Could a natural hormone ease the hidden wounds of war?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. 21-65 years of age, any ethnic group, either sex. 2. History of mild TBI since 2001 and service in the U.S. Military since 9/11/01 (OEF/OIF/OND era). 3. We will adhere to the operational definition of mild TBI suggested by the World Health Organization Task Force (Holm et al 2005), with the exception of Glasgow Coma Scale score criteria (not available for these participants): a.) 1 or more of the following: confusion or disorientation, loss of consciousness for 30 minutes or less, post-traumatic amnesia for less than 24 hours, and/or other transient neurological abnormalities such as focal signs, seizure, and intracranial lesion not requiring surgery; Glasgow Coma Scale (GCS) score of 13-15 after 30 minutes post-injury or later upon presentation for health care (GCS unavailable). This WHO diagnostic definition of mild TBI is also consistent with the CDC Report to Congress on Mild TBI in the United States, September 2003 (specifically, altered consciousness attributable to the head injury \[=transient confusion, disorientation or impaired consciousness\] or self-reported loss of consciousness lasting 30 minutes or less). 4. Ability to read/understand English and to participate fully in the informed consent process. 5. No anticipated need to alter psychiatric or pain medications for duration of study involvement. 6. No changes in psychotropic or behavioral interventions during the study or in the 2 weeks prior to study enrollment. 7. Negative pregnancy test if female. Sexually active subjects are required to use a medically acceptable form of birth control if they are of childbearing potential and could become pregnant during the study. Exclusion Criteria: 1. Exclusionary criteria will diverge slightly from the above WHO definition of mild TBI and exclude participants who report a history of seizures for this investigation. 2. Participants with current suicidal or homicidal ideation necessitating clinical intervention or representing an imminent concern. 3. Concomitant medications for co-occurring medical conditions are permissible for stable medical conditions that are reasonably well-controlled (for example, hypertension medications, statins, and oral hypoglycemic medications would generally be permissible if they appear to be effectively treating the underlying condition). Medications that could potentially confound study outcomes (for example, prednisone) are exclusionary. 4. Participants who report a history of seizures, a history of stroke, a history of prostate cancer (or any other cancer other than non-melanoma skin cancer), a history of myocardial infarction, the presence of congestive heart failure, or any other serious health condition that would likely preclude safe study participation in the medical opinion of the PI or in consultation with the participant's PCP/other health care provider). 5. Current DSM-5 diagnosis of bipolar disorder, schizophrenia or other psychotic disorder, or cognitive disorder due to a general medical condition other than TBI. 6. Female participants who are pregnant or breast-feeding. 7. Known allergy to study medication. 8. Benzodiazepine or opioid use within the last 2 weeks is exclusionary. 9. Substance use disorder (DSM-5), other than nicotine use disorder. 10. Serious unstable medical illness. History of cerebrovascular accident, prostate, uterine or breast cancer. Medications to treat these conditions either acutely or chronically (for example, finasteride, tamoxifen, clopidogrel) are also exclusionary. 11. Use of oral contraceptives or other hormonal supplementation such as estrogen or progesterone, as there is a theoretical risk that a metabolite of pregnenolone could potentially impact efficacy of oral contraceptives and estrogen replacement.