Abstract
Delayed-onset posttraumatic stress disorder (PTSD) is defined as a period of 6 months or more between trauma exposure and episode onset. Due to the limited research and lack of epidemiological studies on this form of the disorder, we investigated its prevalence, clinical features, and psychiatric comorbidities in a nationally representative sample of U.S. adults. Using National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III) data collected from individuals who met the DSM-5 criteria for PTSD (N = 1,980), we compared delayed- and immediate-onset PTSD with regard to demographic and clinical variables, including comorbidity with psychiatric and substance use disorder (SUD) diagnoses. The overall prevalence of delayed-onset PTSD was 11.0%. Respondents with delayed-onset PTSD were more likely than those with immediate-onset PTSD to report active military combat exposure, more physical and emotional difficulties, and higher levels of pain; these individuals were also more likely to be divorced and less likely to meet the diagnostic criteria for select SUDs. After adjusting for confounding variables, we found a decreased risk of delayed-onset PTSD among individuals with hallucinogen use disorder, OR = 0.30; 95% CI [0.11, 0.87], d = 0.5. We found no significant associations between PTSD onset status and any other SUD, including alcohol use disorder, after adjusting for covariates. Further longitudinal research is required to investigate the temporal associations between PTSD onset and its clinical characteristics and comorbidities, as this could have implications on disorder progression and treatment approaches.