Serum brain-derived neurotrophic factor predicts responses to escitalopram in chronic posttraumatic stress disorder

IntroductionSome studies have found that antidepressants increase serum brain-derived neurotrophic factor (BDNF) levels in patients with major depression and the expression of BDNF mRNA in limbic structures of rats.ObjectivesThis study addressed whether the SSRI escitalopram increases serum BDNF levels in subjects with PTSD and whether BDNF levels are associated with treatment response.MethodsMedically healthy male subjects (N = 16) with chronic PTSD completed a 12 week open-label trial of flexible dose (5–20 mg/day) escitalopram monotherapy. BDNF levels were obtained at baseline, and at weeks 4, 8 and 12.ResultsPTSD symptoms significantly declined over the course of the 12 week escitalopram treatment. Despite a substantial improvement in PTSD symptoms, there was virtually no change in BDNF levels over time. Nevertheless, mean BDNF levels across the trial were strongly correlated with the slope of PTSD symptoms over the 12 weeks (r = 0.58, p = 0.018). Lower mean BDNF was associated with a greater decrease in PTSD symptoms over the course of the trial.ConclusionsPTSD subjects with low BDNF levels demonstrated the largest treatment response from an agent with putative neurotrophic effects.

Research highlights
► BDNF promotes neuronal survival and regulates the proliferation and differentiation of nerve cells in the peripheral and central nervous systems.
► Antidepressant medication can increase serum BDNF and neural progenitor cells in the hippocampus of patients with MDD.
► Patients with PTSD exhibit smaller hippocampal volumes than healthy controls and chronic treatment with antidepressants seems to reverse the hippocampal atrophy observed in these patients.
► We sought to determine whether serum levels of BDNF predict response to escitalopram in patients with PTSD.
► PTSD symptoms significantly declined over the course of the 12 week escitalopram treatment.
► Mean BDNF levels across the 12 week escitalopram trial were strongly correlated with the slope of PTSD symptoms.
► Low serum BDNF might be a biomarker predicting a favorable response to antidepressants in patients in PTSD.