Circulating endocannabinoids and genetic polymorphisms as predictors of posttraumatic stress disorder symptom severity: heterogeneity in a community-based cohort.

The endocannabinoid signaling system (ECSS) regulates fear and anxiety. While ECSS hypoactivity can contribute to symptoms of established post-traumatic stress disorder (PTSD), the role of the ECSS in PTSD development following trauma is unknown. A prospective, longitudinal cohort study of 170 individuals (47% non-Hispanic Caucasian and 70% male) treated at a level 1 trauma center for traumatic injury was carried out. PTSD symptom assessments and blood were obtained during hospitalization and at follow-up (6-8 months post injury). Serum concentrations of the endocannabinoids N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) were determined at both time points and selected genetic polymorphisms in endocannabinoid genes, including rs324420 in fatty acid amide hydrolase, were assessed. For the entire sample, serum concentrations of AEA at hospitalization were significantly higher in those diagnosed with PTSD at follow-up (p = 0.030). Serum concentrations of 2-AG were significantly, positively correlated with PTSD symptom severity at follow-up only in minorities (p = 0.014). Minority participants (mostly Black/African American) also demonstrated significant, negative correlations between serum AEA concentrations and PTSD symptom severity both measured at hospitalization (p = 0.015). The A/A genotype at rs324420 was associated with significantly higher PTSD symptom severity (p = 0.025) and occurred exclusively in the Black participants. Collectively, these results are contrary to our hypothesis and find positive associations between circulating endocannabinoids and risk for PTSD. Minority status is an important modulator of the association between endocannabinoids and risk for PTSD, suggesting that the ECSS contributes to risk most significantly in these individuals and the contextual factors related to these findings should be further explored.

Exploring the gold-standard: Evidence for a two-factor model of the Clinician Administered PTSD Scale for the DSM-5.

OBJECTIVE: The latent factor structure of posttraumatic stress disorder (PTSD) remains a source of considerable variability. The current study compared several a priori factor structures, as well as a novel 2-factor structure of posttraumatic psychological distress as measured by the Clinician Administered PTSD scale for the DSM-5 (CAPS-5). In addition, variability in diagnostic rates according to the divergent DSM-5 and ICD-11 criteria were explored. METHOD: The setting for this study was a Level 1 trauma center in a U.S. metropolitan city. Data were pooled from 2 studies (N = 309) and participants were administered the CAPS-5 at 1 (n = 139) or 6 months postinjury (n = 170). Confirmatory factor analysis (CFA) was used to compare several factor models, and prevalence rates based on DSM-5 and ICD-11 criteria were compared via z tests and kappa. RESULTS: CFAs of 5 factor structures indicated good fit for all models. A novel 2-factor model based on competing models of PTSD symptoms and modification indices was then tested. The 2-factor model of the CAPS-5 performed as well or better on most indices compared to a 7-factor hybrid. Comparisons of PTSD prevalence rates found no significant differences, but agreement was variable. CONCLUSIONS: These findings indicate that the CAPS-5 can be seen as measuring 2 distinct phenomena: posttraumatic stress disorder and general posttraumatic dysphoria. This is an important contribution to the current debate on which latent factors constitute PTSD and may reduce discordance. (PsycINFO Database Record