Amantadine and Temporal Discrimination in Patients With Traumatic Brain Injury (TBI)

Inclusion Criteria: * Age 18 to 55 inclusive. History of post-MVA close head TBI. Female subjects must use an acceptable method of contraception during entire study. Acceptable methods of contraception are: history of surgical sterility, postmenopausal status, hormonal contraceptives, or accepted barrier devices (i.e., male/female condom, diaphragm, cervical cap, intrauterine device). Exclusion Criteria: * Current or past history of major psychiatric disorder (schizophrenia, bipolar disorder, major depressive disorder) * Substance use disorder * Current or past history of serious chronic medical condition (pulmonary (lung), cardiovascular (heart), hepato-renal (liver-kidney) disease, diabetes) * Seizures * Smoking one or more packs of cigarettes per day * If you are pregnant or breastfeeding, or plan to become pregnant during the study