I believe many cases of posttraumatic stress disorder (PTSD) can be prevented in combat troops through proper education. According to the American Psychiatric Association, PTSD is a severe anxiety reaction to a traumatic event, such as rape or war, in which individuals repeatedly relive the event, avoid stimuli associated with the trauma, and experience symptoms such as difficulty sleeping and irritability.1 Typically the symptoms develop shortly after the event, but also could take years to develop. The duration for symptoms is at least 1 month for this diagnosis. Symptoms include reexperiencing the trauma through nightmares, obsessive thoughts, and flashbacks. There is an avoidance component as well, where the individual avoids situations, people, and/or objects that remind him of the traumatic event. For many people there is increased general anxiety, possibly with a heightened startle response. According to D. Grossman, for many people diagnosed with PTSD, it is like being told they have cancer; they assume it is fatal.2 PTSD is more like being overweight.3 Some people are just a couple of pounds overweight and they can use self-aid to get their weight under control. Other people are 20 to 30 pounds overweight and will need buddy aid and/or professional assistance. But full-blown PTSD is like being 50 to 100 pounds overweight, and without professional assistance they will likely have much trouble surviving. Almost all combat troops will have some form of PTSD or combat stress after continuous combat, but most of them will be fine.
Precombat education in the form of lectures about the psychological and physiological effects of combat will prevent much combat stress because it teaches warriors about the phenomena found in combat. Much self-induced stress comes from a lack of education, such as people being raised hearing “thou shall not kill.”4 According to The Marines’ Bible the commandment should have been written, “thou shall not murder.”5 The point is there is a big difference between murder, which is unjustifiable killing, and justifiably killing an enemy combatant. When someone is trying to kill you or those you are sworn to protect, you are justified in killing them first.
My hypothesis, although I have found no supporting empirical evidence, is that I am absolutely sure that educating troops before combat about the sensations they will encounter will eliminate some PTSD causes and reduce the effects of many others. This education must also be reinforced during and after combat to be truly effective. I do not believe that PTSD can be totally eliminated for all combat troops. The initial phases of my recommended research can be easily accomplished within the military community, but research may lose some subjects as the years go on due to death or a lack of willingness to continue participating. My hypothesis is feasible to study because there is a lack of long-term research information on combat troops who suffer from PTSD. I chose a longitudinal study because I have learned through my education in psychology and research that a longitudinal study can be very valuable for future generations—in this case future combat troops. My research design, a longitudinal study with randomly selected control and test groups, will, due to its nature, ensure ambiguity is not a concern. I will be using the Minnesota Multiphasic Personality Inventory (MMPI), which is the most often used psychological test for military PTSD clients. My research design is feasible due to its simplicity. This research does have some ethical concerns that will be addressed later in this article. This research may even be groundbreaking due to it being longitudinal and because it is using 21st century combat troops. My proposed research is justifiable in that it may help many combat troops in the future with the prevention of PTSD rather than the treatment of the disorder after troops are already being affected by it.
According to Davidson and Foa the classification of disease can be based on symptoms, anatomical change, pathogenesis, or etiology, the four entities representing a hierarchical sequence of increasing desirability.6 PTSD is based on the etiological occurrence of a traumatic event, but it also sits within the nonetiologically based group of anxiety disorders. With respect to PTSD, there are data that seem to support an etiological classification. First, epidemiological data reveal that after a volcanic eruption in a community, only 3 out of 12 psychiatric disorders increased in the year that followed. Given that general anxiety disorder (GAD) has a significant overlap with PTSD, findings that both disorders are increasing are not surprising. Single episode depression was often noted to contain many symptoms of PTSD and may perhaps be regarded as a form of posttraumatic depression. It is noteworthy that persons who demonstrated vulnerability for depression as evident from previous episodes did not show further increase in depressive symptoms after the trauma. Support for etiological classification also comes from psycho-physiological studies of PTSD. Physiological reactivity occurred on presentation of trauma-related stimuli to combat veterans who had PTSD; however, this type of reactivity was not found when combat stimuli were presented to combat veterans who did not have PTSD but had other anxiety disorders. In other words, PTSD is not just a general stress response in anxiety prone people. Inspection of the preservice records of Vietnam veterans strongly suggested that physiological changes did result from combat trauma since pre-Vietnam pulse rates were not higher in those veterans who later developed PTSD than in the controls. Thus, it may well be that the tonic (enduring) sympathetic hyperactivity that characterizes combat veteran patients with PTSD was absent in those warriors before the trauma.
