Many types of civil and criminal court cases and litigation involve claims of Posttraumatic Stress Disorder. The diagnostic validity of these claims can impact directly upon the defense, plaintiff, or prosecutorial strategy, depending upon the nature of the case. It is important, therefore, for attorneys and others involved in the legal system to be able to assess the validity of PTSD evaluations and diagnoses. Although only an expert in PTSD can complete an in-depth review of a case and the diagnostic methodology, it is helpful if those conducting initial reviews know some basic facts about PTSD and what constitutes a sound diagnosis.

What is the critical component of a PTSD diagnosis?

One of the critical components of a PTSD diagnosis is that the individual must have been exposed to a traumatic event. This criterion is often called the "gate-keeper." That is, without it PTSD cannot exist. The DSM IV is very specific in defining this term. In order to qualify as a traumatic event (in this context), the event must meet two criteria:

• "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 oneself or others."
• "the person's response involved intense fear, helplessness and horror."

Therefore, traumatic stressors must involve some type of actual or threatened physical injury or assault. Ongoing poor treatment and verbal abuse by a boss, discrimination, or ongoing emotional abuse by a spouse, for example, are not qualifying traumatic stressors in this context. However, if there has also been some fear of actual serious physical injury or "threat to the physical integrity" of the individual claiming PTSD (a phrase most often applied to sexual assaults or threats of sexual assaults), then these situations qualify as traumatic stressors. It is important to note that the person does not have to have been the direct victim of the event; witnessing or being confronted with a traumatic stressor can also meet this criterion.

The existence of symptoms should not be used to establish the fact that an individual has been exposed to a traumatic stressor. For example, the fact that someone is experiencing insomnia and angry outbursts should not be used to establish that he or she has experienced a traumatic stressor. Independent corroboration of the occurrence of the traumatic stressor should be obtained when possible.

What are the symptoms of PTSD?

Another critical component of a PTSD diagnosis is that the person must have symptoms consistent with PTSD. Approximately 25% of individuals exposed to traumatic stressors go on to develop PTSD; most exposure to trauma does not result in PTSD. Therefore, evidence of exposure to such a stressor alone is not sufficient to establish a diagnosis of PTSD.

The DSM IV specifies the pattern of symptoms that must occur in order for an individual to be diagnosed with PTSD. There are three categories of PTSD symptoms: reexperiencing, avoidance/numbing, and increased arousal. PTSD can only be diagnosed if one symptom of reexperiencing, three symptoms of avoidance/numbing, and two symptoms of increased arousal are present (see the DSM IV for a complete list of the symptoms in each category). If a person has six symptoms, for example, but all are in the hyper-arousal category, the diagnostic criteria have not been met.

Reliable and valid psychometric instruments should be used to determine whether an individual meets the symptomatic criteria for PTSD. However, data from psychometric tests should never serve as a stand alone means for diagnosing PTSD. Rather, the psychometric measures should be used to supplement and substantiate findings gleaned from interview assessment and other sources of data. The Clinician Administered PTSD Scale and the PTSD Symptom Checklist are two widely used PTSD assessments that have been established as reliable and valid.

A particularly important consideration in the forensic assessment of PTSD is that the symptoms of the disorder are entirely self-reported, although some of the increased arousal symptoms (such as an exaggerated startle response) can be objectively observed. In cases where secondary gain is involved, which include most forensic cases, it is particularly important for tests of malingering to be administered in conjunction with the PTSD assessment. If measures of malingering are not used in the assessment, the individual's report of his or her own symptoms may be characterized as fabrication or exaggeration.

In addition, recent research has demonstrated that there are specific biological changes that can be measured in individuals with PTSD, such as increased heart rate and blood pressure upon exposure to cues reminiscent of the trauma. Psychophysiological data is particularly convincing evidence of the existence of PTSD as it eliminates the issue of self-reporting and addresses the possibility that the individual may be malingering for secondary gain. However, not all individuals with PTSD exhibit these changes so the absence of this type of data should not be considered conclusive evidence that PTSD does not exist.

What other factors are critical for a PTSD Diagnosis?

A third critical component of a PTSD diagnosis is that the person's level of functioning pre- and posttrauma must be significantly different. For example, someone who was irritable, could not sleep, had difficulty concentrating, and felt detached and estranged before a trauma, and who continued to exhibit these symptoms at the same level of intensity after the trauma, should not be diagnosed with PTSD. There needs to be evidence of a general decline in functioning. Changes often observed as a result of PTSD include a deterioration of work or school performance, changes in one's ability to meet routine responsibilities of self-care, a worsening of physical health, and changes in interpersonal relationships, leisure activities, and family role functioning. A self-reported change in the level of functioning should be corroborated either with objective records or through collateral information.

The fourth critical component of a PTSD diagnosis is related to the above issue of a change in the level of functioning. This is the requirement that symptoms "cause clinically significant distress or impairment in social, occupational, or other important levels of functioning." In forensic cases, it is important to obtain corroboration of this distress or impairment because of the potential for deliberate fabrication or exaggeration. Corroboration can be obtained either through a records review or through reports from collaterals.

In addition, the impairment in functioning should be linked to PTSD symptoms. For example, the fact that after a trauma an individual became irritable and argumentative at work supports a diagnosis of PTSD. However, the fact that an individual began stealing things from the worksite after a traumatic experience does not support a diagnosis of PTSD because stealing is not a symptom of PTSD. Remember, though, that other changes noted in this same individual may support the diagnosis.

Finally, the symptoms of PTSD must persist beyond thirty days. An individual who, after a trauma, experiences a full complement of PTSD symptoms for three weeks does not meet the diagnostic criteria. The DSM IV does describe this type of reaction, however, and qualifies it as Acute Stress Disorder.

Conclusion

Proper assessment of PTSD is complex, and in a forensic setting, it should include substantial attention to corroboration of self-reports through a records review and collateral information. The ability to evaluate these assessments can be very helpful for those involved in the legal system. PTSD evaluation will be particularly practical for those who want to conclusively and convincingly establish a PTSD diagnosis and for those who need to appraise the accuracy or veracity of a PTSD claim that seems dubious. By paying attention to the five areas mentioned above, one can make an initial assessment of the accuracy of a PTSD diagnosis. In addition, if all five of the above elements are attended to, counsel can convincingly present evidence that an individual indeed suffers from the disorder.