Lithium Augmentation for Hyperarousal Symptoms of Post Traumatic Stress Disorder: Pilot Study

Inclusion Criteria: * Combat Veterans seeking treatment at the Denver Veterans Affairs Medical Center. Subjects must be between the ages of 18-50 years old, have a diagnosis of Posttraumatic Stress Disorder and assessed with a Clinician Administered Posttraumatic Stress Disorder Scale scoring greater than 15 on the Clinician Administered Posttraumatic Stress Disorder Scale -D. Subjects may have a history mild traumatic brain injury. Subjects must also have a stable medical condition to be considered for the study. Both males and females will be included, and no exclusions will be made for race or ethnicity. Exclusion Criteria: * Subjects with substance dependence disorder less than two months prior to study enrollment; history of bipolar, psychotic and/or cognitive disorders; history of moderate-to-severe traumatic brain injury; seizure disorder; sensitivity to lithium or contraindications to lithium treatment; will not be included in this study. * Subjects currently enrolled in other intervention studies that may affect the outcome of this study, or where this study may affect the outcome of the other study, will not be included until the subject has completed their participation in the other study. * Women, who are pregnant, suspect that they are pregnant, or planning to become pregnant will not be enrolled into the study. * Subjects declared incompetent by the Veterans Health Administraytion or other legal authority will not be included for participation in this study. Additionally, research team members involved in the consenting process of the study will not enroll subjects whom appear incompetent to consent. Recruited subjects unable to comprehend the nature of the study, their involvement \& possible risks, described to them during the consent/enrollment process, will not be allowed to participate in the study for the respect of the volunteering subject, their safety, \& to ensure that volunteering subjects do not experience any coercion to participate in this study.