Measuring the Long-term Impact of War-Zone Military Service Across Generations and Changing Posttraumatic Stress Disorder Definitions.

Abstract

The neuropsychiatric impact of World War I, World War II, and the Korean War was described in terms such as shell shock, neurasthenia, psychoneurosis, and battle fatigue. For the Vietnam generation, readjustment problems were initially attributed to alcohol or substance use, followed by growing acceptance of persistent stress responses or post-Vietnam syndrome. In 1979, the US Congress directed the Veterans Administration to establish Readjustment Counseling Centers (Vet Centers) to provide community-based counseling options for combat veterans. By 1980, consensus was reached on the first definition for posttraumatic stress disorder (PTSD). However, scientific and political debate raged as to whether PTSD was a legitimate disorder and Vietnam service a legitimate cause; members of Congress called for closure of Vet Centers. The Congressionally funded National Vietnam Veterans Readjustment Study (NVVRS) emerged from this landscape. Completed between 1984 and 1988, the NVVRS provided the first representative study using newly available structured diagnostic interviews based on DSM-III-R. The 17-symptom PTSD definition established by the DSM-III-R would remain largely unchanged for the next 25 years. The NVVRS researchers concluded that 30% of Vietnam veteransmet PTSD criteria during their lifetime, and 15% still had PTSD.1 Although the NVVRS did not end debate, it paved the way for countless future studies that characterized PTSD epidemiology and neurobiology, the debilitating comorbidities associatedwith this condition, and evidence-based treatment strategies, many of which were first tested in Vietnam veterans. A 2006 NVVRS reanalysis by Dohrenwend et al2 addressed lingering concerns that original estimates were inflated by inaccurate self-reports of war-zone stressors or lack of a criterion for functional impairment (added in 1994 to the PTSDdefinition inDSM-IV).Drawingonoriginal diagnostic interviews and verifiable military records, lifetime and current war-zone–attributedPTSDprevalenceswererevisedto19%and 9%, respectively, with documentation of a strong combat exposuredose-response.2 Althoughmore conservative, these estimates confirmed the considerable burden of PTSD. This issue of JAMA Psychiatry brings another remarkable chapter tounderstanding the impactof theVietnamWar—a report from the National Vietnam Veterans Longitudinal Study (NVVLS).3Thismethodologically superb follow-upof theoriginal NVVRS cohort offers a unique window into the psychiatric health of these veterans 40 years after the war’s end. No other studyhas achieved this quality of longitudinal information, and the sobering findings tell us asmuch about theVietnam generation as about the lifelong impact of combat service in general, relevant to all generations. Like the NVVRS, theNVVLS comes at a historicwatershed after 14 years ofwar in IraqandAfghanistanandshortly afterpublicationofDSM-5, the first substantial revision of the PTSD definition since DSM-III-R (including marked wording changes, restructuring, and additional symptoms). Themost importantNVVLS finding is confirmationof the chronic anddebilitating courseofwar-relatedPTSD.Using the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5), Marmar and colleagues3 found lifetime and currentwar-zone PTSDprevalencesof 17.0%and4.5%, respectively, inmaleveterans (15.2% and 6.1%, respectively, in female veterans). Although lower than the estimates by Dohrenwend et al,2 these figures likely do not reflect the full disease burden owing to potential psychometric concerns with the CAPS-5 (discussed below) and because nearly a quarter of the cohort died in the interim between the NVVRS and NVVLS (PTSD is strongly associated with mortality). The full disease burden may be best represented by the definition that incorporates subthreshold PTSD, which the NVVLS researchers brilliantly measured using a stringent definition consistent with the need for treatment and which effectively encompasses previous (DSM-IV) criteria.3 This measurement raised the lifetime and current CAPS-5 estimates to 26.2% and 10.8%, respectively, in male theater veterans (25.7% and 8.7%, respectively, in female theater veterans). For additional confirmation, the NVVLS used an appended version of the PTSD Checklist for DSM-IV (PCL), scored using DSM-5 criteria plus impairment, and found nearly identical current prevalences (12.2% for male and 8.5% for female theater veterans). Because of ease of administration and diagnostic validity, the DSM-IV version of the PCL has become the backbone of epidemiologic research throughout the Iraq and Afghanistan wars.4,5 The NVVLS decision to rely on the DSM-IV version (appendedwith newDSM-5 symptoms) allows for direct comparisons across generations. The NVVLS documented a 10.3% prevalence using the original 17-item, 50-point cutoff, which is considered optimal for population research.5 This prevalencecompareswithaweightedmeanof6%acrosspopuRelated article page 875 Opinion