Posttraumatic stress disorder: an overview // national center for post-traumatic stress disorder
Posttraumatic Stress Disorder: An Overview // National Center for Post-Traumatic Stress Disorder
Posttraumatic Stress Disorder: An Overview
Matthew J. Friedman, M.D., Ph.D., Executive Director, National Center for PTSD
Professor of Psychiatry and Pharmacology, Dartmouth Medical School
A brief history of the PTSD diagnosis
The risk of exposure to trauma has been a part of the human condition since we evolved as
a species. Attacks by saber tooth tigers or twenty-first century terrorists have probably
produced similar psychological sequelae in the survivors of such violence. Shakespeare's
Henry IV appears to meet many, if not all, of the diagnostic criteria for Posttraumatic Stress
Disorder (PTSD), as have other heroes and heroines throughout the world's literature. The
history of the development of the PTSD concept is described by Trimble (1985).
In 1980, the American Psychiatric Association added PTSD to the third edition of its
Diagnostic and Statistical Manual of Mental Disorders (DSM-III) nosologic classification
scheme. Although controversial when first introduced, the PTSD diagnosis has filled an
important gap in psychiatric theory and practice. From an historical perspective, the
significant change ushered in by the PTSD concept was the stipulation that the etiological
agent was outside the individual (i.e., a traumatic event) rather than an inherent individual
weakness (i.e., a traumatic neurosis). The key to understanding the scientific basis and
clinical expression of PTSD is the concept of "trauma."
In its initial DSM-III formulation, a traumatic event was conceptualized as a catastrophic
stressor that was outside the range of usual human experience. The framers of the original
PTSD diagnosis had in mind events such as war, torture, rape, the Nazi Holocaust, the
atomic bombings of Hiroshima and Nagasaki, natural disasters (such as earthquakes,
hurricanes, and volcano eruptions), and human-made disasters (such as factory explosions,
airplane crashes, and automobile accidents). They considered traumatic events to be clearly
different from the very painful stressors that constitute the normal vicissitudes of life such
as divorce, failure, rejection, serious illness, financial reverses, and the like. (By this logic,
adverse psychological responses to such "ordinary stressors" would, in DSM-III terms, be
characterized as Adjustment Disorders rather than PTSD.) This dichotomization between
traumatic and other stressors was based on the assumption that, although most individuals
have the ability to cope with ordinary stress, their adaptive capacities are likely to be
overwhelmed when confronted by a traumatic stressor.
PTSD is unique among psychiatric diagnoses because of the great importance placed upon
the etiological agent, the traumatic stressor. In fact, one cannot make a PTSD diagnosis
unless the patient has actually met the "stressor criterion," which means that he or she has
been exposed to an historical event that is considered traumatic. Clinical experience with the
PTSD diagnosis has shown, however, that there are individual differences regarding the
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capacity to cope with catastrophic stress. Therefore, while some people exposed to
traumatic events do not develop PTSD, others go on to develop the full-blown syndrome.
Such observations have prompted the recognition that trauma, like pain, is not an external
phenomenon that can be completely objectified. Like pain, the traumatic experience is
filtered through cognitive and emotional processes before it can be appraised as an extreme
threat. Because of individual differences in this appraisal process, different people appear to
have different trauma thresholds, some more protected from and some more vulnerable to
developing clinical symptoms after exposure to extremely stressful situations. Although
there is currently a renewed interest in subjective aspects of traumatic exposure, it must be
emphasized that events such as rape, torture, genocide, and severe war zone stress are
experienced as traumatic events by nearly everyone.
The DSM-III diagnostic criteria for PTSD were revised in DSM-III-R (1987), DSM-IV (1994),
and DSM-IV-TR (2000). A very similar syndrome is classified in ICD-10 (The ICD-10
Classification of Mental and Behavioural Disorders: Clinical Descriptions and Diagnostic
Guidelines). Diagnostic criteria for PTSD include a history of exposure to a traumatic event
and symptoms from each of three symptom clusters: intrusive recollections, avoidant/
numbing symptoms, and hyper-arousal symptoms. A fifth criterion concerns duration of
symptoms. One important finding, which was not apparent when PTSD was first proposed as
a diagnosis in 1980, is that it is relatively common. Recent data from the national
comorbidity survey indicates PTSD prevalence rates are 5% and 10% respectively among
American men and women (Kessler et al., 1996). Rates of PTSD are much higher in
postconflict settings such as Algeria (37%), Cambodia (28%), Ethiopia (16%), and Gaza
Criteria for a PTSD diagnosis
As noted above, the "A" stressor criterion specifies that a person has been exposed to a
catastrophic event involving actual or threatened death or injury, or a threat to the physical
integrity of him/herself or others. During this traumatic exposure, the survivor's subjective
response was marked by intense fear, helplessness, or horror.
