Posttraumatic Stress Disorder: Diagnosis and Assessment (2006)

The Department of Veterans Affairs (VA) posed a series of the specific questions to the Institute of Medicine. Below are the committee’s responses to the questions that focused on diagnosis and assessment of posttraumatic stress disorder (PTSD). Questions related to treatment or compensation will be considered in later reports.

1. What are the accepted diagnostic criteria for PTSD?

The accepted diagnostic criteria for PTSD are given in the fourth edition of the American Psychiatric Association’s (APA) Diagnostic and Statistical Manual of Mental Disorders, Text Revision (DSM-IV-TR, hereafter referred to as the DSM-IV) (APA 2000). Chapter 2 (Box 2.1) lists those diagnostic criteria. In addition to DSM-IV, the World Health Organization disease classification system, ICD-10 (the International Classification of Diseases, 10th edition), includes diagnostic criteria for PTSD. The ICD diagnostic criteria for PTSD are similar to those in DSM-IV but do not include the DSM-IV criterion A2 (that a response to a traumatic event involves intense fear, helplessness, or horror).

It should be noted that a person might not meet full criteria for the PTSD diagnosis and yet still be highly symptomatic and in need of treatment. PTSD symptoms might be mild to severe, and functioning might be influenced by other factors, such as comorbid conditions or social support. Severe symptoms might be disabling even in the absence of a full diagnosis.

DSM-IV diagnostic criteria for PTSD are used by VA’s compensation and pension program, as required by the Code of Federal Regulations (38 CFR 4.130). DSM-IV is also accepted and relied on by private health-insurance companies, Medicare, Medicaid, and the Social Security Administration.

2. What would an evidence-based criteria set for diagnosis of PTSD include?

The diagnostic criteria for PTSD in DSM-IV (Box 2.1) are evidence-based and are the criteria most widely used by US health professionals. The criteria were developed by an expert task force assembled by APA in accordance with the process described in the introductory section of DSM-IV. The expert task force reviewed the evidence from the published scientific literature, reanalyzed data where necessary, and evaluated evidence from studies examining how the diagnostic criteria operate in real-world settings. A record of the evidence used by each task force is compiled in the several volumes of the DSM-IV Sourcebook (APA 2000).

3. What constitutes a stressor?

A stressor is any agent, condition, event, or other stimulus that results in a stress response. A stress response consists of behavioral and physiologic reactions that can cause changes in the functioning of an organism. A traumatic stressor, according to DSM-IV, involves two criteria: (1) the person experiences, witnesses, or is confronted with an event(s) that involves actual or threatened death or serious injury or threat to the physical integrity of oneself or others; and (2) the person’s response involves intense fear, helplessness, or horror. Traumatic events during wartime, for example, might include serving in dangerous military roles, such as driving a truck at risk for encountering roadside bombs, patrolling the streets, and searching homes for enemy combatants, suicide attacks, sexual assaults or severe sexual harassment, physical assault, duties involving graves registration, accidents causing serious injuries or death, friendly fire, serving in medical units, killing or

injuring someone, seeing someone being killed, injured, or tortured, and being taken hostage.

4. How should stressful events be diagnosed and documented?

Health professionals with experience in diagnosing psychiatric disorders should rely on a confidential interview to elicit and document the patient’s recollection of events, the impact on the patient, and to determine whether symptoms are present. Health professionals should ask relevant questions to determine whether the patient’s report is consonant with the DSM-IV traumatic-stressor criteria (criterion A).

A number of instruments have been developed and are used, primarily in research settings, to document exposures to combat-related traumatic stressors. It is important to remember that each combat theater is different and therefore presents unique opportunities for traumatic exposures. Health professionals need to be familiar with the specific kinds of traumatic exposures that might be encountered in each theater.

In some clinical and research settings, it might be possible to obtain additional data concerning combat-related traumatic exposures, such as contemporaneous combat records and medical records of injuries. However, those records are not always reliable, complete, or available and might not accurately reflect a person’s experience and psychological reactions.

5. How can and should a patient document a stressful event?

The primary role of the patient is to respond to the best of his or her ability to the questions of the health professional to elicit information about the stressful event(s). It should be noted that after exposure to trauma, the patient might have difficulty in recalling or describing what occurred. Some patients might be able to provide additional sources of documentation, such as eye-witness accounts, unit reports, medical records, occupational records, and medals or honors.

