Longitudinal associations between early post-injury serum BDNF levels and the development of post-traumatic stress disorder over two years.

Background: This study investigated the longitudinal associations between serum BDNF (sBDNF) levels measured early after injury and the onset of post-traumatic stress disorder (PTSD) across two years.

Methods: Patients with moderate to severe physical injuries were enrolled from a trauma center. At baseline, sBDNF levels were measured and a comprehensive socio-demographic and clinical data were collected. The range of time from physical injuries to blood collection was 1-28 days, with a median (IQR) of 8.0 (6.0) days. PTSD diagnoses were determined at 3, 6, 12, and 24 months post-injury using the CAPS-5. Linear regression analyses assessed the relationship between sBDNF levels and PTSD diagnoses.

Results: Out of 923 patients, 112 (12.1 %) developed PTSD during the study. Prevalence rates were 8.8 % at 3 months, 7.6 % at 6 months, 4.8 % at 12 months, and 3.7 % at 24 months. Significantly, lower sBDNF levels were associated with PTSD at 12 and 24 months, after adjusting for covariates and applying Bonferroni corrections, but not at earlier assessments.

Limitations: Focusing on patients with moderate to severe injuries from a single center may limit the findings' generalizability.

Conclusion: Early post-injury sBDNF levels are predictive biomarkers for PTSD, especially significant at 12 and 24 months post-injury.