Neurosteroids in PTSD - Biomarkers to Therapeutics

This is a parallel-group, double-blind, placebo (PBO)-controlled, randomized Phase 2 pilot study using adjunctive dehydroxyepiandrosterone \[DHEA (400 mg)\] to establish Proof of Concept (POC) for use of this agent in Veterans with PTSD. The investigators' first objective is POC target engagement to evaluate a one-time adjunctive oral dose of DHEA (400 mg) relative to PBO on the neuronal circuity of fear-anxiety-emotion connectivity. This will be achieved by comparing pre- to post-treatment changes in amygdala-hippocampal functional connectivity to DHEA and PBO during fMRI activation. The investigators hypothesize that compared with PBO, DHEA will increase task-associated fMRI functional connectivity between the amygdala and hippocampus (primary outcome). The second objective is to determine if an 8-week treatment with adjunctive DHEA is superior to PBO in reducing symptoms of PTSD (CAPS-5) and depression (BDI) in OEF/OIF/OND Veterans, and enhancing resilience (CD-RISC). The investigators hypothesize that 400mg DHEA will result in reduced PTSD and depression symptom severity relative to PBO, as determined by a pre- to post-treatment decrease in CAPS-5 and BDI scores, respectively, with enhancement in resilience scores using the CD-RISC at 6-weeks. The third objective is to evaluate the impact of DHEA relative to PBO on serum neurosteroid levels in OEF/OIF/OND Veterans with PTSD. The investigators hypothesize that DHEA will result in a statistically-significant increase in serum neurosteroid levels (DHEA, DHEAS, androsterone) relative to PBO, as determined by pre- to post-treatment reductions in PTSD symptoms severity. This association will be evaluated by correlating neurosteroid levels with PTSD, depression, and resilience scores over 6 weeks of treatment. The exploratory objective is to determine preliminary evidence for an association of fMRI and myelin integrity measures of fear-anxiety-emotion circuits with serum neurosteroid levels and treatment response to DHEA. Changes in myelin integrity following DHEA treatment will be evaluated using novel susceptibility diffusion imaging \[STI\]), as DHEA impacts myelination in preclinical rodent models. The investigators will also determine if serum neurosteroid levels are correlated with myelin integrity on STI. The investigators hypothesize that fMRI and myelin integrity of fear-anxiety circuits will correlate with serum neurosteroids and treatment response.