Descriptive and empirical research strongly supports the view that PTSD contains three symptom clusters. The first is the intrusive symptoms (Criterion B), which are intermittent, phasic, and specific to PTSD. The avoidant and numbing cluster (Criterion C) comprises phasic avoidance of trauma reminders, which again are specifically related to PTSD but are also found in phobias. A second component of the avoidant criteria comprises enduring loss of interest, disinvolvement with others, and a foreshortened sense of the future. Those are not peculiar to PTSD and are found in other disorders, such as depression. Third, hyperarousal symptoms (Criterion D) include phasic and tonic components. Most of these are not specific to PTSD. Resnick, Kilpatrick, Dansky, Saunders, and Best researched the prevalence of crime and noncrime civilian traumatic events.7 Lifetime PTSD and PTSD in the past 6 months were assessed in a sample of participants. Lifetime exposure to any type of traumatic event was 69 percent whereas exposure to crimes that included sexual or aggravated assault or homicide of a close relative or friend occurred among 36 percent. Overall sample prevalence of PTSD was 12.3 percent lifetime and 4.6 percent within the past 6 months. The rate of PTSD was significantly higher among crime versus noncrime victims (25.8 percent versus 9.4 percent). History of incidents that included direct threat to life or receipts of injury were risk factors for PTSD. Findings are compared with data from other epidemiological studies.
According to Comer the behavior model explains behaviorism as deterministic, in that our actions are determined largely by our life experiences.8 The emphasis is on observable behavior and environmental factors and on how behavior is acquired (learned) and maintained over time. Behaviorists explain abnormal functioning by classical conditioning. Their aim is to identify the behaviors that are causing problems and replace them with more appropriate ones and may use classical conditioning, operant conditioning, or modeling approaches. This model has been and continues to be a powerful force in the field and is rooted in empiricism and therefore has significant support. In contrast, some people criticize behaviorism for being oversimplified and unrealistic and point out that it downplays the role of cognition. The cognitive model seeks to account for behavior by studying the ways in which the person attends to, interprets, and uses available information. Clinicians ask questions that challenge assumptions, attitudes, and thoughts; are concerned with internal processes; and are present focused. “Maladaptive thinking causes maladaptive behavior” is how a cognitive theorist explains abnormal functioning. The focus of cognitive therapy is on identifying maladaptive thoughts and teaching new ways of thinking to prevent maladaptive behavior. The goal is to help clients recognize and restructure their thinking. The cognitive model has been criticized for having a singular, narrow focus on overemphasis on the present at the exclusion of the past. Critics argue that a causal relationship and the precise role of cognition on abnormality are hard to determine. The cognitive model, because of the tendency for clients to have faulty cognitions which lead to their maladaptive behaviors, best explains the etiology of PTSD.
Although there are many very high-quality personality tests used by psychologists, the MMPI and its updated versions have been used for over 70 years. The MMPI series is very useful for many types of psychological issues, and the MMPI–2 is the most used test by military psychologists when attempting to detect PTSD symptoms. Although the MMPI series has its critics, it remains one the most widely used types of personality tests available. The MMPI and its offspring have been found to be reliable and valid. According to Butcher, Dahlstrom, Graham, Tellegen, and Kaemmer, the MMPI–2 was published in 1989.9 Today it is the most frequently used clinical testing instrument and is one of the most researched psychological tests in existence. The MMPI–2 is not a perfect test, but it remains a valuable tool in the diagnosis and treatment of mental illnesses. According to Butcher and Williams, mental health professionals who assess and diagnose mental illnesses most commonly use the MMPI–2, it is ideal for adults and is presently used to detect PTSD and traumatic brain injuries (TBIs) in U.S. Marines by naval neuropsychologists.10
According to Bury and Bagby, the MMPI–2 is especially useful in the detection of feigned uncoached and coached PTSD.11 According to Wetter and Deitch, the MMPI–2 is extremely useful in the detection and identification of the ability of persons faking PTSD or closed-head injury (CHI, now known as TBI) to respond consistently across serial testing.12 Results showed that individuals faking PTSD obtained 2-week test/retest reliability scores comparable to individuals completing the MMPI–2 with standard instructions; individuals faking CHI/TBI obtained reliability coefficients significantly lower than individuals faking PTSD. According to Kaplan and Saccuzzo, the MMPI–2 should be administered, scored, and interpreted by a professional, preferably a clinical psychologist or psychiatrist, who has received specific training in MMPI–2 use.13
To acquire the results of the MMPI–2, the true/false items are organized after scoring into validity, clinical, and content scales. After scoring, the configuration of the test taker’s scale scores is marked on a profile form that contrasts each client’s responses to results obtained by the representative community comparison group. The clinician is able to compare a respondent’s choices to those of a large normative comparison group as well as to the results derived from earlier MMPI–2 studies. The clinician forms inferences about the client by analyzing his response patterns on the validity, clinical, and content scales using published guidebooks to the MMPI–2. Special supplementary scale scores are often incorporated into the examiner’s interpretation of the test results. Commonly used supplementary scales include the MacAndrews Revised Alcoholism Scale, the Addiction Potential Scale, and the Anxiety Scale. According to Kaplan and Saccuzzo, the types of validity evidence include content validity, criterion validity, and construct validity evidence.14 The advantage of the MMPI–2 is that it is the most used and most researched psychological test in the world. A particular strength of the MMPI–2 is its measures of validity.
