Aim 1.1: To determine the effect of ibogaine treatment on executive functions as measured by the change in cognitive flexibility (D-KEFS Color Word, TMT, Verbal Fluency) from baseline to immediate post treatment in an observational study of individuals with a history of TBI. Aim 1.2: To determine the effect of ibogaine treatment on executive functions as measured by the change in cognitive inhibition (D-KEFS Color Word, number of errors) from baseline to immediate post treatment in an observational study of individuals with a history of TBI. Aim 1.3: To determine the effect of ibogaine treatment on executive functions as measured by the change in problem solving scores (D-KEFS Tower Test) from baseline to immediate post treatment in an observational study of individuals with a history of TBI. Aim 1.4: To determine the effect of ibogaine treatment on executive functions as measured by the change in verbal fluency scores (D-KEFS Verbal Fluency) from baseline to immediate post treatment in an observational study of individuals with a history of TBI. Aim 1.5: To determine the effect of ibogaine treatment on processing speed as measured by the change in PSI score (WAIS-IV Processing Speed Index) from baseline to immediate post treatment in an observational study of individuals with a history of TBI. Aim 1.6: To determine the effect of ibogaine treatment on working memory as measured by the change in WMI score (WAIS-IV Working Memory Index) from baseline to immediate post treatment in an observational study of individuals with a history of TBI. Aim 1.7: To determine the effect of ibogaine treatment on verbal memory as measured by the change in HVLT score from baseline to immediate post treatment in an observational study of individuals with a history of TBI. Aim 1.8: To determine the effect of ibogaine treatment on visuospatial memory as measured by the change in BVMT-R score from baseline to immediate post treatment in an observational study of individuals with a history of TBI. Aim 1.9: To determine the effect of ibogaine treatment on sustained visual attention as measured by the change in CPT3 scores from baseline to immediate post treatment in an observational study of individuals with a history of TBI. Aim 1.10: To determine the effect of ibogaine treatment on sustained visual attention as measured by the change in CPT3 scores from baseline to immediate post treatment in an observational study of individuals with a history of TBI.