The "B", or intrusive recollection, criterion includes symptoms that are perhaps the most
distinctive and readily identifiable symptoms of PTSD. For individuals with PTSD, the
traumatic event remains, sometimes for decades or a lifetime, a dominating psychological
experience that retains its power to evoke panic, terror, dread, grief, or despair. These
emotions manifest in daytime fantasies, traumatic nightmares, and psychotic reenactments
known as PTSD flashbacks. Furthermore, trauma-related stimuli that trigger recollections of
the original event have the power to evoke mental images, emotional responses, and
psychological reactions associated with the trauma. Researchers can use this phenomenon
to reproduce PTSD symptoms in the laboratory by exposing affected individuals to auditory
or visual trauma-related stimuli (Keane et. al., 1987).
The "C", or avoidant/numbing, criterion consists of symptoms that reflect behavioral,
cognitive, or emotional strategies PTSD patients use in an attempt to reduce the likelihood
that they will expose themselves to trauma-related stimuli. PTSD patients also use these
strategies in an attempt to minimize the intensity of their psychological response if they are
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exposed to such stimuli. Behavioral strategies include avoiding any situation in which they
perceive a risk of confronting trauma-related stimuli. In its extreme manifestation, avoidant
behavior may superficially resemble agoraphobia because the PTSD individual is afraid to
leave the house for fear of confronting reminders of the traumatic event(s). Dissociation and
psychogenic amnesia are included among the avoidant/numbing symptoms and involve the
individuals cutting off the conscious experience of trauma-based memories and feelings.
Finally, since individuals with PTSD cannot tolerate strong emotions, especially those
associated with the traumatic experience, they separate the cognitive from the emotional
aspects of psychological experience and perceive only the former. Such "psychic numbing" is
an emotional anesthesia that makes it extremely difficult for people with PTSD to participate
in meaningful interpersonal relationships.
Symptoms included in the "D", or hyper-arousal, criterion most closely resemble those seen
in panic and generalized anxiety disorders. While symptoms such as insomnia and irritability
are generic anxiety symptoms, hyper-vigilance and startle are more characteristic of PTSD.
The hyper-vigilance in PTSD may sometimes become so intense as to appear like frank
paranoia. The startle response has a unique neurobiological substrate and may actually be
The "E", or duration, criterion specifies how long symptoms must persist in order to qualify
for the (chronic or delayed) PTSD diagnosis. In DSM-III, the mandatory duration was six
months. In DSM-III-R, the duration was shortened to one month, which it has remained.
The "F", or functional significance, criterion specifies that the survivor must experience
significant social, occupational, or other distress as a result of these symptoms.
Assessing PTSD
Since 1980, there has been a great deal of attention devoted to the development of
instruments for assessing PTSD. Keane and associates (1987) working, with Vietnam war-
zone veterans, have developed both psychometric and psychophysiologic assessment
techniques that have proven to be both valid and reliable. Other investigators have modified
such assessment instruments and used them with natural disaster victims, rape/incest
survivors, and other traumatized individuals. These assessment techniques have been used
in the epidemiological studies mentioned above and in other research protocols.
Neurobiological research indicates that PTSD may be associated with stable
neurobiologicalalterations in both the central and autonomic nervous systems.
Psychophysiological alterations associated with PTSD include hyper-arousal of the
sympathetic nervous system, increased sensitivity and augmentation of the acoustic-startle
eye blink reflex, a reducer pattern of auditory evoked cortical potentials, and sleep
abnormalities. Neuropharmacologic and neuroendocrine abnormalities have been detected in
most brain mechanisms that have evolved for coping, adaptation, and preservation of the
species. These include the noradrenergic, hypothalamic-pituitary-adrenocortical,
serotonergic, glutamatergic, thyroid, endogenous opioid, and other systems. This
information is reviewed extensively elsewhere (Friedman, Charney & Deutch, 1995;
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Longitudinal research has shown that PTSD can become a chronic psychiatric disorder and
can persist for decades and sometimes for a lifetime. Patients with chronic PTSD often
exhibit a longitudinal course marked by remissions and relapses. There is also a delayed
variant of PTSD in which individuals exposed to a traumatic event do not exhibit the PTSD
syndrome until months or years afterward. Usually, the immediate precipitant is a situation
that resembles the original trauma in a significant way (for example, a war veteran whose
child is deployed to a war zone or a rape survivor who is sexually harassed or assaulted
If an individual meets diagnostic criteria for PTSD, it is likely that he or she will meet DSM-
IV-TR criteria for one or more additional diagnoses (Kulka et. al., 1990; Davidson & Foa,
1993). Most often, these comorbid diagnoses include major affective disorders, dysthymia,
alcohol or substance abuse disorders, anxiety disorders, or personality disorders. There is a
legitimate question whether the high rate of diagnostic comorbidity seen with PTSD is an
artifact of our current decision-making rules for the PTSD diagnosis since there are not
exclusionary criteria in DSM-III-R. In any case, high rates of comorbidity complicate
treatment decisions concerning patients with PTSD since the clinician must decide whether
to treat the comorbid disorders concurrently or sequentially.