One disadvantage of the MMPI–2 is its length. At 567 items it is the longest of all commonly used personality inventories. The MMPI–2 was developed with psychiatric patients not medical patients. Although a great deal of research has been done with the MMPI–2 in various medical conditions, when the MMPI is administered to persons with medical disorders, interpretation becomes more difficult. The experienced examiner is able to make corrections for this, but this difficulty with interpretation has been seen by some as a weakness.15 Although the MMPI–2 may be administered by trained clerical staff or by computer, for best results, the examiner should meet the test taker before giving the test in order to establish the context and reassure the client.16 Most important, the test responses should be interpreted only by a qualified mental health professional with postgraduate education in psychological assessment and specialized training in the use of the MMPI–2.
Remember, the MMPI–2 is just a tool to help psychologists with the assessment of possible psychological problems. For instance, Engdahl, Eberly, and Blake found that the MMPI–2 could be useful in the identification of combat veterans suffering from PTSD.17 Once a possible PTSD victim is identified, psychologists may use the MMPI–2 to ensure they are not feigning the disorder. According to Efendov, Sellbom, and Bagby, the MMPI–2 is valid in the detection of feigned PTSD.18 I have spent over 7 years assisting psychologists, military commanders, and combat veterans with issues associated with PTSD. Although I spend some time assisting them after the fact, my real goal is the prevention of PTSD through education. I wrote the book, Surviving Combat: Mentally and physically, which is the basis of my 4-hour precombat seminars.19
Ethics and Conduct of Research
The main ethical concern is that some troops will not be given the psychological training that could help them prevent PTSD, but this is already happening. Some unit commanders ensure their warriors are psychologically trained while others do not. Ethics are always a concern for clinicians. Fear of potentially harming clients by attaching diagnostic labels has made many professionals cautious about using them with their clients. There are also ethical concerns when utilizing the Diagnostic and Statistical Manual of Mental Disorders (DSM–IV), such as the accurate assessment of clients. According to Davidson and Foa, clinicians should take certain items into consideration when assessing a client. These items include the careful examination of information provided by the client, the client’s willingness to share information, and that information’s accuracy. Each are essential to ensure the depth and application of what is presented, as well as the subsequent motivation and behavioral changes that will be needed in the intervention process.20 Special attention should be given not only to what the client is saying but also the context in which this information is revealed. The temptation to let the diagnostic impression or intervention approach guide the problem, rather than allowing the problem to guide the approach, should always be resisted. Clinicians should never lose sight of the ultimate purpose of the assessment process, which is to complete an assessment that will help to establish a concrete plan that can best address a client’s needs. In ethical and moral professional practice, it is essential that individual influences do not directly affect the assessment process. Therefore the clinician’s values, beliefs, and practices that can influence treatment outcomes must be clearly identified from the onset of treatment. Issues surrounding culture and race should be addressed openly in the assessment phase to ensure that the most open and receptive environment is created. For example, the clinician needs to be aware of his own cultural limitations, be open to cultural differences, and recognize the integrity and the uniqueness of the client, while utilizing the client’s own learning style, including his own resources and supports.
