BACKGROUND:

Two alternative models of post-traumatic stress disorder (PTSD) appear to represent the disorder's latent structure better than the traditional Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) three-factor PTSD model. The present study examines the impact of using these structural models for the diagnosis of lifetime PTSD while retaining the DSM-IV PTSD's six-symptom diagnostic requirement.

METHOD:

Data were gathered from large-scale, epidemiological datasets collected with adults (National Comorbidity Survey Replication) and adolescents (National Survey of Adolescents). Two alternative, empirically supported four-factor models of PTSD were compared with the DSM-IV three-factor PTSD diagnostic model.

RESULTS:

Results indicated that the diagnostic alterations resulted in substantially improved structural validity, downward adjustments of PTSD's lifetime prevalence (roughly 1 percentage point decreases in adults, 1-2.5 percentage point decreases in adolescents), and equivalent psychiatric co-morbidity and sociodemographic associations.

CONCLUSIONS:

Implications for modifying PTSD diagnostic criteria in future editions of DSM are discussed.