Exploring the association between lower serum BDNF levels and delayed-onset PTSD in physically injured patients with vulnerable personality traits: A two-year prospective study

This longitudinal study investigated the relationships among serum brain-derived neurotrophic factor (sBDNF) levels, personality types, and the development of posttraumatic stress disorder (PTSD), distinguishing between earlier- and delayed-onset PTSD over two years in individuals with physical injuries. A total of 895 adults with moderate to severe injuries were recruited from a trauma center and assessed within one month post-injury. Baseline evaluations included sBDNF measurements and personality assessments using the Big Five Inventory-10, which classified participants as having either resilient or vulnerable personality types. Comprehensive socio-demographic and clinical data were also gathered. PTSD diagnoses were made at 3, 6, 12, and 24 months post-injury using the Clinician-Administered PTSD Scale for DSM-5, with logistic regression analyses exploring the interactions among sBDNF levels, personality types, and PTSD onset. Of the total sample, 107 individuals (11.9 %) developed PTSD—76 (8.4 %) with earlier-onset and 31 (3.5 %) with delayed-onset PTSD. Lower sBDNF levels significantly predicted delayed-onset PTSD in those with a vulnerable personality type (N = 15). This finding was not detected in individuals with resilient personality traits (N = 16) or those with earlier-onset PTSD (N = 76). The findings suggest the intricate interplay between neurobiological vulnerabilities (sBDNF levels) and psychological predispositions (vulnerable personality types) in the genesis of PTSD, potentially deepening the understanding of PTSD etiology.