To mitigate crossing ethical lines, we will use the American Psychological Association (APA) Ethics Code as our reference.21 The fact that an ethical standard does not specifically address a given conduct does not mean that it is necessarily ethical or unethical. This ethics code applies only to researcher activities that are part of their scientific roles as psychologists. Researchers who delegate work to employees, supervisees, or other researchers or who use the services of others, such as interpreters, will take reasonable steps to (1) avoid delegating such work to persons who have a multiple relationship with those being served that would likely lead to exploitation or loss of objectivity; (2) authorize only those responsibilities that such persons can be expected to perform competently on the basis of their education, training, or experience, either independently or with the level of supervision being provided; and (3) see that such persons perform these services competently. When indicated and professionally appropriate, researchers will cooperate with other professionals in order to serve their clients effectively and appropriately. Researchers must obtain the informed consent of the individuals using language that is reasonably understandable to that person or persons except when law or governmental regulation mandates conducting such activities without consent or as otherwise provided in the APA Ethics Code. Researchers will appropriately document written or oral consent, permission, and assent. When obtaining informed consent, researchers will inform all participants about the purpose of the study, expected duration, and procedures; their right to decline to participate and to withdraw from the research once participation has begun; the foreseeable consequences of declining or withdrawing; reasonably foreseeable factors that may be expected to influence their willingness to participate, such as potential risks, discomfort, or adverse effects; any prospective research benefits; limits of confidentiality; incentives for participation; and whom to contact for questions about the research and research participants’ rights. They provide opportunity for the prospective participants to ask questions and receive answers. Researchers have a primary obligation and take reasonable precautions to protect confidential information obtained through or stored in any medium, recognizing that the extent and limits of confidentiality may be regulated by law or established by institutional rules or professional or scientific relationship. Researchers discuss confidential information obtained in their work only for appropriate scientific or professional purposes and only with persons clearly concerned with such matters.
Researchers will not disclose in their writings, lectures, or other public media, confidential, personally identifiable information concerning their clients/patients, students, research participants, organizational clients, or other recipients of their services that they obtained during the course of their work, unless they take reasonable steps to disguise the person or organization, the person or organization has consented in writing, or there is legal authorization for doing so. When researchers provide public advice or comment via print, Internet, or other electronic transmission, they take precautions to ensure that statements are based on their professional knowledge, training, or experience in accord with appropriate psychological literature and practice; are otherwise consistent with this ethics code; and do not indicate that a professional relationship has been established with the recipient.
Periodically researchers may release test data, such as when we reach certain milestones (e.g., 5- and 20-year marks). If researchers discover significant errors in their published data, they will take reasonable steps to correct such errors in a correction, retraction, erratum, or other appropriate publication means. The term “test data” refers to raw and scaled scores, participant’s responses to test questions, and researchers’ notes concerning participant statements and behavior during testing. Those portions of test materials that include participant responses are included in the definition of test data. Researchers may, at times, refrain from releasing test data to protect a participant or others from substantial harm or misuse or misrepresentation of the data or the test, recognizing that in many instances law regulates release of confidential information under these circumstances. Researchers must maintain security of study information. The term “study information” refers to manuals, instruments, protocols, and test questions or stimuli and does not include test data. Researchers will make reasonable efforts to maintain the integrity and security of test materials and other assessment techniques consistent with law and contractual obligations, and in a manner that permits adherence to this ethics code.
According to Kaplan and Saccuzzo, the longitudinal method is a special kind of observation.22 Its task is to determine causes of inward individual changes that happen to one person, different individuals, or various groups of people. This research method is considered to be the ideal one for developmental psychology that can be defined as a science that studies changes that happen in a human’s behavior depending on his age. According to E.R. Babbie, the ethics of social research apply more to the methods employed, and political issues are more concerned with the substance and use of research.23 There are no formal codes of acceptable political conduct comparable to the codes of ethical conduct that many professional associations have established.
A political concern for me is that some opponents may politicize this study, stating that we did not train all warriors with precombat psychological training. There is presently no standard for psychological training for warriors before combat; therefore, I believe this study is justified. If my theory is correct, that warriors need psychological training before combat, there may very well be some major fallout for our military and government. American citizens will likely say, “No kidding. Training the warriors to not get PTSD makes sense. Why did we not do this years ago?” I can predict that families of our control group may get very upset knowing we could have helped their loved ones avoid PTSD.
Another political concern is the “informed consent” used in the military. Many people may claim senior leadership used undue influence, which means there was no opportunity for the troops to say “no.” Also, attrition is a major concern. Unfortunately, some of these warriors will die in combat, some will commit suicide when they return, and others will die of a plethora of causes before the study is complete, while some of them will choose not to participate through the end of the study. Sheer numbers will be helpful. An infantry battalion is about 1,000 men.
