Nostalgia or Shell Shock? Assessing PTSD Is a Challenge by Any Name


Irritable heart.

Shell shock.

No, this isn’t a word-association game. These are among the many terms applied over the years to the highly amorphous condition we now call post-traumatic stress disorder. While people have experienced shocking, scary, and dangerous events since the dawn of mankind, the study of the cause and treatment of PTSD is a relatively recent pursuit.

Even when the American Psychiatric Association formally recognized the condition in 1980, the subject got a skeptical reception from many medical professionals.

A lot has changed since 1980. U.S. troops have been fighting wars continuously for almost 17 years, and the Veterans Affairs Department estimates that between 11 and 20 percent of the men and women engaged in these conflicts suffer from PTSD. More than 3 million cases, military and civilian, are diagnosed in the U.S. each year, and it’s estimated that one in 11 Americans will experience the condition at some time in their lives.

But what is PTSD, really? Treatment depends on effective diagnosis, and diagnosis on uniform methods of identifying and assessing a condition that has diverse and far-reaching symptoms.

“Every man has his breaking point”
In the 1600s, Swiss military physicians identified among soldiers a condition marked by disturbed sleep, heart palpitations, and anxiety. Oddly, at least by the standards of contemporary English, they called it nostalgia. During World War II, the U.S. Army adopted the saying, “Every man has his breaking point,” positing that more than 90 days of continuous combat could render any soldier a psychiatric casualty.

But what constitutes PTSD depends on whom you ask, and there’s long been debate over how broad or narrow a definition should be applied. The “gold standard” for assessing the condition according to many — including the folks at Veterans Affairs — is CAPS-5, the fifth iteration of the Clinician Administered PTSD Scale. This 30-item patient interview is based on the 2013 revision of the ASA’s Diagnostic and Statistical Manual of Mental Diseases, commonly known as DSM-5. CAPS-5 is used to:

  • Make current (i.e., based on events of the preceding month) PTSD diagnoses.
  • Make lifetime diagnoses.
  • Assess patient symptoms over the preceding week.

CAPS-5 assesses 20 symptoms groups in four clusters, taking a broader approach than its predecessor, CAPS-4, which evaluated patients according to 17 symptoms in three clusters. This more inclusive approach is at odds with another popular set of measurement criteria, the World Health Organization’s ICD-11 (International Classification of Disease, 11th Edition). WHO views the CAPS-5 criteria as encompassing many symptoms that are not core to PTSD and limits its view to six specific symptoms to avoid overlap with other disorders.

Complex and puzzling
Reasonable people often disagree, so for purposes of this discussion, we’ll focus CAPS-5, developed over three years to streamline administration and scoring of patient evaluations and render a system that was easier to learn, reduced variability among raters, and took less time to administer and score than its CAPS-4 predecessor.

A recurring challenge in assessing PTSD, according to the DSM guidance, is the large sets of symptom criteria — some of them inherently complex, ill-defined, or downright puzzling, even to trauma experts. They include psychogenic amnesia and flashbacks. Working with such conceptually difficult symptoms, researchers really need to understand PTSD to assess it accurately.

Patient self-rating is generally insufficient, as the symptomatic nuances and complexities are just too extreme and not well-understood even by trauma experts. Accurate assessments require highly structured interviews by a clinician who fully understands the conceptual basis of PTSD.

That’s just how CAPS-5 was designed: to conduct interviews in the way that an expert clinician would. The approach is heavily scripted to pose the right questions in the right sequence and to provide clear guidance for accurate scoring. It includes standard prompts and assessments of symptom frequency and intensity.

It’s a testament to the protocol’s architects that just about any rater given enough experience with CAPS-5 can become proficient in assessing PTSD-associated trauma.

Up-front training
Dr. Frank Weathers, a psychology professor at Auburn University, recently used CAPS-5 to assess an all-veteran population at the National Center for PTSD. “It worked really, really well,” Dr. Weathers said, citing “excellent test-retest and interrater reliability and really strong convergent and discriminant validity.”

Even the best tool is useful only in skilled hands, so Dr. Weathers emphasized the need for rater training. “You really need to invest in good training on the front end, and then some sort of a calibration recertification process,” he said. “Some studies put a lot of effort into that, some not so much. On the ones I’ve been involved in where they are doing interrater reliability over time and good quality control, we have seen very good maintenance of skills over the course of the study.”

You can learn more on PTSD by watching our webinar and for additional reading, have a look at these posts below.

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