BACKGROUND: There is an acute and urgent need to develop new and effective posttraumatic stress disorder (PTSD) pharmacotherapies, as there are currently only two FDA-approved medications for the treatment of PTSD (both of which are from the same drug class and have shown only moderate effect sizes in FDA registration trials). Many Veterans with PTSD thus remain symptomatic despite the availability of these treatments, increasing the likelihood of receiving pharmacological treatment interventions for which there is little or no empirical evidence. Multiple national and VA working groups focusing on PTSD have identified the critical need to address the paucity of PTSD pharmacotherapies, and have strongly recommended more randomized clinical trials to evaluate possible effective pharmacological treatments. Both preclinical and clinical data suggest that reductions in neurosteroids are involved in the pathophysiology of PTSD, and that ameliorating these deficits could potentially be clinically therapeutic - the proposed investigation targeting a neurosteroid intervention for the treatment of PTSD could thus be a promising research avenue. The investigators therefore propose to conduct a randomized clinical trial (RCT) to determine the efficacy of a neurosteroid intervention (pregnenolone) for PTSD and commonly co-occurring disorders in Iraq/Afghanistan-era Veterans, an understudied cohort that may be less treatment-refractory.

METHODS: This study will be a 10-week randomized, placebo-controlled, double-blind clinical trial of pregnenolone or matching placebo in Veterans with PTSD. The trial will include a 2-week single-blind placebo lead-in phase followed by 8 weeks of study medication (placebo or pregnenolone). Forty-five subjects meeting DSM-5 criteria for PTSD (as measured by a CAPS-5 score of 30) will be randomized to receive pregnenolone, and 45 subjects meeting DSM-5 criteria for PTSD will be randomized to receive placebo. The primary outcome for this RCT will be changes in total CAPS-5 score at Visit 6 for this modified intent-to-treat sample. Secondary clinical outcomes for this RCT include changes in pain intensity and functional interference, as measured by the Brief Pain Inventory, Short Form (BPI-SF) and depression symptoms by the Hamilton-Depression Rating Scale (HAM-D). Blood samples will be collected for serum analysis at all study visits and frozen in a -80 degree freezer. Upon completion of the study, samples will be thawed and analyzed using Gas Chromatography/Mass Spectrometry for neurosteroid analyses and inflammatory markers will be quantified. Genetic analyses will be conducted to determine therapeutic response.

PREDICTED RESULTS: The investigators hypothesize that treatment with pregnenolone will be efficacious in Iraq/Afghanistan-era Veterans with PTSD, and will significantly reduce PTSD symptoms as assessed by the CAPS-5 (primary endpoint) compared to placebo. Secondary endpoints will include the assessment of conditions that frequently co-occur with PTSD; specifically, the investigators hypothesize that pregnenolone will also demonstrate efficacy for co-occurring chronic pain symptoms and depression symptoms. The investigators hypothesize that increases in pregnenolone and other neurosteroids (and decreases in inflammatory markers) will predict improvements in PTSD, depression, and chronic pain symptoms. The investigators also hypothesize that neurosteroids are dysregulated in PTSD, and that specific SNPs of genes coding for neurosteroidogenic enzymes will be associated with therapeutic response.