Design and Procedures
I propose that a longitudinal research study of present-day troops will answer the question, “Can PTSD be prevented in combat troops through proper education?” To answer this question, new troops will be given the MMPI–2 before entering combat. The troops will be randomly selected for the test group and control group. One infantry battalion will be given extensive precombat psychological education while another infantry battalion, the control group, will receive no more than the mandatory predeployment psychological training. It is imperative that the battalions be sent into the same area for combat operations at the same time in an attempt to ensure they have similar experiences. I originally considered using companies within battalions for the experimental and control groups but was advised that they would be too close to each other, possibly leading to bleed over of the experimental group into the control group.
This research can be easily conducted and is relatively cheap. A U.S. Navy psychologist will administer the MMPI–2 to all troops before and after combat and periodically throughout their lives. Due to the nature of my proposed study I will not be using a scale that is normally seen in these studies. The psychologists will analyze the MMPI–2 before the participants go to combat, again after they return, and periodically over the years of the study. The schedule for testing is as follows:
3 to 6 months before deployment.
3 to 6 months after deployment.
2 years after deployment.
5 years after deployment.
10 years after deployment.
20 years after deployment.
Although this study would require authorization from Headquarters Marine Corps (HQMC), the formal gatekeepers would be the U.S. Navy psychology department at Walter Reed National Military Medical Center (WRNMMC). They justify and approve all psychological studies and make their recommendations to HQMC. When and if this study is approved, the psychology department at WRNMMC would have to manage the entire study. Due to the sensitivity of the information gathered, there would be no interaction with informal gatekeepers. There is no way to determine budget information for this study. However, the following concern has been identified: travel costs for members who are discharged from the military. All other costs are already covered due to this being a military-run study.
Although the battalion will be from Camp Lejeune, the data will be sent to WRNMMC for analysis. A database will be created and maintained by the psychology department at WRNMMC. The MMPI–2 will be administered at Camp Lejeune and the data sent via secure networks to WRNMMC. As the years go on, the MMPI–2 will be administered at various military bases and Veterans Administration locations and again sent to WRNMMC. This is due to the fact that many participants will be transferred to other bases or discharged from the Marine Corps. All data will be secured on the military’s secret computers and networks as is common practice with sensitive information. The psychology department is trained to analyze and interpret all MMPI–2 information. Due to the nature of the MMPI–2 there is little chance of any bias issues.
All data collection will be done on military members in the United States; therefore, there will be no field evaluations conducted. The harm principle is an issue for this study because if the control group has considerably more members diagnosed with PTSD, we could have helped with extensive psychological training. But as I have already stated, it is up to commanders how much psychological training their warriors receive; therefore, this is an acceptable possibility. The WRNMMC psychology department will develop a method of analyzing and interpreting the data; the MMPI–2 is normally used for individuals, not groups; therefore, Bethesda will have to determine the best method of developing an appropriate scale for determining what the data is telling us. Success of this study will be based on the percentage of participants from each group who are diagnosed or not diagnosed with PTSD under like combat conditions.
My primary audience is military personnel with a secondary audience being Federal and local law enforcement personnel. This study could also possibly be useful to civilians. Although this is a longitudinal study, data will be published at each instance of collection. (See the testing schedule above.) The final data will be published 20 years after the combat deployments. Findings will be submitted to the Navy Bureau of Medicine and Surgery (BUMED), the headquarters command for Navy Medicine and under the leadership of the Navy Surgeon General. Due to privacy issues and the sensitivity of this study, BUMED will have total control of the release of data, either to the public or not to the public.
I foresee no abuses of the study’s data, with the exception of some politicians pointing fingers at each other in an attempt to gain a political advantage over their opponents. Results of the study (individual and group) will be presented to the actual participants through BUMED and the Veterans Administration. This is the only authorized method of data distribution as mandated by BUMED. Due to BUMED regulations for medical studies, all applications for release of these findings will be made through BUMED.
If my hypothesis is correct, I believe it will change the way combat troops are trained. For instance, commanders will not have as much latitude as they presently do when it comes to precombat training. Instead of concentrating solely on destroying the enemy and his will to fight, we will start training our warriors to survive the psychological effects of combat.
