One head-to-head comparison of symptom criteria between the DSM-5 version of the PTSD Checklist (PCL-5) and the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) version (PCL-S) among 1,822 infantry soldiers showed high discordance. 11 Of soldiers who met DSM-IV symptom criteria, 30% did not meet DSM-5 criteria, and an equivalent number only met criteria under DSM-5. This was one of the only studies that maintained independence of the 2 clinical scales (rather than adding DSM-5 symptoms to an existing DSM-IV scale). This study also controlled for the order in which the 2 scales were presented on the survey, which was found to be critically important. 11 Furthermore, there was no difference in the overlap with comorbid conditions (eg, major depression, generalized anxiety, alcohol misuse) and no difference in level of functional impairment, suggesting that the new definition has no greater specificity or clinical utility than does the original.
The diagnostic discordance between DSM-IV and DSM-5 was mostly accounted for by the redefinition of C criterion (avoidance) in DSM-5. In an editorial accompanying the comparison study, Alexander C. McFarlane, MD, AO, raised concerns about this decision and the decision to effectively remove the important symptom of numbing of emotions. 12 These changes could disenfranchise service members and veterans who learn to override avoidant behaviors through training and who often cope with their reactivity through emotional numbing. 12 These various concerns, as well as years of experience
with the original definition and importance of aligning trauma-focused treatment with the most appropriate diagnosis, suggest that clinicians have reasonable justification for continuing to assign the PTSD diagnosis for veterans who meet full criteria for PTSD under the previous DSM-IV definition.
Another clinical concern of the revision is the potential problem with selecting a diagnosis for subthreshold PTSD. Subthreshold PTSD can be broadly defined as PTSD symptoms that do not meet full criteria for diagnosis but impair functioning sufficiently for traumafocused treatment to be indicated. DSM-5 recommends use of adjustment disorder in this circumstance. 10 However, in military populations, this definition carries a pejorative connotation (weakness or failure to adapt) and can also lead to administrative separation without medical benefits if the condition has lasted < 6 months. 13 Chronic
adjustment disorder is medically compensable under VA and DoD regulations but suffers from poorly defined clinical criteria, in addition to the pejorative connotation. (Chronic adjustment disorder was inadvertently left out of the print version of DSM-5 but corrected online.)
As a result of these concerns, the VA National Center for PTSD has recommended that clinicians use ICD-9 code 309.89 (“other specified trauma- and stressor-related disorder” in DSM-5) instead of adjustment disorder for subthreshold PTSD. 14 However, current DoD electronic medical record systems map this code to even more pejorative labels (eg, adjustment disorder with aggression, antisocial behavior, or destructiveness). Thus, until the
VA and DoD adopt ICD-10 coding, which is expected to occur within the next year, clinicians will probably have to continue to use ICD-9 code 300.00 (“unspecified anxiety disorder” or “anxiety disorder not otherwise specified”) for clinically significant subthreshold PTSD.