A comparison of ICD-11 and DSM criteria for posttraumatic stress disorder in two national samples of US military veterans

Background: The proposed ICD-11 criteria for posttraumatic stress disorder (PTSD) differ substantially from the DSM-5. ICD-11 eliminated several PTSD symptoms thought to be nonspecific, with the goal of reducing psychiatric comorbidities. However, this change also results in a narrower PTSD definition that may fail to capture individuals with clinically significant PTSD. The purpose of the current study was to compare prevalence and psychiatric comorbidities of DSM (IV/5) and ICD-11 PTSD. Methods: We evaluated concordance between DSM (IV/5) and ICD-11 PTSD diagnoses in a web survey of two nationally representative samples of U.S. military veterans (ns = 3517 and 1484). Lifetime and past-month PTSD symptoms were assessed with the DSM-IV-based PTSD Checklist-Specific Stressor version and the DSM-5-based PTSD Checklist-5. Psychiatric comorbidities were assessed using MINI Neuropsychiatric Interview modules. Results: A significantly greater proportion of veterans met criteria for lifetime and past-month PTSD under DSM-IV/5 than under ICD-11. 21.8-35.9% of those who met criteria under DSM IV/5 did not meet under ICD-11, whereas only 2.4-7.1% of those who met under ICD-11 did not meet under DSM-IV/5. Psychiatric comorbidities did not significantly differ between DSM-IV/5 and ICD-11. Limitations: This study relied upon self-report measures of PTSD, distress/impairment, and psychiatric comorbidities. Conclusions: The proposed ICD-11 criteria identify fewer PTSD cases than DSM-IV/5 without reducing psychiatric comorbidities. Veterans with clinically significant PTSD symptoms may not meet ICD-11 PTSD criteria, possibly affecting eligibility for healthcare, disability, and other services. The ICD-11 criteria could be revised to capture more PTSD cases before ICD-11 is published in 2018.