indicative of a history of trauma, and is increasingly viewed as a type of Complex PTSD.

Possible symptoms of Complex PTSD are:

• severe behavioral difficulties (such as alcohol/drug abuse, aggression, eating disorders)
• difficulty in controlling intense emotions (such as anger, panic, or depression)
• other mental difficulties (such as amnesia or dissociation — a serious condition called Dissociative Identity Disorder, formerly known as Multiple Personality Disorder, which is characterized by "splitting off" parts of oneself