The Role of Inflammation in Late-Life Post-Traumatic Stress Disorder

Introduction: There is evidence that immune system dysregulation and inflammation may play a role in the development of post-traumatic stress disorder (PTSD). Previous studies have reported elevated levels of inflammatory markers such as C-reactive protein (CRP) in individuals with PTSD. However, it is unclear whether exacerbation of PTSD symptoms late in life is also associated with elevated inflammation. The purpose of this pilot study was to examine the relationship between inflammation and late-life PTSD. Methods: We recruited veterans either diagnosed with PTSD after the age of 55 or with no diagnosis of PTSD. Six veterans did not meet all eligibility criteria, including five who did not meet criteria for PTSD and one with celiac disease. The final sample included a total of 32 male veterans (16 veterans diagnosed with PTSD after 55 and 16 veterans without PTSD). The groups were matched as closely as possible on age, body mass index, and combat exposure. PTSD symptoms were assessed using the Clinician-Administered PTSD Scale for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and depressive symptoms were assessed using the Hamilton Rating Scale for Depression. Inflammation was measured using serum CRP level. Results: The two groups did not differ on sample characteristics including age, body mass index, tobacco use, medication use, and military history. CRP level was found to be significantly higher in the PTSD group than in the comparison group (Z = -3.047, p = 0.002), which was also observed after adjusting for depression scores (F(1,27) = 8.30, p = 0.0077). Conclusion: The results from this pilot study suggest that late-life PTSD may be associated with increased inflammation. Further research in larger samples is needed to corroborate these findings and to clarify the relationship between inflammation and PTSD, which may lead to improved methods of diagnosis and treatment.