Prevalence of Post-Traumatic Stress Disorder in Aging Vietnam-Era Veterans: Veterans Administration Cooperative Study 569: Course and Consequences of Post-Traumatic Stress Disorder in Vietnam-Era Veteran Twins.

Objective: The prevalence of post-traumatic stress disorder (PTSD) among aging Vietnam-era veterans is not well characterized.

Methods: In a cross-sectional study, 5,598 male Vietnam-era veterans and members of the Vietnam Era Twin Registry were assessed for PTSD using the Composite International Diagnostic Interview. Current symptoms were measured with the PTSD Checklist (PCL). PTSD was estimated according to age (<60 or ≥ 60) and Vietnam theater service.

Results: The lifetime prevalence of PTSD in theater veterans aged at least 60 years was 16.9% (95% CI: 13.9%-20.5%) and higher than the 5.5% (95% CI: 4.3%-7.0%) among nontheater veterans. Among veterans younger than 60 years, the comparable prevalence was 22.0% for theater (95% CI: 16.7%-28.4%) and 15.7% for nontheater (95% CI: 13.4%-18.2%) veterans. Similar results were found for theater service and current PTSD prevalence (past 12 months). PCL scores were significantly higher in theater compared with nontheater veterans in both younger and older cohorts. In both the younger and older cohorts significant differences in lifetime and current PTSD prevalence and PCL scores persisted in theater service discordant twin pairs.

Conclusion: Vietnam service is related to elevated PTSD prevalence and current symptom burden in aging veterans. More than 30 years after the end of the Vietnam conflict, many veterans continue to suffer from PTSD, which highlights the need for continuing outreach throughout the life course.