Although PTSD continues to be classified as an Anxiety Disorder, areas of disagreement
about its nosology and phenomenology remain. Questions about the syndrome itself include:
what is the clinical course of untreated PTSD; are there different subtypes of PTSD; what is
the distinction between traumatic simple phobia and PTSD; and what is the clinical
phenomenology of prolonged and repeated trauma? With regard to the latter, Herman
(1992) has argued that the current PTSD formulation fails to characterize the major
symptoms of PTSD commonly seen in victims of prolonged, repeated interpersonal violence
such as domestic or sexual abuse and political torture. She has proposed an alternative
diagnostic formulation that emphasizes multiple symptoms, excessive somatization,
dissociation, changes in affect, pathological changes in relationships, and pathological
PTSD has also been criticized from the perspective of cross-cultural psychology and medical
anthropology, especially with respect to refugees, asylum seekers, and political torture
victims from non-Western regions. Clinicians and researchers working with such survivors
argue that since PTSD has usually been diagnosed by clinicians from Western industrialized
nations working with patients from a similar background, the diagnosis does not accurately
reflect the clinical picture of traumatized individuals from non-Western traditional societies
and cultures. Major gaps remain in our understanding of the effects of ethnicity and culture
on the clinical phenomenology of posttraumatic syndromes. We have only just begun to
apply vigorous ethnocultural research strategies to delineate possible differences between
Western and non-Western societies regarding the psychological impact of traumatic
exposure and the clinical manifestations of such exposure (Marsella et. al., 1996).
Treatment for PTSD
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The many therapeutic approaches offered to PTSD patients are presented in Foa, Keane, and
Friedman's (2000) comprehensive book on treatment. The most successful interventions are
cognitive-behavioral therapy (CBT) and medication. Excellent results have been obtained
with some CBT combinations of exposure therapy and cognitive restructuring, especially with
female victims of childhood or adult sexual trauma. Sertraline (Zoloft) and paroxetine (Paxil)
are selective serotonin reuptake inhibitors (SSRI) that are the first medications to have
received FDA approval as indicated treatments for PTSD. Success has also been reported
with Eye Movement Desensitization and Reprocessing (EMDR), although rigorous scientific
data are lacking and it is unclear whether this approach is as effective as CBT.
Perhaps the best therapeutic option for mildly to moderately affected PTSD patients is group
therapy. In such a setting, the PTSD patient can discuss traumatic memories, PTSD
symptoms, and functional deficits with others who have had similar experiences. This
approach has been most successful with war veterans, rape/incest victims, and natural
disaster survivors. It is important that therapeutic goals be realistic because, in some cases,
PTSD is a chronic and severely debilitating psychiatric disorder that is refractory to current
available treatments. The hope remains, however, that our growing knowledge about PTSD
will enable us to design interventions that are more effective for all patients afflicted with
There is great interest in rapid interventions for acutely traumatized individuals, especially
with respect to civilian disasters, military deployments, and emergency personnel (medical
personnel, police, and firefighters). This has become a major policy and public health issue
since the massive traumatization caused by the September 11 terrorist attacks on the World
Trade Center. Currently, there is controversy about which interventions work best during the
immediate aftermath of a trauma. Research on critical incident stress debriefing (CISD), an
intervention used widely, has brought disappointing results with respect to its efficacy to
attenuate posttraumatic distress or to forestall the later development of PTSD. Promising
results have been shown with brief cognitive-behavioral therapy.
Further information on PTSD is readily accessible through this website. References
Davidson, J.R.T., & Foa, E.B (Eds.). (1993). Posttraumatic Stress Disorder: DSM-IV and beyond. Washington, DC: American Psychiatric Press.
De Jong, J., Komproe, T.V.M., Ivan, H., von Ommeren, M., El Masri, M., Araya, M., Khaled,
N., van de Put, W., & Somasundarem, D.J. (2001). Lifetime events and Posttraumatic Stress
Disorder in 4 postconflict settings. Journal of the American Medical Association, 286 (5), 555-
Foa, E.B., Keane, T.M., & Friedman, M.J. (2000). Effective treatments for PTSD: Practice guidelines from the International Society for Traumatic Stress Studies. New York: Guilford
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Posttraumatic Stress Disorder: An Overview // National Center for Post-Traumatic Stress Disorder
Foa, E.B., Zinbarg, R., & Rothbaum, B.O. (1992). Uncontrollability and unpredictability of
Post-traumatic Stress Disorder: An animal model. Psychological Bulletin, 112, 218-238.