We could go a generation without teachers. We would have to play catch up later, but we would survive. We could go a generation without doctors. We would have to play catch up later, but we would survive. But if we went a generation without warriors we would be both damned and doomed. The warrior moves toward the sound of the gun while everyone else is running away. We must nurture the warriors’ spirit. We must train to kill, have the willingness to kill when needed (not want to kill, but be willing to kill), and we must be willing to face the consequences of killing. Combat is of such emotional intensity that strange elations can come from the act of killing. Opponents pit themselves against each other with the certain knowledge that one will be vanquished and one will be victorious. All want to live but one can live only by the death of the other. Only by killing is life sustained. This is the way of war. And it is amid this topsy-turvy world of war, in which violence provides a chance to live for another day, that the combatant must be on guard to preserve his own morality.
>Editor’s Note: A summary of this article was published in the U.S. Naval Institute’s Proceedings magazine on July 2011, pp.76-77.
1. APA, Diagnostic and Statistical Manual of Mental Disorders DSM–IV–TR, Fourth Edition, Washington, DC, 2000.
2. Grossman, D., On Combat: The Psychology and Physiology of Deadly Conflict in War and Peace, PPCT Research Publications, New York, 2004.
3. Devaney, D.K., Surviving Combat: Mentally and Physically, Third Edition, Twentynine Palms, 2007.
4. New King James Version Bible, Thomas Nelson, Inc., Nashville, TN, 1982.
5. The Marines’ Bible, Holman Bible Publishers, Nashville, TN, 2003.
7. Resnick, H.S., D.G. Kilpatrick, B.S. Dansky, B.E. Saunders, and C.L. Best, “Prevalence of Civilian Trauma and Posttraumatic Stress Disorder in a Representative National Sample of Women,” Journal of Consulting and Clinical Psychology, APA, Washington, DC, December 1993, pp. 984–991. Accessed at Park University secure website for student use only.
8. Comer, R.J., Abnormal Psychology, Seventh Edition, Worth Publishers, New York, 2010.
9. Butcher, J.N., W.G. Dahlstrom, J.R. Graham, A.M. Tellegen, and B. Kaemmer, Minnesota Multiphasic Personality Inventory–2 (MMPI–2): Manual for Administration and Scoring, University of Minnesota Press, Minneapolis, MN, 1989. See also Comer.
10. Butcher, J.N. and C.L. Williams, Essentials of MMPI–2 and MMPI—An Interpretation, Revised, University of Minnesota Press, Minneapolis, MN, 1999.
11. Bury, A.S. and R.M. Bagby, “The Detection of Feigned Uncoached and Coached Posttraumatic Stress Disorder With the MMPI–2 in a Sample of Workplace Accident Victims,” Psychological Assessment: A Journal of Consulting and Clinical Psychology, APA, Washington, DC, December 2002, pp. 472–484. Accessed at Park University secure website for student use only.
12. Wetter, M.W., and S.E. Deitch, “Faking Specific Disorders and Temporal Response Consistency on the MMPI–2,” Psychological Assessment, 1996, pp. 39–47.
13. Kaplan, R.M., and D.P. Saccuzzo, Psychological Testing: Principles, Applications, and Issues, Seventh Edition, Wadsworth Publishing, New York, 2009.
15. Health Psychology Associates, Psychological Tests for Persons With Medical Disorders, APA, Washington, DC, 1997. Accessed at Park University secure website for student use only.
16. Encyclopedia of Medical Disorders. Available online at www.minddisorders.com, accessed at Park University secure website for student use only.
17. Engdahl, B.E., J.D. Blake, and R.E. Eberly, “Assessment of Posttraumatic Stress Disorder in World War II Veterans,” Psychological Assessment, APA, Washington, DC, 1996, pp. 445–449. Accessed at Park University secure website for student use only.
18. Efendov, A.A., M. Sellbom, and R.M. Bagby, “The Utility and Comparative Incremental Validity of the MMPI–2 and Trauma Symptom Inventory Validity Scales in the Detection of Feigned PTSD,” Psychological Assessment, APA, Washington, DC, 2008, pp. 317–326, and M.J. Gray, E.E. Bolton, and B.T. Litz, “A Longitudinal Analysis of PTSD Symptom Course: Delayed-Onset PTSD in Somalia Peacekeepers,” Journal of Consulting and Clinical Psychology, APA, Washington, DC, October 2004, pp. 909–913. See Engdahl, et al. Accessed at Park University secure website for student use only.
20. Davidson and Foa.
21. APA, Ethics Code, Washington, DC, 2003.
22. Kaplan and Saccuzzo.
23. Babbie, E.R., The Practice of Social Research, Twelfth Edition, Wadsworth Publishing, New York, 2009.