Current Trends in PTSD Research
NCP Clinical Quarterly 2(1): Fall 1991
The newsletter staff invited me to expand upon my usual column New Directions in PTSD to address how some of the current trends in PTSD research apply to the clinical issues of diagnosis and treatment. It’s my hope that this brief review will update the clinician currently treating PTSD patients. I’ll cover the following topics: epidemiology, diagnosis/assessment, biological approaches, treatment/outcome studies, risk factors for PTSD, possible medical complications from PTSD, and close by indicating what I consider the most important questions for future research.
Most of us are aware of the major findings from the National Vietnam Veterans Readjustment Study (NVVRS). According to Dr. Terry Keane, who reviewed this and other epidemiological studies on PTSD in the Fall, 1990 PTSD Research Quarterly, the NVVRS is "the most methodologically rigorous epidemiological study of psychological problems we've ever conducted in the United States." The profound and enduring impact of war-zone trauma is documented by the NVVRS estimate that 15.2% of all male and 8.5% of all female Vietnam theater veterans currently suffer from PTSD -- approximately 450,000 veterans in all. Furthermore, more than twice that number (30.6% male and 26.9% female) of theater veterans have had the full PTSD syndrome at some time since their war-zone experience in Southeast Asia. Such information has prompted action by the Department of Veterans Affairs (DVA) and the US Congress to create more clinical programs to treat PTSD. Additionally, NVVRS estimates that only 10% of veterans with current PTSD and 20% with lifetime PTSD have ever used VA facilities. This finding should force us to reconsider our current clinical approaches and motivate us to find more effective ways of making PTSD treatment more accessible and attractive to veterans. Finally, the NVVRS finding that current PTSD is found in 20.6% of Black and 27.9% of Hispanic theater veterans in contrast to 13.7% of predominantly White veterans should impel us to consider the question of how minority status may affect risk factors, clinical phenomenology, therapeutic approaches and willingness to seek treatment for PTSD.
Assessment is a rapidly growing aspect of PTSD research marked by the development of a number of diagnostic instruments useful in both research and clinical settings. It is clear that assessment of war-zone PTSD is farther along than assessment of other trauma syndromes. The old standbys, the SCID (Structured Clinical Interview for DSM-III-R), the MMPI-PTSD Scale, the Mississippi Scale for Combat related PTSD, and the Impact of Events Scale have several shortcomings, especially with regard to quantitating the magnitude of the response to treatment of specific PTSD. Two structured interviews have been recently developed that can be administered on a weekly basis to monitor the response to behavioral treatment, pharmacotherapy or other kinds of intervention. They are the SIPTSD (Structured Interview for PTSD) developed by Jonathan Davidson and associates at VAMC Durham and the CAPS (Clinician Administered PTSD Scale) by Dudley Blake and colleagues at the National Center. Jessica Wolfe of the National Center has collaborated with Joan Furey (NC staff) and Rose Sandecki (VAMC San Francisco) in developing the women's Military Exposure Scale to tap war-zone trauma, including combat exposure, criminal victimization and sexual victimization of female military veterans. Finally, in response to the Desert Shield/Desert Storm crisis, Brett Litz and colleagues at the National Center developed a structured interview for assessing PTSD in American hostages detained in Iraq and Kuwait, and in military personnel who fought in the Persian Gulf Theatre; Jessica Wolfe and National Center colleagues have modified the Mississippi Scale for Desert Storm returnees.
Other investigators working with patients exposed to civilian traumas like violent crime, natural disaster, sexual assault or childhood trauma have developed assessment instruments appropriate for these foci. In most cases, these scales are relatively new and have neither been used widely nor validated systematically. However, they have been found useful in certain clinical and experimental settings. These include the Civilian Mississippi PTSD Scale developed by John Fairbank and associates, an all-purpose self-report scale used following several natural disasters; the Crime-Related PTSD Scale (Based on the SCL-90) developed by Dean Kilpatrick and colleagues used with victims of criminal trauma; a scale to assess childhood trauma from adult patients developed by Judith Herman and Bessel van der Kolk; and the Child PTSD Reaction Index (with both a parent and child module) developed by Kathleen Nader and Robert Pynoos to assess the impact of trauma in children.
The above list is not meant to be complete, but rather a sampling of the variety of new diagnostic instruments that may assist clinicians as well as researchers working with different types of traumatized groups. Most of these scales have not been published but are generally available from the author(s) on request.
Biological approaches to diagnosis of PTSD are also receiving much attention. These were reviewed in The PTSD Research Quarterly (Summer 1990) and will only be outlined here. Psychophysiological paradigms, developed by Lawrence Kolb, Terry Keane, Roger Pitman and others complement more traditional assessment techniques. Blood pressure, pulse rate, skin conductance and other physiologic indices show excessive levels of arousal when an individual with PTSD is exposed to a stimulus reminiscent of his/her traumatic experience. For war-zone veterans, such a stimulus might be an audiotape of combat sounds, pictures of combat scenes, or a videotaped excerpt from the movie, "Platoon."