Friedman, M.J., Charney, D.S. & Deutch, A.Y. (1995) Neurobiological and clinical consequences of stress: From normal adaptation to PTSD. Philadelphia: Lippincott-Raven.
Herman, J.L. (1992). Trauma and recovery. New York: Basic Books.
Keane, T.M., Wolfe, J., & Taylor, K.I. (1987). Post-traumatic Stress Disorder: Evidence for
diagnostic validity and methods of psychological assessment. Journal of Clinical Psychology,
Kessler, R.C., Sonnega, A., Bromet, E., Hughes, M. & Nelson, C.B. (1996). Posttraumatic
Stress Disorder in the National Comorbidity Survey. Archives of General Psychiatry, 52,
Kulka, R.A., Schlenger, W.E., Fairbank, J.A., Hough, R.L., Jordan, B.K., Marmar, C.R., &
Weiss, D.S. (1990). Trauma and the Vietnam War generation. New York: Brunner/Mazel.
Marsella, A.J., Friedman, M.J., Gerrity, E. & Scurfield R.M. (Eds.). (1996). Ethnocultural aspects of Post-Traumatic Stress Disorders: Issues, research and applications. Washington,
Trimble, M.D. (1985). Post-traumatic Stress Disorder: History of a concept. In C.R. Figley
(Ed.), Trauma and its wake: The study and treatment of Post-Traumatic Stress Disorder.
Revised from Encyclopedia of Psychology, R. Corsini, Ed. (New York: Wiley, 1984, 1994)
DSM-IV-TR criteria for PTSD
A. The person has been exposed to a traumatic event in which both of the following have
1. the person has experienced, witnessed, or been confronted with an event or events that
involve actual or threatened death or serious injury, or a threat to the physical integrity of
2. the person's response involved intense fear, helplessness, or horror. Note: in children, it
may be expressed instead by disorganized or agitated behavior.
B. The traumatic event is persistently re-experienced in at least one of the following ways:
1. recurrent and intrusive distressing recollections of the event, including images, thoughts,
or perceptions. Note: in young children, repetitive play may occur in which themes or
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2. recurrent distressing dreams of the event. Note: in children, there may be frightening
3. acting or feeling as if the traumatic event were recurring (includes a sense of reliving the
experience, illusions, hallucinations, and dissociative flashback episodes, including those that
occur upon awakening or when intoxicated). Note: in children, trauma-specific reenactment
4. intense psychological distress at exposure to internal or external cues that symbolize or
resemble an aspect of the traumatic event.
5. physiologic reactivity upon exposure to internal or external cues that symbolize or
resemble an aspect of the traumatic event
C. Persistent avoidance of stimuli associated with the trauma and numbing of general
responsiveness (not present before the trauma), as indicated by at least three of the
1. efforts to avoid thoughts, feelings, or conversations associated with the trauma
2. efforts to avoid activities, places, or people that arouse recollections of the trauma
3. inability to recall an important aspect of the trauma
4. markedly diminished interest or participation in significant activities
5. feeling of detachment or estrangement from others
6. restricted range of affect (e.g., unable to have loving feelings)
7. sense of foreshortened future (e.g., does not expect to have a career, marriage, children,
D. Persistent symptoms of increasing arousal (not present before the trauma), indicated by
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E. Duration of the disturbance (symptoms in B, C, and D) is more than one month.
F. The disturbance causes clinically significant distress or impairment in social, occupational,
or other important areas of functioning. Specify if: Acute: if duration of symptoms is less than three months Chronic: if duration of symptoms is three months or more Specify if: Without delay onset: onset of symptoms at least six months after the stressor
The information on this Web site is presented for educational purposes only. It is not a substitute for informed medical advice or training. Do not use this information to diagnose or treat a mental health problem without consulting a qualified health or mental health care provider.
All information contained on these pages is in the public domain unless explicit notice is given to the contrary, and may be copied and distributed without restriction.
For more information call the PTSD Information Line at (802) 296-6300 or send email to . This page was last updated on Wed
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Yaws in the periurban settlements of Port Moresby, Papua New Guinea HOPE worldwide (PNG), Port Moresby, Papua New Guinea Yaws is a re-emerging disease in Papua New Guinea. A resurgence of yaws is documented in the periurban settlements around Port Moresby. A total of 494 cases were identified from April 2000 to September 2001. The age distribution ranged from 2 years to adult (median