6. What are the components of an evidence-based diagnosis of PTSD?

An evidence-based diagnosis of PTSD comprises six components, according to DSM-IV: (1) exposure to a traumatic event, (2) intrusive re-experiencing of the traumatic event, (3) avoidance and numbing symptoms that were not present before the trauma, (4) symptoms of hyperarousal not present before the trauma, (5) at least a 1-month duration of symptoms, and (6) associated clinically significant distress or impairment.

7. What would diagnostic criteria be, based on best evidence, either based on or apart from official standards?

All diagnostic criteria should be based on best evidence. The official diagnostic criteria for PTSD as listed in DSM-IV were based on the best evidence that was available in 1994 when it was published. As indicated in the introduction to the DSM-IV, “Most diagnoses now have an empirical literature or available data sets that are relevant to decisions regarding the revision of the diagnostic manual. The Task Force on DSM-IV and its Work Groups conducted a 3-stage empirical process that included: (1) comprehensive and systematic reviews of the public literature, (2) reanalyses of already-collected data sets, and (3) extensive issue-focused field trials” (APA 2000).

As new evidence becomes available, DSM will be revised as necessary to reflect that evidence as reviewed by its expert panel. A new task force on PTSD will be formed in preparation for the next edition of DSM, which is to be published in 2011.

8. What constitutes optimal evaluation of a patient for PTSD?

Optimally, a patient should be evaluated in a confidential setting in a face-to-face interview by a health professional experienced in diagnosing psychiatric disorders (for example, psychiatrists, psychologists, clinical social workers, and psychiatric nurses). The interview should elicit the patient’s symptoms, assess the history of potentially traumatic events, determine whether the patient meets the

DSM-IV criteria for PTSD (see Chapter 2, Box 2.1), determine the frequency and severity of symptoms and any associated disability, and assess the presence of comorbid psychiatric and medical conditions. Adequate time should be devoted to this assessment. Depending on the mental and physical health status of the veteran and on the experience and background of the health professional conducting the assessment, the diagnosis and assessment process will likely take at least an hour or could take many hours to complete.

A major problem in optimizing evaluation for PTSD is that many health professionals do not have the time or experience to assess psychiatric disorders adequately or might be reluctant to attribute a veteran’s symptoms to a psychiatric disorder. Furthermore, veterans with PTSD might not present to a mental-health professional, because they might not attribute their symptoms to a psychiatric disorder, they might feel that there is a stigma associated with psychiatric illnesses, they might have little or inadequate access to such professionals, or there might be other considerations, such as cost.

Health professionals should be aware that veterans, especially those who have served in war theaters, are at risk for the development of PTSD, but might present with physical or psychiatric complaints that are symptomatic of substance use disorder or other psychiatric conditions. Health professionals should ask all veterans about possible exposure to potentially traumatic events. Brief screening instruments for PTSD have been developed for use in primary-care settings and should be considered to identify patients who might benefit from further evaluation.

9. What neuropsychological evaluation or other testing should be included in an optimal evaluation of a patient for PTSD?

Neuropsychological testing is not part of a PTSD diagnostic evaluation. However, during the evaluation of a patient for PTSD, a health professional might identify problems, such as memory loss, attention deficits, or confusion, which might suggest the appropriateness of neuropsychologic testing.

10. What are useful biomarkers?

No biomarkers are clinically useful or specific in diagnosing PTSD, assessing the risk of developing it, or charting its progression. Many biomarkers, however, are under study and they support a biologic basis of PTSD. Potential biomarkers currently under study include increased concentrations of corticotropin-releasing factor in the cerebrospinal fluid; low cortisol concentrations in the blood; measures of hyperarousal; delayed habituation to loud noises; panic attacks and flashbacks when noradrenergic systems are activated; alterations of brain structures, such as hyperactivation of the amygdala and hypoactivation of the prefrontal cortex when the person remembers trauma; and sleep disturbances, including nightmares of traumatic events. Reduced volume of the hippocampus might also be correlated with the development of PTSD. Preliminary evidence suggests that genetic factors might play a predisposing or modulating role in the development of PTSD.

American Psychiatric Association. 2000. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Washington, DC: American Psychiatric Association.