Mild traumatic brain injury (TBI) is common among veterans who have served in OEF/OIF
(Operation Enduring Freedom in Afghanistan/Operation Iraqi Freedom) and other theatres.
Delayed symptoms may occur following TBI, including cognitive symptoms (impaired attention,
processing speed, executive functioning), as well as behavioral symptoms such as anxiety,
depression, and irritability (Fann et al. 2004; Holsinger et al. 2002). Neuroactive steroids
have neuroprotective effects in rodent models of TBI (Djebaili et al. 2005; Djebaili et al.
2004; He et al. 2004; Pettus et al. 2005; Roof et al. 1997) and the neuroactive steroid
pregnenolone and its sulfated derivative also markedly enhance learning and memory in rats
(Akwa et al. 2001; Flood et al. 1992; Flood et al. 1995; Vallee et al. 1997; Vallee et al.
2003). In humans, reductions in pregnenolone (George et al. 1994) and its GABAergic
metabolite allopregnanolone (Uzunova et al. 1998) have been associated with depressive
symptoms. Pharmacological intervention with the neuroactive steroid pregnenolone could
therefore result in a multi-targeted treatment approach, potentially improving cognitive
deficits as well as anxiety and depression symptoms following TBI.
1. 18-55 years of age, any ethnic group, either sex
2. History of mild TBI since September 2001. TBI occurring at age 18 or older.
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 the Glasgow
Coma Scale Score criteria (not available for these participants).
4. Ability to participate fully in the informed consent process.
5. No anticipated need to alter medications for the 10-week duration of the study.
1. For this pilot study, we will exclude patients who report a history of seizures.
2. Serious unstable medical illness. History of cerebrovascular accident, prostate,
uterine, or breast cancer. Use of oral contraceptives or other hormonal
supplementation such as estrogen.
3. Current active suicidal and/or homicidal ideation, intent or plan.
4. Concomitant medications for medical conditions will be addressed on a case-by-case
base and determined if exclusionary.
5. Current DSM-IV diagnosis of bipolar disorder, schizophrenia or other psychotic
disorder, or cognitive disorder due to a general medical condition other than TBI.
6. Female patients who are pregnant or breast-feeding.
7. Known allergy to study medication.