Other biological procedures that appear promising in diagnosing PTSD include: a) the measurement of neurohormones in 24 hour urinary samples; b) monitoring the sequential patterns of brain waves (sleep EEG); c) monitoring the acoustic startle eyeblink response; d) administering yohimbine, a drug which elicits panic attacks in patients with panic disorder; and e) measuring pain thresholds after exposing an individual to a stimulus reminiscent of the trauma. John Mason and colleagues at the National Center have shown that the pattern of urinary neurohormones seen in PTSD patients is abnormal and unique. The eyeblink monitoring procedure consists of a laboratory set-up in which the latency and intensity of the eyeblink response is measured following an auditory stimulus. Because diagnostic criteria for PTSD include insomnia and an exaggerated startle response, the eyeblink and sleep recording techniques are simply more precise ways to measure the same symptoms that are usually observed by most clinicians. Research by Dennis Charney and associates at the National Center shows that yohimbine can elicit PTSD flashbacks and panic attacks in a significant number of Vietnam theater veterans with PTSD. Finally, Roger Pitman, Bessel van der Kolk and associates have shown that higher pain thresholds among PTSD patients following exposure to a trauma-related stimulus seems to be due to increased activity of endogenous opioids, the body's naturally occurring painkillers.
Treatment and clinical outcome studies have begun to appear in the literature. Most published reports concern either behavioral or pharmacological interventions. Pat Boudewyns' and Terry Keane's groups have independently demonstrated the efficacy of behavioral approaches using direct therapeutic exposure. Although many reports have appeared regarding clinical trials of several different families of drugs, only five of these reports describe well controlled studies. In general, most investigators have had favorable results with antidepressant medications (tricyclic antidepressants and monoamine oxidase inhibitors), but there have also been negative reports. Other drugs of interest have not been tested in controlled (doubleblind) clinical trials. These include fluoxetine (Prozac), carbamazepine (Tegretol) and propranolol (Inderal). An ambitious study by Brom and associates compared different treatments: trauma desensitization, hypnotherapy and psychodynamic therapy. Although positive results were seen following all three therapeutic approaches, a different pattern of improvement was seen for each treatment. Clearly more research is needed to help clinicians select the most appropriate therapeutic strategies for their patients.
There is now ample evidence from research with war-zone veterans, traumatized children, victims of sexual assault and survivors of natural disasters indicating that the greatest risk factor for the later development of PTSD is the magnitude of exposure to the trauma itself. Different investigators have hypothesized, however, that other factors also influence the vulnerability of individuals to develop PTSD. This exciting area of research is just beginning. Variables proposed as possible risk factors for PTSD include: a) a history of prior traumatization, especially during childhood; b) personal and/or family history of psychiatric illness; c) negative life events shortly before exposure to the trauma, d) social support; e) educational level; and f) genetic factors. It should be noted that these are only hypotheses about risk factors and should not be considered as conclusive at this time.
Another important question receiving little attention to date, concerns the possibility that PTSD has adverse effects on physical as well as mental health status. Three recent studies support this possibility. Edward Blanchard and associates reviewed the current psychophysiological and cardiovascular literature and concluded that PTSD patients consistently exhibit higher resting blood pressures than non-PTSD controls.. Arieh Shalev and colleagues observed impaired cardiovascular function among Israeli combat veterans with PTSD. Finally, Abla Sibai and associates found that the severity of arteriosclerotic heart disease among hospitalized patients in Beirut, Lebanon varied directly with exposure to violent episodes during the Lebanese Civil War.
There are several reasons that each of these various areas of research are important. Basic research on PTSD contributes to our knowledge of PTSD as a diagnostic entity, in terms of signs, symptoms, and course. These efforts will enhance our understanding of traumatization as a process as well as an outcome. Finally, and perhaps most importantly, research on PTSD promotes efficacious treatment for our clients and patients whose lives have been acutely and often chronically disturbed.
Before closing I'd like to mention some key issues that need to be addressed systematically in future investigations. Biological and treatment outcome research has been largely restricted to war-zone veterans. Clearly, similar types of studies need to be conducted on survivors of other types of trauma such as natural disasters, sexual assault, industrial accidents, etc. An obvious direction for future trauma studies, therefore , will be to clarify whether the subjective, behavioral and biological response to different types of trauma is the same as the response to war-zone trauma. Other issues include whether there are gender-specific factors that may promote a different trauma response in women as compared with men;. how PTSD is expressed differently in people from different cultures and nationalities; and whether there are other psychiatric syndromes resulting from traumatic exposure that may have a unique cluster of symptoms that can be distinguished from PTSD. Proposed candidates for other trauma syndromes include multiple personality disorder, borderline personality disorder and what some people used to call victimization disorder and now called DESNOS (disorders of extreme stress not otherwise specified). The examination of these issues have major implications for diagnostic assessment and treatment strategies. I believe that the next ten years will prove extremely exciting as we begin to sort out these and other important aspects of PTSD.
Dr. Friedman is the Executive Director of the National Center for PTSD. His usual column will not be featured this month.
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