Neuroimmune and cortisol changes in selective serotonin reuptake inhibitor and placebo treatment of chronic posttraumatic stress disorder

Abstract

Background To explore relations between neuroimmune and neuroendocrine systems relative to posttraumatic stress disorder (PTSD) treatment, cortisol and cytokine changes in response to selective serotonin reuptake inhibitor (SSRI) and placebo treatment of chronic PTSD were assessed prospectively. Methods Baseline measures of PTSD, depression, salivary 8 am and 4 pm cortisol, and serum interleukin-1β (IL-1β; pro-inflammatory) and soluble interleukin-2 receptors (IL-2R; cell-mediated immunity) were obtained for 58 PTSD and 21 control subjects. The PTSD subjects participated in a 10-week, double-blind treatment with citalopram ( n = 19), sertraline ( n = 18), or placebo ( n = 7). Results At baseline, PTSD subjects had significantly greater PTSD, depression, and IL-1β and lower IL-2R levels than control subjects, with no group differences found for am or pm cortisol levels. Both SSRI groups' IL-1β correlated negatively with IL-2R; neither cytokine correlated with cortisol levels. Treatment significantly lowered PTSD, depression, and IL-1β levels and increased IL-2R for all groups to control subject levels. After treatment, both SSRI groups' IL-1β correlated with an end cortisol measure (one negatively, one positively). Conclusions Our results support a complex relationship between neuroimmune and neuroendocrine systems with PTSD treatment. Implications of normalization of cytokine levels with effective SSRI treatment and placebo are discussed.