Introduction. Longitudinal prospective studies are needed to identify risk factors for posttraumatic stress disorder (PTSD) symptoms 15 years after trauma, since cross-sectional findings do not...Show moreIntroduction. Longitudinal prospective studies are needed to identify risk factors for posttraumatic stress disorder (PTSD) symptoms 15 years after trauma, since cross-sectional findings do not inform how a possible pattern change as the clinical condition extends. Recently, thyroid hormones were in the top fifteen most relevant biochemical predictors for PTSD symptom trajectory within one year after trauma. Moreover, peritraumatic distress (PD) is highly associated with PTSD symptom severity. Nevertheless, most studies did not investigate the course of PTSD 15 years after a serious injury. This study hypothesized that higher thyroid functioning acutely after trauma, and higher PD predicted higher 15-year PTSD symptom severity, while the thyroid functioning mediated the relation between PD and 15-year PTSD symptom severity. Methods. This longitudinal prospective study examined 452 serious injury survivors. Blood samples were obtained acutely after trauma, and PD 23 days after trauma. PTSD symptom severity was assessed 15 years after trauma (M = 2.77, SD = 4.64), with the Clinician Administered PTSD Scale. Results. Multiple linear regression analyses showed that 15-year PTSD symptom severity was not predicted by the thyroid hormones and PD, and the thyroid hormones did not mediate the relation between PD and 15-year PTSD symptom severity. Discussion. Our study showed the importance of predicting 15-year PTSD symptoms, since understanding how and when these symptoms occur could be crucial for treatment and promising for risk identification at an early stage. More longitudinal studies are needed to understand why some people do, and others do not develop 15-year PTSD symptoms.Show less
