Mystery Behind Disparate Assessments of PTSD Prevalence in Vietnam Vets Resolved

Rates of PTSD in Vietnam veterans have been the subject of two large, government-funded studies. The Vietnam Experience Study (VES) found a prevalence of 2.2%, while the National Vietnam Veterans Readjustment Study (NVVRS) resulted in a much higher rate of 15.2%. The question of how two large studies could produce such different estimates of PTSD prevalence has now been cleared up. A new paper in BMC Psychiatry reports that the difference between the studies was the broadness of the criteria employed. Applying equally broad or narrow criteria to both studies reconciled the difference in estimates of prevalence. http://www.biomedcentral.com/1471-244X/6/19/abstract